Let Us Save Energy

Hybrid Car ; Toyota Prius Generation III with the 1000 Patent

2009-04-25T13:02:00.010+07:00

Kompas.
When you have the money and abundant love with the latest technology, Toyota Prius Generation (Gen) III should be considered as a car that will be purchased. Section, which authorized the car will be launched in mid-2010 this issue a lot of the latest advanced technology. So, not just thrifty!

Currently, Prius Gen3 displayed in the Cobo Center, Detroit Auto Show 2009, the public interest for the United States and internationally.
1000 Patent. See the technology carried on the Prius and the new equipment, we can understand the price so expensive. Once complete! due, according to Toyota not less than 1000 patents used in the car to improve its performance and in accordance with the wishes of the present consumers. Also added, all of these patents, 292 patents come from the United States. Not yet known, whether derived from the 'brain' people of Indonesia.

Toyota Prius is very glory and make it as a "benchmark" cars of the future. This can be advised because this time, Prius has been owned by one million people around the world for 10 years, since first launched in 1997. In fact, since the second generation introduced in 2004, the number of Prius sold in the United States reached 670,000 units.

Popularity Prius hybrid car has not been as invincible. Reasonable course, Honda, Toyota among major competitors of Japan, is now campaigning for incentive same type of car, the Insight. The plan, Honda offers a cheaper price of the Prius that can compete globally.

However, when you see a feature that is included in the new Prius, the Honda is quite heavy for the Prius, in addition to relying on consumption of fuel is more economical, which is 21 km / liter, the latest advanced safety equipment.
Ecological plastic. Environmental aspects into focus in the Toyota Prius recently. Emissions are not only friendly to the environment, as well as material. Now the used plastic is made from plants (not oil) and is called plastic. With this, in addition to easy recycling, of course, does not damage the environment.

Atkinson cycle. As a source of prime, Toyota four-cylinder engine uses 1.8 liters of working with the Atkinson cycle. Election machine with a larger aim to get on the lap of torsion low. Target onwards, the consumption of fuel economical. Engine power is not preferred. Therefore, not surprisingly, workers produced only 98 PS engine.

Efforts to create a Toyota Prius engine work more efficiently done with the mechanical components with the power. Therefore, the radiator pump, driven by the electric power and no longer rely on direct energy from the engine. Belt system to operate the radiator fan, AC compressor, Alternator, and also replaced with the electric motor.

Development is the other dimension and weight of the inverter is lighter and smaller. Inverter is a tool to change the direct current (DC) to flow back and either (AC). The inverter, electric motor, trans axle, and also reduce the weight to 20 percent. In addition, the ability to work regenerative brake system (the best restore energy) controlled the electronic logic.
Mode 3. This new Prius offers three alternative mode driving. EV-Mode Drive, a car race with the use of energy from the battery only in low speed for distance around 1.6 km / hour (depending on battery condition). There is also a Power Mode, power to make the car faster and more responsive to the gas pedal board. Last is the Eco Mode, race the car with fuel consumption is economical.

Bottom Cd. Prius is a new test in the wind tunnel is longer than other cars in the history of Toyota. Result, the profile aerodynamics Prius or Cd is the lowest in the world at this time for cars, mass product, which is 0.25. For body shape, hollow, Fender, the form of a wheel with very carefully designed by the engineer and the design of Toyota.

solar energy. The new Prius is equipped with the moon roof of glass that can be incorporated with in slide and solar cell panels. Electrical energy produced solar panel used to set the ventilation air in the car, including when to parking. Another way to energy save the Toyota is using LED lights for the front, rear lights, and brake.

Weight of the car is also lighter. This could be because the engine hood, back door, front axle and Suspense caliper made of aluminum. Result, acceleration 0-96 km / hour is 9.8 seconds, while for the tooth movement, using the Toyota shift by wire system.

Additional sensors are touch switch on the handlebar that is designed to reduce driver eye movement. With this, it is expected that the concentration level driver to the higher road.
Security equipment. The new Prius is equipped with a security system because the top will be sold globally.

For the balloon or SRS (air bag), not only is installed in front of the driver and front passenger. All the doors also been the model of balloon curtains so that drivers and passengers safe when hit by a section on the side. Even for the driver and front passenger, added nothing to the balloon.

In addition to the standard, also have additional security options, namely Dynamic Radar Cruise Control (using millimeter wave radar), Lane Keep Assistant (help drivers stay safe on the track), Pre-Collision System (functioning safety belt to work faster and the brakes on the condition to avoid a collision).

Toyota also offers the Intelligent Parking Assist generation driver that's easy to park in a limited area. Also included in the monitoring of objects behind the car, especially when the back, plus a navigation system with voice activated.

Connect the other is safety, security services, among others, will notice the occurrence of collision, determine the location of the vehicle when stolen, and the SOS call button. Safety Connect available several months after launch.

Although the more sophisticated, unfortunately for the battery, Toyota still rely Nimh. The price can not estimated. Toyota new car prices will determine this before the launch next year. Who knows if there is price correction material prices go down!

How Hybrid Car Work

2009-03-30T13:33:00.007+07:00

Hybrid gas-electric cars really aren't that complicated. Add an electric motor and rechargeable batteries to the conventional gas engine—and see your efficiency increase by as much as 50 percent. The on board computer does all the hard work of switching between gas and electric power.

How Hybrids Work

Hybrid Engine

Selfishness: the Causes of Environmental Degradation and Natural

2009-03-29T03:32:00.003+07:00

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What is the relationship with environmental selfishness? There! selfishness and passivity are the causes of the occurrence of any environmental problems that we experienced this day.
Many of us only have time without the comfort of the impact that will occur in the environment around us and the global environment as a whole. Have felt only because of money, we do not heed warnings and Call to make energy savings.
"Ah, whatever I can afford the electricity bill is. So it's up to me to get the electricity at my heart. I afford to buy fuel whatever I want, so it's up to me I want to buy a car that is as extravagant. "
try to think: How much energy and resources that must be useless just because people want to enjoy the convenience that actually does not really need them. How much energy and resources are useless just because they want to appear prestigious.
People often buy things they do not need, change the items that should still be used only for the reasons bored. We never think how much energy and resources of this planet that is damaged to meet the needs we are selfish.
remember one thing: Money can buy you are 10 or 100 liters of fuel, but the money can not restore every liter of fuel that has been taken from the natural need millions of years to produce the fuel that you enjoy it.
Do not think comfort of your own life. At least, think the next generation to you, they have to do with his life all the resources are very limited because the behavior of parents, grandmother, grandfather in the past.
Then you will think, but we do not have alternative energy such as bio-fuel, hydrogen, and others? Still all is not free, there is always a need to sacrifice. Bio fuel cause environmental damage because of the fuel plants require land that is not small. Hydrogen is still expensive and not yet can be produced efficiently. What if our planet is destroyed first before we can enjoy all the comfort of these technologies?
So many people in other parts of the world requires a highly fuel drops each of us enjoy, each drops of water that we enjoy, and things other basis to support their lives. let sparingly in all forms of energy that you can. Do it for the world, the next generation to do it for you.

CAR PARKING IN THE BUILDING

2009-03-28T22:58:00.002+07:00

Image description :
Position 1: Position the car park leads to the constraint.
Position 2: Position of car parking distance constraint.
Function: When emergency occurs, the car in position NO.2 faster in the evacuation

10 tips to save fuel cars

2009-02-26T17:57:00.002+07:00

By Aaron Gold, About.com

Filed In:

Fuel Economy

Whether you drive a two-seat hybrid or a three-ton SUV, chances are you can squeeze a bit more distance out of each gallon of fuel -- and at today's gas prices, an improvement of just one or two miles per gallon (MPG) can really add up. These ten fuel saving tips have served me well over the years, and they can help you improve your car's fuel economy and take some of the sting out of high fuel prices. Most of these tips will give you a very slight increase in MPG -- but use several together and the gas mileage improvements will really add up.

1. Slow down

One of the best ways to save gas is to simply reduce your speed. As speed increases, fuel economy decreases exponentially. If you one of the "ten-over on the freeway" set, try driving the speed limit for a few days. You'll save a lot of fuel and your journey won't take much longer. (Just be sure you keep to the right, so you won't impede the less-enlightened.)

2. Check your tire pressure

Under-inflated tires are one of the most commonly ignored causes of crummy MPG. Tires lose air due to time (about 1 psi per month) and temperature (1 psi for every 10 degree drop); under-inflated tires have more rolling resistance, which means you need to burn more gas to keep your car moving. Buy a reliable tire gauge and check your tires at least once a month. Be sure to check them when they are cold, since driving the car warms up the tires along with the air inside them, which increases pressure and gives a falsely high reading. Use the inflation pressures shown in the owner's manual or on the data plate in the driver's door jamb.

3. Check your air filter

A dirty air filter restricts the flow of air into the engine, which harms performance and economy. Air filters are easy to check and change; remove the filter and hold it up to the sun. If you can't see light coming through it, you need a new one. Consider a K&N or similar "permanent" filter which is cleaned rather than changed; they are much less restrictive than throw-away paper filters, plus they're better for the environment.

4. Accelerate with care

Jack-rabbit starts are an obvious fuel-waster -- but that doesn't mean you should crawl away from every light. If you drive an automatic, accelerate moderately so the transmission can shift up into the higher gears. Stick-shifters should shift early to keep the revs down, but don't lug the engine -- downshift if you need to accelerate. Keep an eye well down the road for potential slowdowns. If you accelerate to speed then have to brake right away, that's wasted fuel.

5. Hang with the trucks

Ever notice how, in bad traffic jams, cars seem to constantly speed up and slow down, while trucks tend to roll along at the same leisurely pace? A constant speed keeps shifting to a minimum -- important to those who have to wrangle with those ten-speed truck transmissions -- but it also aids economy, as it takes much more fuel to get a vehicle moving than it does to keep it moving. Rolling with the big rigs saves fuel (and aggravation).

6. Get back to nature

Consider shutting off the air conditioner, opening the windows and enjoying the breeze. It may be a tad warmer, but at lower speeds you'll save fuel. That said, at higher speeds the A/C may be more efficient than the wind resistance from open windows and sunroof. If I'm going someplace where arriving sweaty and smelly could be a problem, I bring an extra shirt and leave early so I'll have time for a quick change.

7. Back off the bling

New wheels and tires may look cool, and they can certainly improve handling. But if they are wider than the stock tires, chances are they'll create more rolling resistance and decrease fuel economy. If you upgrade your wheels and tires, keep the old ones. I have fancy sport rims and aggressive tires on my own car, but I keep the stock wheels with a good narrower-tread performance tire in the garage. For long road trips, the stock wheels give a smoother ride and better economy.

8. Clean out your car

If you're the type who takes a leisurely attitude towards car cleanliness -- and I definitely fall into that category -- periodically go through your car and see what can be tossed out or brought into the house. It doesn't take much to acquire an extra 40 or 50 lbs. of stuff, and the more weight your car has to lug around, the more fuel it burns.

9. Downsize

If you're shopping for a new car, it's time to re-evaluate how much car you really need. Smaller cars are inherently more fuel-efficient, and today's small cars are roomier than ever -- one of my favorite subcompacts, the Nissan Versa, has so much interior room that the EPA classifies it as a mid-size. Worried about crash protection? The automakers are designing their small cars to survive crashes with bigger vehicles, and safety features like side-curtain airbags and electronic stability control are becoming commonplace in smaller cars.

10. Don't drive

Not a popular thing to say on a car site, I know, but the fact is that if you can avoid driving, you'll save gas. Take the train, carpool, and consolidate your shopping trips. Walking or biking is good for your wallet and your health. And before you get in your car, always ask yourself: "Is this trip really necessary?"
source from: http://cars.about.com/od/helpforcarbuyers/tp/ag_top_fuelsave.htm

Global Warming Effect

2009-02-20T22:41:00.005+07:00

Ice Under Fire: Antarctica

The disintegrating face of the Müller Ice Shelf, Lallemand Fjord, Antarctic Peninsula, 67° South, April 2, 1999. This small shelf, fed by glaciers from the Loubet Coast, has been receding recently after growing over a 400-year cooling period. Like other receding ice shelves such as the larger Larsen, it may be a sensitive monitor of rising regional temperatures. The Larsen Ice Shelf lost a 1200 square mile section early in 2002. Earlier in the 1990's other huge sections of this shelf disintegrated. In 2003 Argentine glaciologists reported that the land-based glaciers exposed by the removal of those sections had surged rapidly into the ocean. Thus, although ice shelves are floating and do not add to sea level when they melt or break up, land based glaciers released by such events definitely will add to sea level.

Another view of the Müller Ice Shelf calving rapidly (right). Across the Peninsula, seven monitored ice shelves have declined by a total of about 13,500 km² since 1974, according to the National Snow and Ice Data Center. This is nearly the area of Connectcut. On the Larsen shelf (satellite view left), about 3,250 km² of shelf in area B disintegrated in a 35-day period beginning on 31 January 2002. Eugene Domack, Hamilton College geologist, and others believe this portion of the shelf may have been stable for about 12,000 years before this year's collapse.

Technicians for the National Science Foundation on the rear deck of the research vessel, Nathaniel B. Palmer, prepare a kasten core device to lower into sediment near the Müller Ice Shelf. This is during a study by Dr. Eugene Domack, funded by the National Science Foundation, on the history of climate in peninsular Antarctica. All ice shelves in the area have been receding, but because they were already floating they do not raise sea level. The concern is that landed glaciers behind the shelves may be next to begin rapid retreat, which would raise ocean levels.

This mile-long ice cliff of Marr Ice Piedmont, Anvers Island, has receded about 500 meters since the mid 1960s. The cliff's previous position was to the left of the line of ice floating in the harbor and extended to the headland at the extreme upper left. The regional temperature has increased 5° C in winter over the past 50 years. This reduces seasonal icepack, disrupts growth of krill and changes conditions on penguin rookeries.

For more on glacier recession and around the world, please see Ice Under Fire, the Mountain Glacier section.

Pushing the Boundaries of Life: Antarctica

A colony of Adelies on Humble Island, one of eight islets off Anvers Island where thousands of Adelies have nested for some 600 years. Over the last 25 years these Adelie colonies have declined sharply. Chinstrap penguins are moving rapidly into Adelie territory. Archaeological digs in penguin colonies indicate there probably were no chinstraps in this area until about 50 years ago, when average temperatures began to rise.

Ornithologist Bill Fraser stands on the smooth pebbly surface of a former large colony of Adelie penguins on Torgersen Island. Unlike the colony in the photo above, this nesting site has been used by fewer and fewer penguins over recent years. Analyzing climate data, island topography, and breeding statistics, Fraser believes climate change caused the loss of half of its 16,000 nesting Adelies. Warming temperatures and more open water make for greater snowfall and more difficult hunting for krill, affecting nesting success. These changes are seen in other Adelie colonies on the Antarctic peninsula, but elsewhere in Antarctica, climate change either is favorable to the birds or is not affecting them.

A male Adelie penguin, back from a long feeding trip, disgorges krill for its chick. Krill develop best under seasonal ice, so thinner, less extensive winter ice can reduce the size of the shrimp-like Antarctic staple. The tiny radio transmitter on this bird's back allows Dr. Fraser to monitor how far and for how long penguins hunt for food. For some colonies, hunting times are becoming longer and longer as diminished seasonal sea ice extends the distance from rookery to feeding ground.

Although the Adelie penguin is not threatened as a species by global warming or man-caused problem so far, many species of this bird are. In a landmark decision that nevertheless fell short of conservationists' proposals, the US Fish and Wildlife Service proposed seven penguin species as candidates for 'threatened" status under the Endangered Species Act.

Included in the December 2008 document are the African penguin, yellow-eyed penguin, white-flippered penguin, Fiordland crested penguin, Humboldt penguin, and erect-crested penguin and a portion of the range of the southern rockhopper penguin. However, the ruling denied listing for the majority of the range of the southern rockhopper penguin, as well as for the northern rockhopper penguin, macaroni penguin, and emperor penguin.

The emperors, the ones in the film "March of the Penguin" are among species which are losing numbers apparently due to warming seas, reduced summer sea ice, and lack of their prime food, krill. If the candidate species are found by additional study and public comment to be worthy of being listed, they will receive protection under the Endangered Species Act sometime in 2009.
http://www.worldviewofglobalwarming.org/pages/antarctica2.html

Global Warming

2009-02-19T01:10:00.009+07:00

Global Warming

Upsetting a delicate balance In the past the Earth's climate has changed as a result of natural causes in our atmosphere.

The changes we are witnessing and those that are predicted are largely due to human behaviour: we are burning fossil fuels, and heating up the planet at the same time. We blow exponential amounts of carbon dioxide (CO₂) into the atmosphere every year – 29 billion tonnes of it (2004) and rising – and this warms the globe.

Since the Industrial Revolution, humans have been burning fossil fuels on a massive scale. We use this energy, almost without care for the consequences, to run vehicles, heat homes, conduct business, and power factories.

Burning fossil fuels releases carbon dioxide stored millions of years ago as oil, coal or natural gas. In the last 200 years we have burned a large part of these stores, resulting in an increase in CO₂ in our atmosphere. Deforestation also releases CO₂ stored in trees and in the soil.

The increase of CO₂ in the atmosphere thickens the 'greenhouse blanket', with the result that too much heat is trapped into the Earth's atmosphere. This causes global warming: global temperatures rise and cause climate change.

Note: CO₂ is the most important gas causing global warming. Others include methane (CH₄), nitrous dioxide (NO₂), and several artificial gases (Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs); and Sulphur hexafluoride (SF₆). These 6 groups are accounted for under the Kyoto Protocol.

Sea Ice Extent Comparison at the North Pole - mimumum ice reach comparison between 1979 and 2005. © NASA

Current statistics

Data from the World Resources Institute show that humans have added 2.3 trillion tonnes of CO₂ to the atmosphere in the last 200 years. Half of this amount was added in the last 30 years. The largest absolute increase in CO₂ emissions occurred in 2004, when burning fossil fuels alone added more than 28 billion tonnes to the atmosphere.
Source: WRI, Navigating the numbers, based on data from IEA, EIA, Marland et al, and BP.

Overall, the concentration of CO₂ in the atmosphere has increased by 31% since 1750, i.e. since the Industrial Revolution. CO₂ emissions are now around 12 times higher than in 1900 as the world burns more and more coal, oil and gas for energy. A 1999 study by Mann et al. shows the dramatic increase in temperature in the Northern Hemisphere in the last 50 years. This well-known hockey stick curve has been validated by numerous other scientists.

The (not too distant) future

We simply cannot continue pumping CO₂ into the atmosphere without curbs and controls. Even with the best case scenario for the increase in CO₂ emissions it is predicted that the concentration of CO₂ in the atmosphere will reach double the level of before the Industrial Revolution by 2100. The worst case scenario brings this doubling forward to 2045 – less than 40 years from now! The Third Assessment Report of the UN's Intergovernmental Panel on Climate Change (IPCC) predicts global temperature rises by the end of the century of between 1.4°C and 5.8°C.

The Earth’s climate is driven by a continuous flow of energy from the sun. Heat energy from the sun passes through the Earth’s atmosphere and warms the Earth’s surface.

The fragile atmosphere protects us from the universe.

As the temperature increases, the Earth sends heat energy (infrared radiation) back into the atmosphere. Some of this heat is absorbed by gases in the atmosphere, such as carbon dioxide (CO₂) , water vapour, methane, nitrous oxide, ozone and helacarbons.

The greenhouse effect

These gases, which are all naturally occurring, act as a blanket, trapping in the heat and preventing it from being reflected too far from the Earth. They keep the Earth's average temperature at about 15°C: warm enough to sustain life for humans, plants and animals. Without these gases, the average temperature would be about minus 18°C - too cold for higher life. This natural warming effect is also sometimes called the greenhouse effect.

Carbon dioxide (CO₂)

CO₂ is the most significant of the gases in our atmosphere which keep the Earth warm. Four billion years ago its concentration in the atmosphere was much higher than today (80% compared to today's 0.03%), but most of it was removed through photosynthesis over time. All this carbon dioxide became locked in organisms and then minerals such as oil, coal and petroleum inside the Earth's crust.

The natural carbon dioxide cycle

A natural carbon dioxide cycle keeps the amount of CO₂ in our atmosphere in balance. Decaying plants, volcanic eruptions and the respiration of animals release natural CO₂ into the atmosphere, where it stays for about 100 years. It is removed again from the atmosphere by photosynthesis in plants and by dissolution in water (for instance in the oceans).

The amount of naturally produced CO₂ is almost perfectly balanced by the amount naturally removed. Even small changes caused by human activities can upset this equilibrium.

The world is warming faster than at any time in the last 12,000 years. The 1990s was the hottest decade in the past millennium.

As global warming tightens its grip, the effects are being felt from the highest mountain peaks to the depths of the oceans. In just the last few years there are numerous examples of how this is affecting people and nature all over the world.

Global warming is melting glaciers in every region of the world, putting millions of people at risk from floods, droughts and lack of drinking water.
March 2006 showed the smallest Arctic sea ice cover ever measured. In the space of one year an area about the size of Italy was lost. The National Snow and Ice Data Center in the United States found that sea ice extent had reduced by 300,000 square km in comparison to March 2005, itself already a record low year.
2003, Scotland's hottest year on record, saw hundreds of adult salmon die in Scotland’s famous fisheries, as rivers became too warm for salmon to be able to extract enough oxygen from the water.
Coral reefs around the world have been severely damaged by unusually warm ocean temperatures. The Caribbean saw its warmest ever ocean temperatures in 2005, combined with the worst coral bleaching ever. At the current rate of degradation, the entire Great Barrier Reef could be dead within a human lifetime.
Cities like Athens, Chicago, Milan, New Delhi and Paris have sweltered under heatwaves. The 2003 summer heatwave in Europe killed 14,800 people in France alone, according to official figures released in September 2003. The French National Institute for Health and Medical Research said that the death rate was on average 60% higher than usual.
Summer temperatures in European capitals have increased by up to 2°C over the last 30 years, a WWF report showed.
Rising sea levels threaten entire nations on low-lying islands in the Pacific and Indian Oceans. Read how WWF South Pacific tries to help concerned villagers.
A report released by WWF and leading meteorologists shows that human-induced global warming was a key factor in the severity of the 2002 drought in Australia, generally regarded as the worst ever.

What is Climate Change ?

2009-02-18T01:09:00.001+07:00

Earth’s climate is changing. Greenhouse gases are accumulating. Human activities are the cause.

Further Resources

»	The Intergovernmental Panel on Climate Change (IPCC)
»	Summary for Policymakers of the Synthesis Report of the IPCC Fourth Assessment Report

The build-up of greenhouse gases (GHGs) threatens to set the Earth inexorably on the path to a unpredictably different climate. The Intergovernmental Panel on Climate Change (IPCC) says many parts of the planet will be warmer. Droughts, floods and other forms of extreme weather will become more frequent, threatening food supplies. Plants and animals which cannot adjust will die out. Sea levels are rising and will continue to do so, forcing hundreds of thousands of people in coastal zones to migrate.

One of the main GHGs which humans are adding to the atmosphere, carbon dioxide (CO2), is increasing rapidly. Around 1750, about the start of the Industrial Revolution in Europe, there were 280 parts per million (ppm) of CO2 in the atmosphere. Today the overall amount of GHGs has topped 390 ppm CO2e (parts per million of carbon dioxide equivalent – all GHGs expressed as a common metric in relation to their warming potential) and the figure is rising by 1.5–2 ppm annually. Reputable scientists believe the Earth’s average temperature should not rise by more than 2°C over pre-industrial levels. Among others, the European Union indicated that this is essential to minimize the risk of what the UN Framework Convention on Climate Change (UNFCCC) calls dangerous climate change and keep the costs of adapting to a warmer world bearable. Scientists say there is a 50 per cent chance of keeping to 2°C if the total GHG concentration remains below 450 ppm.

WHAT CAN YOU DO?

Climate change is here to stay. But it is still in our power – as individuals, businesses, cities and governments – to influence just how serious the problem will become.

Further Resources

»	Climate Neutral Network Website
»	Kick the Habit: A UN Guide to Climate Neutrality
»	Twelve Steps to Help You Kick the CO2 Habit
»	Climate Change Adaptation and Mitigation in the Tourism Sector

Whether you are an individual, an organization, a business or a government, there are a number of steps you can take to reduce your carbon emissions, the total of which is described as your carbon footprint. You may think you don’t know where to begin, but by reading this, you have already begun.

Indeed, some quite simple ‘no regrets’ measures can more than halve the daily emissions of an individual, with even bigger cuts possible if sectors like power suppliers and automobile makers as well as aviation and appliance manufacturers contributed more to the greening of global lifestyles.

Individuals who reduce their energy consumption and thus their climate impact also save money. On a more macro-economic level, economic opportunities arise from measures taken to reduce GHGs: insulating buildings for example will not only save energy costs, but also give the building sector an enormous boost and create employment. While some sectors might suffer increased costs, many will seize the opportunity to innovate and get a step ahead of their competitors in adapting to changed market conditions.

Many companies, cities, organizations and indeed whole countries are embarking on strategies to achieve even zero emission businesses, communities and economies. A great deal of this transition to a green economy is being federated and empowered under the banner of UNEP's Climate Neutral Network (CN Net) which was launched in February 2008.

Some low-carbon lifestyle choices at home, in the office and when traveling include:

Waking up with a traditional wind-up alarm clock rather than the beep of an electronic one - this can save someone almost 48 grams (g) of CO2 each day;
Choosing to dry clothes on a washing line versus a tumble dryer - a daily carbon diet of 2.3 Kg of CO2;
Replacing a 45-minute workout on a treadmill with a jog in a nearby park. This saves nearly 1 Kg of the main greenhouse gas;
Opting for non-electric toothbrush will avoid nearly 48g of CO2 emissions;
Heating bread rolls in a toaster versus an oven for 15 minutes saves nearly 170g of CO2;
Switching from regular 60-Watt light bulbs to energy-saving ones will produce four times less greenhouse gas emissions;
Taking the train rather than the car for a daily office commute of as little as 8 km will save a big 1.7 Kg of CO2;
Shutting down your computer and flat screen both during lunch break and after working hours will cut CO2 emissions generated by these appliances by one-third;
Investing in a water-saving shower head will not only save 10 liters of water per minute, but will also slash CO2 emissions resulting from a three-minute hot shower by half;
Reducing the weight of goods and items carried onboard by airline passengers to below 20Kg could cut global GHG emissions by two million tonnes of CO2 a year.

AC Control

2009-02-11T10:46:00.001+07:00

Tips & Tricks

Controls
The ultimate objective of any serious energy conservation program for a sizeable facility is a central, computer automated electronic controls system. This integrated system of remote sensors and control devices permits the optimum use of energy in all areas while simultaneously providing the best environment for building occupants.

Optimized start/stop of air handling units
This is a more sophisticated use of the on/off controls of all the air handling units in a building. Instead of a complete cut off of power to a unit the thermostat setting is setback at night and on weekends. The advantage over full on/off controls is that when units are turned off all night they must work extra hard to return the space to the comfort zone in the morning. This is especially important during the heating season, when the peak load often occurs shortly after the office opens in the morning.

Operation of the equipment to maintain a nominal space temperature all night reduces the energy needed to start up, so the equipment can be sized to satisfy a smaller peak load. This, in turn, translates into less expensive air handlers and ones that operate nearer their most efficient, full load condition.

Another common use of the central control of air handlers is to turn the equipment off, or initiate the night setback sequence, an hour or two before the end of the day. The thermal momentum of the building mass and the volume of air already conditioned will maintain space temperatures within the comfort zone for the balance of the day. This affect is especially useful when the supply and return air fans continue to circulate air after the heating or cooling system is disabled, thereby extracting any residual heat from the circulating fluids or the building mass. The continued movement of air, even as the temperature floats away from the setpoint, will make the space more comfortable to the occupants.

Demand limiting
The demand limiting philosophy is to begin turning off pieces of equipment as the electrical use approaches the peak. The software, already programmed with a prioritized list of items to be turned off, simply follows the list until the energy use curve is leveled off and the peak load passes. Clever programmers will make use of the building mass to provide some thermal momentum during these periods, extracting or rejecting heat to the building while the HVAC is turned off to always maintain a comfortable environment.

Peak load shifting
Some systems accomplish demand limiting by shifting the building load to off peak hours. One way to do this is to run the chillers during the night to chill water that is stored in large tanks on the premises. Then during the peak building load the following day the chillers are turned off and the ready-made chilled water is circulated to the building loop. Other systems make ice in the night and melt it later to chill the loop water.

This same sort of technique can be used on a smaller scale, using simple controls. There are several thermal masses that can be used to store energy during off-peak hours: the building mass, the volume of fluid in the chilled water loop, the volume of cooled air within the building and the humidity of the cooled air in the building. An hour or two before the peak load is expected (based on an average of previous days, or other criteria) the building and its systems are allowed to float below the set point, storing energy that is released for the next few hours until the peak is passed.

The immediate demand on the system is met by the existing air volume, then by the chilled water resident in the closed loop. The air humidity then drifts upward as the warmer air is able to absorb thermal energy from the building environment. Finally, the building mass contributes to the system.

Keep in mind that the peak load that the system is designed to handle typically lasts only a couple of hours. Use of the aforementioned dynamic elements, eg letting the temperature and humidity drift upward in the process, will greatly reduce the daily peak load. Also, since this load is usually at the end of the work day the entire system will be shut down soon and no additional energy will have to be input to make up for the excesses permitted, since the building will equalize with its environment through the night, possibly aided by artificial circulation of outside air.

Load leveling
A plot of a typical day will indicate several peaks and spikes. A peak will show a gradual increase to maximum of, for example, the HVAC system as the building approaches the maximum load. Spikes may indicate the operation of the laundry or kitchen for an hour of intense activity, when copious quantities of hot water are used and generated rapidly, and electric equipment operates at high loading conditions.

The use of energy to complete the necessary daily functions at the facility cannot be avoided. However, the timing is often flexible. Instead of operating the laundry in the middle of the afternoon, for example, when the HVAC is approaching its peak, the laundry can be done earlier in the day. This will not affect the actual energy used, but it will reduce the peak load because the baseline is lower. The lower daily peak, in turn, will reduce the demand fee charged by the utility.

The ability to apply this principle of load leveling depends on a thorough understanding of the energy using equipment at a facility, plus knowledge of the daily routines that happen in every department. The best way for the engineering staff to attain this level of competence is to first document information on each major item of equipment, then follow an explicit maintenance program. Once a strong technical understanding is accomplished, then the facility management can be approached with the load leveling concept. If sufficient support is presented no doubt the decision will be made to reschedule certain activities to reduce the peak usage by shifting a part of the load to off peak hours.

Two stage controls
There are numerous applications for two levels of controls. One example is a large room served by two air handlers. Instead of having both controlled by a single thermostat (which will resort to short cycling and excess energy use) or controlled by separate thermostats, a single controller will activate one unit, then both, as the space load demands. Many manufacturers have programmable thermostats with this function built in, for control of two stage compressors.

Another common application for this simple device is to control a two speed motor of an air handler. The controlling function can be static pressure in the discharge duct to a variable air volume system. This is an inexpensive option to inlet vanes or a variable speed drive, and is a good compromise for system retrofits when the VFD is too costly. If the new two speed motor is a high efficiency model, there may be nearly as much savings as from installation of a VFD anyway, depending on the number of exterior and interior zones served by the air handler.

If an air handler serves only a few zones, then the two speed motor can be interlocked with a space temperature sensor; that is, if the air distribution is not overly affected at the new air flow rate for a constant volume system. An ideal application of this method is a system serving, for example, two operating rooms in a hospital or two classrooms in an academic building. If only one of the spaces is in use the air ducted to the other can be dampered off, the motor put on low speed and the system operates at half capacity to adequately condition the one room.

Save Water

2009-02-11T10:06:00.000+07:00

Save water

Did you know that water companies have to use energy to supply mains water to our homes? We then use more energy heating it up for baths, showers and washing up. Using energy means that carbon dioxide emissions will be generated, which contributes to climate change. The Energy Saving Trust is concerned about water waste and as an energy saver we think you should be too.

Each person in the UK currently uses about 150 litres of water every day, which has been rising by 1% a year since 1930 and much of this is wasted, disappearing down the plughole as we brush our teeth or being flushed down the toilet. For example, a dripping tap can waste as much as 5,500 litres of water a year, which is enough to fill a paddling pool every week for the whole summer. This consumption level is not sustainable in the long-term. If we do not take action now, climate change, population growth and increasing water demand mean the UK could face increased water stress in the future.

If we all made some simple and quick changes in our homes, we could save loads of water. Waterwise, the leading authority on water efficiency in the UK, has a list of top tips to help you start saving today.

Find out about water saving tips inside the home

Find out about water saving tips outside the home

The Water System

2009-02-04T00:09:00.002+07:00

Tips & Tricks

The Water System
The water distribution system in a building is usually ignored as a potential energy conservation resource. It is a deceptively simple system, though, with many practical ways to optimize. These techniques can be divided into two general categories: reducing the use of water and reducing the heat lost from hot water piping.

Inspect for leaks
A simple way to reduce water usage is to be alert for leaks in pipes, fittings, pumps and gauges in mechanical rooms and at headers throughout the building. Faucets and other restroom fittings are also important locations to inspect for fluid loss. Swift repair of these water leaks will prevent collateral damage to wood surfaces and furnishings, ceiling tiles and electrical equipment. The savings will occur in the water bill and in a lower sewage disposal fee as well.

Leaks that occur in closed systems can be even more expensive. Water circulating in the chilled water loop, the condenser water loop and the steam loop is usually chemically treated for corrosion and high hardness. Water lost from these systems loses valuable chemicals as well, which increases the treatment costs. In addition, the energy needed to heat or cool the circulating fluid will rise since a portion of the energy spent is lost with the leakage of hot or cold water.

Reduce hot water storage temperature
Whenever the water temperature at the point of use is too hot, copious quantities of cold water are needed to cool it to a satisfactory temperature. A slight reduction in hot water temperature will ensure it is delivered at the best temperature. Lowering the tank thermostat setting will also reduce the cost of keeping the water heated. A variation on this theme, called hot water reset, is practiced by large institutional users. A remote outside thermometer automatically increases the hot water supply temperature when the weather is warm. This can also be done by manually changing the setting at the beginning of the cooling season, then increasing it when the heating season begins.

More efficient operation of cleaning equipment
A good portion of the hot water used at an institutional building is devoted to washing dishes in the kitchen and washing clothes in the laundry. If the equipment used for these tasks does not have settings for different size loads then it is most efficient to operate them only when full. Use of an economizer cycle, if available, is another energy saver; for example, drip drying dishes naturally instead of with forced heat. Adjusting the settings to wash and rinse with the coldest practical water temperature will also save energy without sacrificing quality.

Reduce volume of waste disposal methods
Many commodes are now made with a smaller toilet flush tank to reduce the volume of water used with each cycle. The same principles have been applied in other appliances, for considerable savings. Such large users of water as clothes washers and dish washers benefit from water conserving practices, especially if the quantity of cleansers used are reduced so that less water is used in the rinse cycle.

Inspect and repair damaged insulation systems
Sagging or missing sections of insulation should be promptly attended, as they are not only an energy loser but may also indicate a leaking pipe in need of repair. If the insulation is worn because it covers a pipeline in a heavy use area the insulation should be replaced, then covered with a sheet metal sleeve to prevent future damage.

Install time clocks on water heaters
Most business offices are open during the daylight hours, Monday through Friday. Allowing for cleaning crews after hours, the time during which hot water is needed is perhaps sixty hours a week. The typical hot water heater is on all the time, 168 hours each week. A timer will greatly reduce this wasted energy. It can be set to turn on an hour of so before the beginning of the business day and still provide the same consistent service as though it were on constantly. Also, with extra down time, the heater will have a much longer useful life.

Insulate hot water heater(s) and storage tank(s)
Many utilities will provide water heater "blankets" at no cost. Others offer rebates to businesses and individuals who purchase high efficiency hot water heaters that have adequate insulation built into the unit. If the heater is located within the conditioned space, heat emanating from the unit will add to the load on the air conditioning equipment. If it is located outside - and is poorly insulated - much heat will be lost in the winter to the environs. In either case it is important to maximize insulation.

Install flow restrictors at hot water faucets and shower heads
This is another effective way to reduce water usage, while sacrificing little to convenience or necessity. To compliment such measures it is helpful to promulgate a general philosophy of water conservation, especially in the kitchen. People tend to think of water as an inexhaustible resource, not realizing the energy is saved by not wasting hot water.

Consider increasing pipe insulation thickness
Many older buildings were built at a time when energy was inexpensive. The hot water piping may not have been insulated at all, or it could be wrapped with a minimal thickness. A high quality product is available that is more efficient and durable. Pipe routed through unconditioned spaces such as the pipe basement or attic should not be without insulation.

Consider instantaneous heaters at remote locations
Several manufacturers offer small point of use instantaneous water heaters. If there are only a few locations in a building that require hotter water than the rest of the facility, these devices can help save energy - if the volume is low - by allowing the main hot water temperature to be reduced. This will reduce the thermal losses from the storage tank as well as from the loop piping.

Install a separate water heater for the kitchen or laundry
A sophisticated hot water system, in a hospital for example, will be designed to supply 180 degree F water to the kitchen and laundry and 120 degree F water everywhere else. Many buildings will simply supply the hotter water everywhere, at great waste - and sometimes great danger, from the scalding hot water.

Saving Energy in the Lighting

2009-02-01T10:20:00.001+07:00

Tips & Tricks

Saving Energy in the Lighting
A fourth of all electricity sold in the United States is used for lighting. Most of this lighting is used in stores, offices, warehouses and factories. It is strange, then, that conserving energy with lighting projects is not a high priority for most businesses. They assume lighting is a fixed overhead item that cannot be substantially reduced as an expense.

One mistake businesses make is to concentrate on first cost and purchase the cheapest lamps. They do not bother to consider the life cycle cost of these lamps. This can be a big mistake, given the 20,000 hour life of a typical fluorescent lamp. Installation of more efficient lamps can pay for their modest extra cost many times over. Industries that ignore this reduce their own competitiveness by operating under an escalating overhead, increasing with the electric rate.

Any modifications to the original lighting design at a facility should be done so that the quality of the lighting environment is not diminished. Exact illumination levels have been established to be maintained for specific tasks in the workplace. A number of inexpensive projects can be done, however, that do not significantly affect the light levels. They can be implemented by the maintenance staff, often without engineering design or approval required.

Use fluorescent lamps for interior lighting
Fluorescent lamps are much more efficient than incandescent lamps and should be used where possible, including task lighting and down lights. Compact fluorescent lamps are available that can be screwed directly into incandescent sockets. Thus they provide inexpensive lighting without sacrificing the convenience of incandescent lamps.

High intensity discharge (HID) lamps are more efficient than incandescent flood lights and should be used in their stead. HID lamps are best suited for large interior spaces with a high ceiling such as lobbies and atriums. They are also ideal for locations that are hard to access, such as mechanical rooms or auditorium with high ceilings. HID lamps have a longer lifetime than either fluorescent or incandescent bulbs and do not have to be changed as often. Incandescent light sources are still best for some applications, such as pipe basements, housekeeping closets and other areas with special requirements such as darkrooms, photo labs and studios. Limited use of incandescent lamps in conference rooms and dining areas that need lamps to be dimmed is common, although fluorescent dimming systems are becoming more competitive and commonplace.

Arrange fixtures to suit furniture arrangements
A general guideline for locating fixtures in a room that does not have fixed task locations is to position fixtures within 2 or 3 feet of walls. Then arrange fixtures in a regular pattern to provide a minimum light level, using task lighting at individual work stations.

If the work spaces are well defined or the location of furniture known a general lighting layout is not necessary. Instead, lights can be positioned directly above the work surface and located in non-task areas to provide a lower ambient light level. The latter include aisle space and such traffic locations as doorways. Lights should not be placed in the arc of a door swing as area lighting in the rest of the room will generally provide adequate illumination there.

These modifications to traditional lighting schemes are possible because the IES stipulates an ambient or average light level at the work surface. The zonal cavity calculation method generates this value in a space and when lighting designers specify fixtures according to these figures, the results can be deceptive. As an example, consider a common lighting design situation.

Two three lamp fixtures in a small office may produce a calculated light level of 60 footcandles, while the light measured directly beneath either fixture may be 120 or more at the desk top level. One of the fixtures can be eliminated entirely. There will still be good light at the work surface and adequate light in the rest of the space, where only 20 or 30 footcandles are needed. The only contingency to this scheme is to insure that the contrast is not excessive between the work surface and its environs. In small office with light colored walls this should not be a problem.

As another example consider a laboratory or shop with built in work tables and work benches. Adequate light can be provided by a row of fluorescent fixtures. They should be centered over the front edge of wall mounted tables and perpendicular to double sided tables in the middle of the room. Since fluorescent fixtures emit more light parallel to the axis of the lamps than crosswise so a solid row of lamps may not be necessary. Lights over open floor areas can be omitted altogether or reduced to provide a minimum level of light for contrast.

A final case is a large storage room. If the shelve locations are fixed then fixtures located lengthwise over the aisles will make the most efficient use of lighting. If the shelve locations are not well known then a good alternative is to run fixture rows at 45 degrees to the room dimensions.

In all of these cases a degree of flexibility can be built into the design, especially if a large floor space is to be illuminated. Each fixture can be wired with a few extra feet of flexible cable to permit shifting it in a variety of positions in the ceiling grid. They can even be wired with a quick disconnect cable so that fixtures can be moved from one space to another as the floor plan changes or lighting needs vary. This will cost a little extra up front. However, if the space usage is expected to change frequently this flexibility can save the cost of a complete rewiring job with each remodeling.

Limit decorative lighting
Lighting in special areas such as conference rooms, lobbies, auditoriums and waiting rooms should be kept simple and functional. Special treatment for architectural purposes should use efficient fluorescent or HID lamps and should, where possible, double as general illumination. Decorative lighting of the building exterior should only be done if it is incidental to a functional lighting system.

Control exterior and parking area lighting
Exterior lighting of walkways and building entrances can remain on during daylight hours or at other unnecessary times. If these lights are on a dedicated circuit they can be turned on and off independently by an electromechanical timeclock. Work hours do not always coincide with the hours of darkness. Often the exterior lights will burn when in is light out either before or after business hours. The time clock will automate this function and save the staff the trouble. It will have to be reset periodically, though, as the seasons pass. A photocell connected in series with the time will resolve this problem and further reduce the time the lights are in use.

Lighting for parking lots and parking garages will benefit from these controls as well, to insure the lights operate only when needed. Further savings are possible from circuiting the luminaires in logical groups that can be cycled on and off during the night. For example, a multi-level parking garage can leave only one level on during the off hours. This will work especially well for buildings with an integral garage. Such facilities often have only a single access door after close of business, so most parking will be near this entrance anyway. Parking lots can follow the same method, security needs notwithstanding.

Use separate work station switching
Large work spaces with individual work stations separated by partitions are common in laboratories and business offices. When a single person works late the entire space must be lit. An energy efficient alternative is to switch the lights so that one level will provide area lighting, then other switches at each logical work area will activate overhead lighting specific to that area.

Maximizing Use of Daylighting
Any room with outside windows has daylighting available to supplement the artificial luminaires. There are three types of daylight that can enter a conditioned space: direct, indirect and reflected. Direct light is the least desirable because it can cause problems from glare and it also has the highest contribution to the cooling load for a space. Reflected light can have similar consequences unless it is carefully controlled.

Some architectural features can be enhanced to increase the natural lighting available to a space. Reflective sills and properly angled venetian blinds can be used to amplify the flow of light through windows or opaque openings such as glass brick walls. Even directing the light straight up to a light colored ceiling will help, as the reflected light from this ceiling will reach deep into the room.

Landscape features are also helpful to direct more natural light through windows. A reflective area on the ground beneath a ground level window - of gravel, a light colored wood or concrete - will direct more diffuse light through nearby wall openings. Carefully trimming shrubs, trees and ground covering around windows will also help. These plantings may be desirable around windows facing south or west in the summer, however, to prevent direct light from heating up the building excessively in the late afternoon. Many people will trim the plants anyway and use blinds or shutters when direct lighting is a detriment.

The incentive for increasing natural lighting is that it is the best for color discrimination and detailed work such as drawing, painting or drafting. artificial lighting can be designed to approach the natural ideal, but no further. Consequently any method that can increase the natural light in a space will enhance the lighting environment, thereby improving the productivity and attitude of the people within.

Another factor of daylighting to consider is that windows with closed blinds or curtains have a higher insulation value. This is offset by the fact that the lights in a room also generate a portion of heat that must be removed by the air conditioning. This may be as much as ten percent of the total load. With the exception of direct lighting, though, it is generally an energy saver to take advantage of the daylight and pay the small penalty in higher air conditioning cost.

The electricity savings made possible by increased use of daylighting can take several forms. In a space that can turn off all lights when outside conditions are favorable, the total lighting cost can be considered the net savings. Even though the available natural light varies through the day and from season to season, the annual electricity savings could be as much as 60% of the lighting bill.

A final alternative is to put the lights in a daylit space on a multi-level switching system. If the space has three-lamp fluorescent fixtures, for example, the ballasts can be modified to permit one, two or three lamp operation of the lights for three separate ambient light levels. This provides the flexibility of supplementing the daylighting the minimum necessary to provide the proper total footcandle levels.

Each of these systems will permit immediate savings, depending on the type of controls used and the extent to which the present switching must be modified. The cost and payback calculations can be complex, and will be detailed in the forthcoming section on controls.

Reducing Illumination Levels
Use of task lighting can reduce the footcandle levels in a space and reduce the electrical energy demand by 20% - 50%. Good areas to consider for this M & O are large open office areas where each workstation has a desk lamp, such as an engineering office that provides each drafting table with a lamp. In such instances the overhead lighting is no longer used to provide a task-specific illuminance, but serves only to supplement local light sources at each desk.

Light levels can also be safely reduced in non-critical areas such as hallways, lobbies, waiting rooms, storerooms, mechanical rooms and restrooms. There are a number of ways to reduce the illumination levels. The best method to use depends on the type of lamps to be modified, incandescent or fluorescent. The energy saved will be in direct proportion to the reduction in wattage.

Project Strategy
It is important before beginning a major lighting retrofit project to first become familiar with the lighting environment of your business. Doing one or two of the M & O's is a good way to understand lighting and to become familiar with the equipment and technology.

A strong incentive, other than simple energy savings, concerns the effect of lighting on performance, accuracy, visual comfort and sometimes even morale and attitude. If your project is planned carefully and implemented properly not only will there result a savings in energy usage, but the working environment will be improved.

Home Energy Saving Tips

2009-01-11T11:16:00.000+07:00

Home Energy Saving Tips

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Here are some tips to help you save energy, save money and do your part for the environment.

Try these easy, low-cost or no-cost energy saving tips.

See how easy it is to save energy and money. Watch these energy saving tips featuring Shell Busey.

Furnace
		Keep your furnace clean, lubricated and properly adjusted with annual maintenance. If your furnace is working at peak efficiency it will use less energy and cost less to operate.
		Clean or replace the filter every 1-2 months - a dirty filter reduces the airflow and forces the furnace to run longer to heat your home.
		Consider purchasing a new ENERGY STAR® qualified furnace with a variable speed motor. An average home can save up to $650 in natural gas and electrical costs annually when upgrading from a standard 60% efficiency natural gas furnace to a 95% efficiency furnace with a high efficiency variable speed motor.
		Click here to see a video on how to change your furnace filter

Thermostat
		Lower your thermostat by 4 - 5 degrees Celsius (7 - 9 degrees Fahrenheit) while you're sleeping at night and when no one is at home.
		Install a programmable thermostat. You can save 2% on your heating bill for every 1 degree C you turn down your thermostat. With a programmable thermostat to consistently lower your heat when you don’t need it, you could save up to $92 a year!

Laundry
		Switch to cold when doing your laundry. 85 – 90% of the energy used to wash your clothes is used to heat the water. By turning the dial to cold on your washing machine, you help the environment, save energy, and save money.
		Wash full loads.
		Choose a front loading washing machine. Not only does a front loading washing machine save water, it saves energy as well. It uses about 40% less water and about 50% less energy.

Weather-stripping
		Weather-stripping provides a barrier between the fixed and movable sections of doors and windows. Apply weather-stripping to operable windows, exterior doors, garage doors, and doors that lead to the attic.
		Click here to see a video on how to apply weather-stripping to exterior doors

Windows, doorframes, sills and joints
		Apply a sealant or caulk around windows, doorframes, sills and joints. On a windy day feel for leaks or use a couple of incense sticks to help identify leaks around windows, electrical outlets, vents and exterior doors. As well look for spider webs - if there is a web there is a draft.
		Use plastic window covers to help prevent heat loss.
		Keep return air grills and heating vents clear of furniture, rugs and drapes, so there is no interference with the flow of heat through your home.
		Click here to see a video on how to apply caulking to windows and doors
		Click here to see a video on how to apply shrink film to windows

Basement
		If you have an unfinished basement or crawlspace, check for leaks by looking for spider webs. If there is a web, there is a draft. A large amount of heat is also lost from an un-insulated basement.
		Add insulation to basement walls.

Drapes & Blinds
		On sunny days, open south facing drapes and let the sun in, a natural source of heat. If you have large windows that don't receive direct sun, keep the drapes closed.
		Close your drapes and blinds during the night.

Pipes, ducts, fans and vents
		Plug gaps around pipes, ducts, fans and vents that go through walls, ceilings and floors from heated to unheated spaces.

Showerheads and faucets
		Install low-flow showerheads and faucets.
		Click here to see a video on how to install a low-flow showerhead
		Click here to see a video on how to install a Water Wizard ™

Dishwasher
		Always wash a full load in your dishwasher and air-dry your dishes on the “energy saver” setting.

Garage
		Turn on the heat just prior to use, save by not heating it continuously.

Wood Fireplace
		Close the damper to prevent warm air from escaping through the chimney, and ensure the damper fits properly.

Other
		Use the Equalized Payment Plan so you can average your bills and avoid peak winter bills.
		See what the big energy users in your home are and get suggestions for changes to save energy and money using energycheck, a quick an easy home energy audit found on the SaskEnergy website.
		For more energy savings tips visit the Office of Energy Efficiency, Natural Resources Canada website.

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http://www.saskenergy.com/saving_energy/tips.asp

Energy Saving Tips

2009-01-09T23:26:00.001+07:00

Tell Some Friends About This Page!

Energy-Saving Solutions for Your Home
Energy costs are reaching record highs, and heating and electricity bills are keeping pace. Luckily, there are steps you can take in your home to lower your heating and electricity bills.

Stop funneling money to coal-fired power plants

Tip # 1 - Purchase clean, renewable electricity!
Visit green-e.org to find out if you can switch from purchasing electricity from CO2-spewing coal-fired power plants to clean, renewable energy sources.

Smarter Lighting: A Bright Idea
One of the easiest and cheapest places to start saving energy is with lighting.

Tip #2 -- Replace your most frequently used incandescent bulbs with compact fluorescent lights.
Compact fluorescent light bulbs use only a third as much electricity as a standard incandescent bulb. Because a compact fluorescent will usually last ten times as long as a regular bulb, which means it is will easily pay for itself. If every household in the U.S. replaced one light bulb with a compact fluorescent light bulb (CFL), it would prevent enough pollution to equal the removal of one million cars from the road.

Tip #3 -- Replace outdoor lighting with a motion-detector equipped bulb or fixture.
Outdoor lights that are left on all night can add unnecessary waste energy and disturb wildlife. You can safely and efficiently light the outside of your home by installing light fixtures that are activated by motion sensor or a timer. These devices will keep areas well lit when you need them to be while reducing your energy bill

Hot Water shouldn't be a drain on your wallet.
Over 10% of your energy bill goes to heating water for your dishwasher, shower, and faucets. You can cut this energy use, and your energy bill, by implementing these easy steps.

Tip #4 -- Lower your hot water heater to 120 degrees and drain any sediment.
Though you need to keep your water heater above 120 degrees to prevent bacteria from building up, many hot water heaters are set too high. Draining some water a few times a year reduces sediment and increases efficiency.

Tip #5 -- Add insulation to your hot-water heater.
The standard hot water heater is on all the time, adding extra insulation will save more energy than you think. Most hardware stores sell pre-made insulator "jackets" that can be easily wrapped around one's water heater. Adding insulation to your water heater and any exposed pipes can knock up to 15 percent off the costs of heating water.

Tip #6 -- Install a low-flow shower head.
Low-flow shower heads are also a worthwhile investment (especially for renters, because you can take them with you) that will reduce the amount of hot water you use and hence the energy needed to heat it.

Heat your home - Not the planet.
Heating and cooling your home is the single largest expense on your energy bills. But taking steps to weatherize your home, you can make keeping your home a comfortable temperature easier and cheaper.

Tip #7 -- Check for and seal any cracks or gaps.
Heating one's home is the single largest use of energy for the average customer. Tiny gaps and cracks in an older home are roughly equivalent to a one-foot square hole punched in your wall, which means that sealing gaps with caulking and weather stripping makes a big difference in keeping the heat inside your home and saves you money.

Tip #8 -- Tighten Windows and Loosen Your Budget
If all windows were as efficient as the best products now widely available in the marketplace, the average household would save $150 a year, and reduce its carbon dioxide emissions by about 4,300 pounds per year. A cheaper and easier method than replacing windows is to insulate your windows during the colder months with transparent film that keeps the heat in and the cold out.

Tip #9 -- Heating Ducts: Keep the air flowing
If just one in ten households used current technology to upgrade their inefficient heating systems, we could keep 17 billion pounds of pollution out of the air. You can also save money and cut pollution by having your heating vents and ducts cleaned regularly, and having your furnace serviced.

Tip # 10 - Sweaters are in this season, so lower your thermostat!
Besides insulation, you can make a big difference in your heating bill by keeping your home at a slightly lower temperature. Lowering your thermostat one degree can cut as much as 10% of your heating bill.

Appliances and Electronics

Tip # 11 -- Replace old appliances with more efficient models.
Though buying a new appliance isn't cheap, replacing an old appliance, like a refrigerator, washing machine, or furnace -- with a new, energy-efficient model can significantly cut your energy bill. Look for the Energy Star label as a minimum; some models can be even more efficient. And though buying a new appliance is a major investment, many states and utility companies offer substantial credits or other incentives to replace an outdated appliance with a more efficient one.

Tip # 12 Defrost your Freezer
The frost and ice that builds up in your freezer over time does more than make it hard to get to your ice cream - it also causes your freezer to work harder to keep the freezer at a cold temperature. By routinely defrosting your freezer, you can keep your ice cream cold and the planet cool.

Tip # 13 - Dirty Clothes, Clean Planet
Modern washing machines and detergents can clean clothes effectively in cold water - which means you don't have to waste energy by using hot water. Another way you can save energy in your washer-dryer and your dishwasher is to always wash full loads.

http://www.sierraclub.org/

The History of Wind Energy

2009-01-08T00:02:00.003+07:00

History.
By Emil Bedi, CANCEEand Hakan Falk, "Energy Saving Now".

Wind has been used by humankind as a natural source of energy for tens of thousands of years. The use of wind energy dates back to the dawn of civilisation when sailing vessels were powered by the wind. The first simple sailboats were set afloat in Egypt about 5,000 years ago. Around the year 700 AD, in what is Afghanistan today, the first wind machines rotating around a vertical axis were employed to grind grain. The famous fixed-tower windmills with sails provided irrigation for many parts of the Mediterranean island of Crete. Wind-driven gristmills were one of the greatest technical challenges of the Middle Ages. In the 14th century, the Dutch improved on the design that had spread throughout the Middle East and continued to use it for its primary purpose of grinding grain.
A wind powered water pump was introduced in the United States in 1854. It was the familiar fan type with many vanes around a wheel and a tail to keep it pointed into the wind. By 1940, over 6 million of these windmills were being used in the United States mainly for pumping water and generating electricity. The “Wild West” was won at least in part with the help of these wind pumps that were used to supply water for the massive herds of cattle.
However, the 20th century soon brought an end to the widespread use of wind energy, which gave way to the “modern” energy resources, oil and electricity. It was not until after the oil crisis that wind energy options met with renewed interest. As a result of the drastic rises in oil prices at the beginning of the 1970s, energy planners have once again been turning their attention increasingly to the utilization of wind energy. State-sponsored research and development grants in many countries have provided a fresh stimulus to the development of technology for the utilization of wind energy. Efforts have been concentrated on developing wind energy converters for generating electricity, because in the industrialized countries the application of wind pumps is of minor importance.

USA
The oil embargo of 1973 was the driving force behind wind turbine development programs in the United States. Westinghouse Electric developed first generation of 200 kW wind turbines, known as MOD-OAs. The largest of this series and the largest in the world, the 3,2 MW MOD-5B is operating in Oahu, Hawaii. The Public Utilities Regulatory Policies Act (PURPA) of 1978 and a 25% tax credit for investors in turbines jump started commercial development of the United States wind industry and resulted in 6870 turbines being installed in California between 1981 and 1984. The tax credits expired on Dec. 31, 1985. None of the small wind turbine companies, however, were owned by large companies committed to long term market development, so when the federal tax credits expired and oil prices dropped to USD 10 a barrel, most of the small wind turbine industry once again disappeared. The companies that survived this “market adjustment” and are producing small wind turbines today are those whose machines were the most reliable and whose reputations were the best. Nevertheless the year 1998 showed that the interest in wind energy is back again.

DENMARK
Denmark’s wind energy industry is a major commercial success story. From standing start in the 1980 to a turnover of 1 billion USD in 1998. Danish wind turbines dominate the global market. From a few hundred workers in 1981 the industry now employs 15000 people. Its turnover is twice as large as the value of Denmark’s North Sea gas production. Output , mainly for export around the world, has increased to 1216 MW of capacity in 1998. Now over half of the wind turbine capacity installed globally is of Danish origin.

The Danish government introduced support for renewable energy technology in 1979, covering 30% of capital cost. State aid encouraged the development of a highly successful wind turbine industry (it has also been used to promote the use of straw, biogas and solar projects).Danish wind turbine manufacturers were advised on ways of improving the performance and reducing costs of their machines by experts based at the National Wind Turbine Test Centre at Riso. The grants for wind turbines were reduced to 15% in 1986and finally phased out all together in 1989 as the industry became established. They have since been replaced by tax credits – the owners of wind turbines obtain a proportion of the income from the sale of electricity tax free.

Huge wind power development In Denmark was mainly based on activity of local people organised in co-operatives. Here is one example from Bryrup Wind turbine Co-operative (Jutland), 110 km from the West-coast and 50 km from the Eastern coastline. This co-operative has 70 partners owning three wind turbines installed between 1986 and ‘89. The effects is as follows: one 95 kW producing 184 000 kWh a year and two 150 kW each producing 275,000 kWh. Thus average total production amounts to 734 000 kWh annually.
Total price for all three turbines including foundation and connection to the public grid amounted to 2,5 million DKr (1 USD equals 6.2 DKr). This investment is split up in 734 “shares!’, each related to a production (and a consumption) of 1000 kWh, at a cost of 3,400 DKr. This equals half a month salary after tax for an unskilled Danish worker. Each partner can buy “shares” in proportion to his annual consumption of electricity plus 30%. If for instance annual consumption is 10 000 kWh you may add 3 000 kWh and thus be able to acquire maximum 13 “shares”. This restriction is applied because the profit for co-operative partners is tax- free, and the Danish legislators did not wanted this profit to be unreasonable. The partners have bought an amount of “shares” at numbers between 1 and 28. At the democratic general assemblies each partner has one vote despite numbers of “shares”. The reason for putting shares in quotation marks is related to the fact that these “shares” can not be traded like normal shares. By coming sales, buyers must apply to the rules referring to electricity consumption.
The economy of this co-operative is good. They distribute every year - after putting aside a reasonable amount for maintenance and renewals - 510 DKr per “share”, which gives a tax-free Interest rate of 15% what is more than banks can offer for your money. Today installation of wind turbines is a bit more costly. A share will amount to 4000 DKr, thus reducing interest rate to 12,75%.
The Danish governmental support for wind power has caused that every tenth Danish family is member of a wind turbine co-operative or single owner of a wind turbine.

GERMANY
In contrast to the situation in Denmark or California, where a large number of wind generators were installed early on, the revival in Germany was relatively late in coming. In 1989, the German Federal Government initiated a promotion programme which called for the installation of wind generators with a total capacity of 250 MW over the next seven years. German utilities are legally obliged to credit 90% of the standard rate charged to their customers for the wind-generated electricity supplied to the public power mains by any operator. This currently corresponds to a value of DM 0.17/KWh (US$ 0.11/KWh). This programme has led to a rapid increase in the number of installations and today Germany is leading country in installed wind power capacity.

DEVELOPMENT
Windpower has retained its status as the fastest growing energy source in the world. Until the year 1998 wind turbines with a total generating capacity of over 9500 megawatts have been built around the world and they generated enough power for about 3,5 million homes.

Country	Installed capacity in MW End of 1998	Increase of capacity (1997-98)
Germany	2875	36,4 %
USA	2141	9,9 %
Denmark	1420	30,6 %
India	992	19,9 %
Spain	880	87,7 %
Netherlands	379	15,0 %
UK	338	19,1 %
China	200	65,6 %
WORLD	9597	27 %

In Europe, over 1600 MW was constructed in the year 1998 and energy analysts now consider that by the year 2010 almost 40.000 MW can be installed around the continent. Germany led the way in 1998, with a record 793 MW of wind schemes going up. This brought the country’s total to an impressive 2875 MW, producing as much electricity as two of the country’s largest coal-fired power stations. The average size of turbine increased by 150 kW to 785 kW. Spain also boomed, with 256 MW of new installations contributing to a total of 707 MW. It is estimated that 23% of electricity in the northern Spanish province of Navarra is now provided by the wind. Denmark was equally active, with 300 MW installed. The United States was the other flourishing market, its revived activity bringing a further 235 MW on line. Worldwatch Institute values the sales of wind turbines globally in the year 1998 at roughly USD 2 billion. It says that larger turbines, more efficient manufacturing and careful siting have brought wind power costs down from USD 2600 per kilowatt in 1981 to USD 800 in 1998. The institute expected at least an additional 2500 MW to be installed world-wide during 1999. The reality seems much better because until the end of June 1999 more than 2000 MW were added to the total capacity.

Year	Megawatts in World	Megawatts in Europe
1980	10	-
1985	1020	80
1990	1930	475
1995	4820	2531
1998	9597	6030

The cost of wind power continued to decline through advancements in design, siting practices and the cost of capital from around 14 US cents per kWh in 1986 to below 5 cents per kWh in 1999. Wind power is now cost-competitive in many electric power applications and that is why it is experiencing rapidly growing deployment.
Over the past two years wind energy capacity has been expanding at an annual rate of more than 30%. In contrast, the nuclear industry is growing at a rate of less than 1% whilst coal has not grown at all in the 1990’s. Europe is the centre of this young and high-tech industry. 90% of the world’s manufacturers of medium and large wind turbines are European.

Wind capacity in end of June1999 (MW).

Germany	3390,6
USA	2532,8
Denmark	1581,3
Spain	1100
India	1013,2
The Netherlands	374
UK	344
China	246
Italy	222
Sweden	187
WORLD	11612

POTENTIAL
On current expectations, wind power is expected to grow at an annual rate of 20 % between 1998 and 2003, resulting in a total of 33 400 MW of installed capacity around the world by the end of that period. According to recent study “Wind Force 10” wind power could generate 10 % of global electricity by 2020, and create 1,7 million jobs at the same time. International installation of 1,2 million MW of wind capacity by 2020 would generate more electricity than the entire continent of Europe consumes today. Total wind energy potential in the world is 53 trillion kWh, 17 times higher than the Wind Force 10 goal. According to the study the cost of generating electricity with wind turbines is expected to drop to 2.5 US cents/kWh by 2020, compared to the current 4.7 US cents/kWh.
Environmental benefits of the 10 % target would be enormous – savings of 69 million tonnes of CO2 in 2005, 267 millions tons in 2010 and 1780 million tonnes in 2020.

JOBS
Renewable energy has become an important employer. There are over 110.000 jobs in the manufacture, installation and maintenance of renewable energy technologies in the European Union. Wind energy accounts for around 20% of this. Most of the 700 companies involved are small and medium sized enterprises. As the industry grows, so more jobs are created. At the end of 1996 more than 20.000 Europeans were estimated to be employed in wind energy, and this figure is projected to grow to 40.000 by the year 2000.

Markets

Wind power systems are being built all over the world. They are ideally suited to the needs of developing countries, which urgently need new capacity. They can be brought on line relatively cheaply and quickly in comparison with large power stations, which need major electrical infrastructure and grid systems to transmit their power. Developed countries are also a key growth area as they turn to wind power for environmental and economic reasons. Wind energy can be integrated into existing electrical systems, reducing the amount of power which needs to be generated by burning fossil fuels.

SOCIAL PROBLEMS RELATED TO ENERGY USE

2009-01-05T01:28:00.005+07:00

By Emil Bedi, CANCEE and Hakan Falk, "Energy Saving Now".

Beside environmental problems associated with large-scale use of fossil and nuclear fuels and the problems with sustainability there are also social problems arising from present trends of energy utilization.

Political and economic problems

In the earlier stages of the industrial revolution, fuel sources were local and widely distributed. Industrial activity tended to grow in areas where local sources of coal were available. As the transport associated with industrialisation spread and developed, fuels began to be transported from more and more distant places. Now, with the most accessible sources of oil and gas depleted, fuels are transported around the world from small number of major producing areas. The result is that the major industrial nations have become dependent upon supplies from those producing nations, in particular oil from the Middle East, and are highly vulnerable to disruption of these supplies. This vulnerability and dependence has been a major factor shaping world politics. A series of major economic and political crises has resulted from Sues crisis in 1956 to the 1970s, oil crisis to the Gulf war in early 1990s. Since the producing nations are generally weak militarily and the consuming nations are generally stronger, latter are under pressure to dominate the former economically, politically and if necessary, militarily to maintain access to oil (most important fuel today).

Oil price depends on political situation and each conflict in oil sensitive region leads to higher energy prices. World economy is thus shaped with such conflicts.

VULNERABILITY DUE TO CENTRALISATION

A related aspect of vulnerability in the present form of industrialisation is the centralized nature of fuel production and distribution. Electricity is generated in relatively few, very large power stations, and distributed through the country. Oil is imported in giant tankers, and converted to fuel in large refineries for further distribution. Concerns have been expressed that these large, vital installations offer potential target for terrorists or military opponents. As has been seen in recent years in the Middle East (Gulf War), the result can be massive ecological damage as well as economic devastation. The normal response to such vulnerability is to put greater resources into security and to increased level of protection. High level of centralisation leads also to problems with employment. Decentralized energy production and utilization which is the case of renewable energy sources can create much more new jobs than centralized fossil fuel installations.

MILITARY DANGERS FROM NUCLEAR PROLIFERATION

Nuclear weapon proliferation is one of the biggest threat to the world peace today with several countries already in or trying to be a member of “nuclear club”. In developed countries nuclear electricity industries grew out of nuclear weapons development. The earliest nuclear reactors were built to produce material for nuclear bombs. There has always been a close connection between the two terms of the technology used, so that military spending on research and development for nuclear weapons technology has in effect been a major subsidy for civilian nuclear electricity industries. Nuclear fuel is not directly useful for nuclear weapons. Much further processing is needed. However, for a country wishing to develop nuclear weapons without publicly revealing the fact, an obvious approach would seem to be combine weapons development with a nuclear electricity generation industry.

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Energy Conservation

2008-12-23T10:51:00.001+07:00

Energy conservation

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This article is about decreasing energy consumption. For the law of conservation of energy in physics, see Conservation of energy.

Energy conservation is the practice of decreasing the quantity of energy used. It may be achieved through efficient energy use, in which case energy use is decreased while achieving a similar outcome, or by reduced consumption of energy services. Energy conservation may result in increase of financial capital, environmental value, national security, personal security, and human comfort. Individuals and organizations that are direct consumers of energy may want to conserve energy in order to reduce energy costs and promote economic security. Industrial and commercial users may want to increase efficiency and thus maximize profit.

Introduction

Electrical energy conservation is an important element of energy policy. Energy conservation reduces the energy consumption and energy demand per capita, and thus offsets the growth in energy supply needed to keep up with population growth. This reduces the rise in energy costs, and can reduce the need for new power plants, and energy imports. The reduced energy demand can provide more flexibility in choosing the most preferred methods of energy production.

By reducing emissions, energy conservation is an important part of lessening climate change. Energy conservation facilitates the replacement of non-renewable resources with renewable energy. Energy conservation is often the most economical solution to energy shortages, and is a more environmentally benign alternative to increased energy production.

[edit] By country

[edit] United States

The examples and perspective in this article may not represent a worldwide view of the subject.
Please improve this article or discuss the issue on the talk page. (August 2008)

The United States is currently the largest single consumer of energy. The U.S. Department of Energy categorizes national energy use in four broad sectors: transportation, residential, commercial, and industrial.^[1]

U.S. Energy Flow Trends - 2002. Note that the breakdown of useful and waste energy in each sector (yellow vs. grey) is estimated arbitrarily and is not based on data.

Energy usage in transportation and residential sectors (about half of U.S. energy consumption) is largely controlled by individual domestic consumers. Commercial and industrial energy expenditures are determined by businesses entities and other facility managers. National energy policy has a significant effect on energy usage across all four sectors.

[edit] Transportation

The transportation includes all vehicles used for personal or freight transportation. Of the energy used in this sector, approximately 65% is consumed by gasoline-powered vehicles, primarily personally owned. Diesel-powered transport (trains, merchant ships, heavy trucks, etc.) consumes about 20%, and air traffic consumes most of the remaining 15%.^[2]

The two oil supply crisis of the 1970s spurred the creation, in 1975, of the federal Corporate Average Fuel Economy (CAFE) program, which required auto manufacturers to meet progressively higher fleet fuel economy targets. The next decade saw dramatic improvements in fuel economy, mostly the result of reductions in vehicle size and weight which originated in the late 1970s, along with the transition to front wheel drive. These gains eroded somewhat after 1990 due to the growing popularity of sport utility vehicles, pickup trucks and minivans, which fall under the more lenient "light truck" CAFE standard.

In addition to the CAFE program, the U.S. government has tried to encourage better vehicle efficiency through tax policy. Since 2002, taxpayers have been eligible for income tax credits for gas/electric hybrid vehicles. A "gas-guzzler" tax has been assessed on manufacturers since 1978 for cars with exceptionally poor fuel economy. While this tax remains in effect, it currently generates very little revenue as overall fuel economy has improved. The gas-guzzler tax ended the reign of large cubic-inched engines from the musclecar era.

Another focus in gasoline conservation is reducing the number of miles driven. An estimated 40% of American automobile use is associated with daily commuting. Many urban areas offer subsidized public transportation to reduce commuting traffic, and encourage carpooling by providing designated high-occupancy vehicle lanes and lower tolls for cars with multiple riders. In recent years telecommuting has also become a viable alternative to commuting for some jobs, but in 2003 only 3.5% of workers were telecommuters. Ironically, hundreds of thousands of American and European workers have been replaced by workers in Asia who telecommute from thousands of miles away.

Fuel economy-maximizing behaviors also help reduce fuel consumption. Among the most effective are moderate (as opposed to aggressive) driving, driving at lower speeds, using cruise control, and turning off a vehicle's engine at stops rather than idling. A vehicle's gas mileage decreases rapidly highway speeds, normally above 55 miles per hour (though the exact number varies by vehicle). This is because aerodynamic forces are proportionally related to the square of an object's speed (when the speed is doubled, drag quadruples). According to the U.S. Department of Energy (DOE), as a rule of thumb, each 5 mph (8.0 km/h) you drive over 60 mph (97 km/h) is similar to paying an additional $0.30 per gallon for gas ^[3] The exact speed at which a vehicle achieves it's highest efficiency varies based on the vehicle's drag coefficient, frontal area, surrounding air speed, and the efficiency and gearing of a vehicle's drive train and transmission.

[edit] Residential sector

The residential sector refers to all private residences, including single-family homes, apartments, manufactured homes and dormitories. Energy use in this sector varies significantly across the country, due to regional climate differences and different regulation. On average, about half of the energy used in U.S. homes is expended on space conditioning (i.e. heating and cooling).

The efficiency of furnaces and air conditioners has increased steadily since the energy crises of the 1970s. The 1987 National Appliance Energy Conservation Act authorized the Department of Energy to set minimum efficiency standards for space conditioning equipment and other appliances each year, based on what is "technologically feasible and economically justified". Beyond these minimum standards, the Environmental Protection Agency awards the Energy Star designation to appliances that exceed industry efficiency averages by an EPA-specified percentage.

Despite technological improvements, many American lifestyle changes have put higher demands on heating and cooling resources. The average size of homes built in the United States has increased significantly, from 1,500 sq ft (140 m²) in 1970 to 2,300 sq ft (210 m²) in 2005. The single-person household has become more common, as has central air conditioning: 23% of households had central air conditioning in 1978, that figure rose to 55% by 2001.

As furnace efficiency gets higher, there is limited room for improvement--efficiencies above 85% are now common. However, improving the building envelope through better or more insulation, advanced windows, etc., can allow larger improvements. The passive house approach produces superinsulated buildings that approach zero net energy consumption. Improving the building envelope can also be cheaper than replacing a furnace or air conditioner.

Even lower cost improvements include weatherization, which is frequently subsidized by utilities or state/federal tax credits, as are programmable thermostats. Consumers have also been urged to adopt a wider indoor temperature range (e.g. 65 °F (18 °C) in the winter, 80 °F (27 °C) in the summer).

One underutilized, but potentially very powerful means to reduce household energy consumption is to provide real-time feedback to homeowners so they can effectively alter their energy using behavior. Recently, low cost energy feedback displays, such as The Energy Detective or wattson [1], have become available. A study of a similar device deployed in 500 Ontario homes by Hydro One [2] showed an average 6.5% drop in total electricity use when compared with a similarly sized control group.

Standby power used by consumer electronics and appliances while they are turned off accounts for an estimated 5 to 10% of household electricity consumption, adding an estimated $3 billion to annual energy costs in the USA. "In the average home, 75% of the electricity used to power home electronics is consumed while the products are turned off." [3]

[edit] Home energy consumption averages

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How to reduce energy usage

Home heating systems, 30.7%
Water heating, 13.5%
Home cooling systems, 11.5%
Lighting, 10.3%
Refrigerators and freezers, 8.2%
Home electronics, 7.2%
Clothing and dish washers, 5.6% (includes clothes dryers, does not include hot water)
Cooking, 4.7%
Computers, 0.9%
Other, 4.1% (includes small electrics, heating elements, motors, pool and hot tub heaters, outdoor grills, and natural gas outdoor lighting)
Non end-user energy expenditure, 3.3%^[4]

Energy usage in some homes may vary widely from these averages. For example, milder regions such as the southern U.S. and Pacific coast of the USA need far less energy for space conditioning than New York City or Chicago. On the other hand, air conditioning energy use can be quite high in hot-arid regions (Southwest) and hot-humid zones (Southeast) In milder climates such as San Diego, lighting energy may easily consume up to 40% of total energy. Certain appliances such as a waterbed, hot tub, or pre-1990 refrigerator use significant amounts of electricity. However, recent trends in home entertainment equipment can make a large difference in household energy use. For instance a 50" LCD television (average on-time= 6 hours a day) may draw 300 Watts less than a similarly sized plasma system. In most residences no single appliance dominates, and any conservation efforts must be directed to numerous areas in order to achieve substantial energy savings. However, Ground, Air and Water Source Heat Pump systems are the more energy efficient, environmentally clean, and cost-effective space conditioning and domestic hot water systems available (Environmental Protection Agency), and can achieve reductions in energy consumptions of up to 69%.

[edit] Best building practices

Current best practices in building design, construction and retrofitting result in homes that are profoundly more energy conserving than average new homes. This includes insulation and energy-efficient windows and lighting ^[5]. See Passive house, Superinsulation, Self-sufficient homes, Zero energy building, Earthship, MIT Design Advisor, Energy Conservation Code for Indian Commercial Buildings.

Smart ways to construct homes such that minimal resources are used to cooling and heating the house in summer and winter respectively can significantly reduce energy costs.

[edit] Commercial sector

The commercial sector consists of retail stores, offices (business and government), restaurants, schools and other workplaces. Energy in this sector has the same basic end uses as the residential sector, in slightly different proportions. Space conditioning is again the single biggest consumption area, but it represents only about 30% of the energy use of commercial buildings. Lighting, at 25%, plays a much larger role than it does in the residential sector.^[6] Lighting is also generally the most wasteful component of commercial use. A number of case studies indicate that more efficient lighting and elimination of over-illumination can reduce lighting energy by approximately fifty percent in many commercial buildings.

Commercial buildings can greatly increase energy efficiency by thoughtful design, with today's building stock being very poor examples of the potential of systematic (not expensive) energy efficient design (Steffy, 1997). Commercial buildings often have professional management, allowing centralized control and coordination of energy conservation efforts. As a result, fluorescent lighting (about four times as efficient as incandescent) is the standard for most commercial space, although it may produce certain adverse health effects.^[7]^[8]^[9]^[10] Potential health concerns can be mitigated by using newer fixtures with electronic ballasts rather than older magenetic ballasts. As most buildings have consistent hours of operation, programmed thermostats and lighting controls are common. However, too many companies believe that merely having a computer controlled Building automation system guarantees energy efficiency. As an example one large company in Northern California boasted that it was confident its state of the art system had optimized space heating. A more careful analysis by Lumina Technologies showed the system had been given programming instructions to maintain constant 24 hour temperatures in the entire building complex. This instruction caused the injection of nighttime heat into vacant buildings when the daytime summer temperatures would often exceed 90 °F (32 °C). This mis-programming was costing the company over $130,000 per year in wasted energy (Lumina Technologies, 1997). Many corporations and governments also require the Energy Star rating for any new equipment purchased for their buildings.

Solar heat loading through standard window designs usually leads to high demand for air conditioning in summer months. An example of building design overcoming this excessive heat loading is the Dakin Building in Brisbane, California, where fenestration was designed to achieve an angle with respect to sun incidence to allow maximum reflection of solar heat; this design also assisted in reducing interior over-illumination to enhance worker efficiency and comfort.

Recent advances include use of occupancy sensors to turn off lights when spaces are unoccupied, and photosensors to dim or turn off electric lighting when natural light is available. In air conditioning systems, overall equipment efficiencies have increased as energy codes and consumer information have begun to emphasise year round performance rather than just efficiency ratings at maximum output. Controllers that automatically vary the speeds of fans, pumps, and compressors have radically improved part-load performance of those devices. For space or water heating, electric heat pumps consume roughly half the energy required by electric resistance heaters. Natural gas heating efficiencies have improved through use of condensing furnaces and boilers, in which the water vapor in the flue gas is cooled to liquid form before it is discharged, allowing the heat of condensation to be used. In buildings where high levels of outside air are required, heat exchangers can capture heat from the exhaust air to preheat incoming supply air.

[edit] Industrial sector

The industrial sector represents all production and processing of goods, including manufacturing, construction, farming, water management and mining. Increasing costs have forced energy-intensive industries to make substantial efficiency improvements in the past 30 years. For example, the energy used to produce steel and paper products has been cut 40% in that time frame, while petroleum/aluminum refining and cement production have reduced their usage by about 25%. These reductions are largely the result of recycling waste material and the use of cogeneration equipment for electricity and heating.

Another example for efficiency improvements is the use of products made of High temperature insulation wool (HTIW) which enables predominantly industrial users to operate thermal treatment plants at temperatures between 800 and 1400°C. In these high-temperature applications, the consumption of primary energy and the associated CO₂ emissions can be reduced by up to 50% compared with old fashioned industrial installations. The application of products made of High temperature insulation Wool is becoming increasingly important against the background of the currently dramatic rising cost of energy.

The energy required for delivery and treatment of fresh water often constitutes a significant percentage of a region's electricity and natural gas usage (an estimated 20% of California's total energy use is water-related.^[11]) In light of this, some local governments have worked toward a more integrated approach to energy and water conservation efforts.

To conserve energy, some industries have begun using solar panels to heat their water.^{[citation needed]}

Unlike the other sectors, total energy use in the industrial sector has declined in the last decade. While this is partly due to conservation efforts, it's also a reflection of the growing trend for U.S. companies to move manufacturing operations overseas.

[edit] United Kingdom

Main article: Energy use and conservation in the United Kingdom

Energy conservation in the United Kingdom has been receiving increased attention over recent years. Key factors behind this are the Government's commitment to reducing carbon emissions, the projected 'energy gap' in UK electricity generation, and the increasing reliance on imports to meet national energy needs. Domestic housing and road transport are currently the two biggest problem areas.

The UK Government has jointly funded the Energy Saving Trust to promote energy conservation at a consumer, business and community level since 1993.

[edit] Jevons paradox

Main article: Jevons paradox

Standard economic theory suggests that technological improvements that increase energy efficiency will tend to increase, rather than reduce energy use. This was first observed by William Stanley Jevons in 1865 and is called the Jevons Paradox. In The Coal Question, Jevons argued that, "It is a confusion of ideas to suppose that economical use of fuel is equivalent to diminished consumption. The very contrary is the truth."

The Jevons paradox was later revisited by the economists Daniel Khazzoom and Leonard Brookes in a series of papers about energy conservation. In 1992, the US economist Harry Saunders dubbed this hypothesis the Khazzoom-Brookes Postulate, and showed that it was true under a wide range of assumptions.^[12] Increased energy efficiency tends to increase energy consumption by two means. Firstly, increased energy efficiency makes the use of energy relatively cheaper, thus encouraging increased use. Secondly, increased energy efficiency leads to increased economic growth, which pulls up energy use in the whole economy.

This does not imply that increased fuel efficiency is worthless. Increased fuel efficiency enables greater production and a higher quality of life. For example, a more efficient steam engine allowed the cheaper transport of goods and people that contributed to the Industrial Revolution. However, energy conservation cannot be achieved through increased efficiency alone. In order for efficiency gains to improve energy conservation, the ecological economists Mathias Wackernagel and William Rees suggest that cost savings from efficiency gains be "taxed away or otherwise removed from further economic circulation. Preferably they should be captured for reinvestment in natural capital rehabilitation."^[13]

[edit] Issues with energy conservation

This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (October 2008)

Critics and advocates of some forms of energy conservation make the following arguments:

It may be difficult for home owners or small business to justify investment in some energy saving measures. Often the available money has higher priorities, and in many cases the time and cost investment is not worthwhile.

Condensing boilers are much more efficient than older types. Energy savings are achieved by extracting more heat, venting less heat externally. However the increased complexity results in more frequent breakdowns and much higher total servicing costs, and whether the end result is a gain is debated.

Refrigeration is also a major factor of energy consumption, electronic Energy saving modules (ESM) can be added to some existing HVAC and refrigeration systems at little cost to conserve electricity.

Some retailers argue that bright lighting stimulates purchasing. Health studies have demonstrated that headache, stress, blood pressure, fatigue and worker error all generally increase with the common over-illumination present in many workplace and retail settings (Davis, 2001), (Bain, 1997). It has been shown that natural daylighting increases productivity levels of workers, while reducing energy consumption.^[14] Consumers are also motivated by a number of factors, and corporate stewardship may provide an incentive for shoppers to visit stores who conserve energy. Some believe lower overhead costs may allow retailers to lower prices, stimulating consumption, however few business managers seem to agree with this view.

The use of telecommuting by major corporations is a significant opportunity to conserve energy, as many Americans now work in service jobs that enable them to work from home instead of commuting to work each day. ^[15]

Electric motors consume more than 60% of all electrical energy generated and are responsible for the loss of 10 to 20% of all electricity converted into mechanical energy. ^[16] No doubt, electricity consumption and associated loss by electric motors will continually grow; particularly, as the transportation sector moves to vehicles with electric drivetrains. Migrating or retrofitting any applied base of electric motors (and electric generators) with energy efficient electric motor and generator technology and systems, such as the brushless wound rotor doubly fed electric motor or generator, can dramatically reduce energy consumption and resulting emissions of carbon dioxide (CO2) and sulphur dioxide (SO2) to the atmosphere. As a bonus, the technology can have a payback period of less than a year depending on use factors.

Zero Carbon Homes

2008-12-11T23:32:00.002+07:00

With green issues high on the agenda this year there’s a lot being talked about and introduced to tackle one of the biggest contributors of climate change – our homes. With 27% of the UK’s overall CO2 emissions coming from our homes, reducing energy in this area of our lives is essential. Going ‘zero carbon’ in the home is one of the new terms that have been debated, in parliament and throughout the housing industry. It sounds impressive, if a little too good to be true – so what is zero carbon all about?

What Does Zero Carbon Mean?

Put simply, a zero carbon home uses less energy than it generates over a set period of time. A carbon footprint is calculated for the full life of the home, including the CO2 emissions created during the build of a house and its day-to-day energy needs. This figure is then offset by the property’s ability to produce the energy it needs itself – through wind turbines, solar panels and other renewable sources of energy – all important elements that have been purpose-built into the home in the design.

If a property is able to become fully sustainable, and even have excess renewable energy supplies that can benefit others, then it’s become a fully zero carbon home. Part of the key to going zero carbon in the home is an awareness of how to make the property itself more energy efficient and finding ways to reduce our everyday energy needs.

How Is The UK Going Zero Carbon?

Making our homes zero carbon has hit the headlines recently, with plans unveiled by the government in December 2006 that would help to make all new homes in the UK zero carbon by an ambitious 2016. It has set out plans to encourage property developers and builders to include carbon efficient measures into building design, including sources of renewable energy generation, energy efficient walls and roofs, as well as devising new ways to encourage minimal energy consumption.

Gordon Brown also announced in his pre-budget report last December that eventually it would be compulsory for new buildings to be zero carbon, and that the UK was leading the way towards becoming a nation of green homeowners. Crucially, Brown also announced that environmentally-friendly homes would be exempt from stamp duty, making them cheaper for people to buy.

What About Existing Homes?

For existing homes, the new Energy Performance Certificates or EPCs, which rate a property between A-G on its energy efficiency, look likely to have a high impact in putting green issues high on homebuyer’s and seller’s wish lists – when they are eventually introduced.

As part of the controversial new Home Information Packs in England and Wales, it was announced that EPCs would be delayed until August 2007, when only property sales of four or more bedrooms would need to be graded on their energy efficiency. These will then be rolled out to smaller property types when more energy assessors, the trained inspectors who grade homes on energy efficiency, are available.

Welcoming Changes

The measures being taken to help make the UK’s homes zero carbon have been welcomed by environmental groups. According to Friends of the Earth campaigner Liz Murray: 'The key to low- and zero-carbon housing is maximising energy efficiency of these homes in the first instance and embedding within the design a means by which energy can be generated using micropower technologies as part of the structure. 'The sooner all developers do this the better.'

The Reality of Zero Carbon

But how easy is it to build a zero carbon home? It’s certainly not a cheaper way for developers to create homes, but it is possible by using innovative design and materials, and will be more and more common once measures are put in place that make green building compulsory. Currently however only a very small number of the 150,000 homes built each year are sufficiently green enough to be classified with zero carbon status.

But zero carbon homes do exist, most famously the BedZED housing estate in Sutton. There, a BedZED home needs only 10% of the energy needed to heat a standard home to the same temperature, and has a range of renewable energy sources that make it completely zero carbon.

Warning from the International Energy Agency

2008-12-11T23:27:00.002+07:00

Energy consumption is tied closely in to climate change issues, with the burning of fossil fuels impacting on global CO2 levels in particular. This makes the prospect of an ever increasing demand for more and more energy a bleak picture for the environment in the future indeed.

So when the International Energy Agency warned that an anticipated 50% increase in energy needs by 2030 would be served largely by coal reserves, there was an outcry from scientists and climate change advisers.

Who Are The International Energy Agency?

The International Energy Agency, or IEA, is a worldwide advisory body providing information to governments across world about all things energy related. This includes long-term analysis of the world's energy requirements, and projections on how this need will be served - in other words, the level of non-renewable and renewable energy sources needed for the world's commerce, industry and individuals.

Anticipated Growth In Energy Needs

According to the IEA's chief executive, Nobuo Tanaka, energy needs - if left unchecked by governments across the world - would rise by 50% by 2030 alone, and this need could only be realistically provided by coal reserves. This could have devastating effects on global CO2 levels and undo the global efforts to help fight climate change. If levels of energy creation from coal raised by this amount, the amount of CO2 emitted into the atmosphere as a result of this would rise by a staggering 57% - from 27 giga tonnes to 42 giga tonnes a year.

The Rise Of Industrialising Nations

Much of the increase in anticipated energy growth can be attributed to the industrialisation and economic development of several large countries - most notably India and China, whose joint populations total two billion. Levels of energy would need to complement a changing fortune for these two nations.

According to Mr Tanaka: " The emergence of new major players in global energy markets means that all countries must take vigorous, immediate and collective action to curb runaway energy demand… rapid economic development will undoubtedly continue to drive up energy demand in China and India… this is a legitimate aspiration that needs to be accommodated and supported by the rest of the world."

The Alternative Policy Scenario

The outlook for energy was somewhat less negative after the IEA took into consideration the various different long-term policies and commitments different nations had taken in order to curb their carbon footprint and reduce overall energy needs - including binding protocols such as the Kyoto treaty. Projections using these figures then suggest that CO2 emissions from energy would rise by 25% by 2030. This is still a worrying increase but halves the worst case scenario picture, which was based on nothing being done to check energy consumption.

A Global Solution To The IEA's Warning

There is, according to the IEA, the possibility to stabilise energy consumption at 2005 levels by 2030 - but that solution needs to be implemented globally and quickly. This includes an increased reliance of nuclear energy and more investment into CO2 storage technology.

It's a stark warning from the IEA, and is yet another reason why governments need to act on climate change now. Here in the UK, the climate change bill was announced in parliament, a binding commitment to reduce overall CO2 emissions, to the backdrop of this news. Elsewhere, other parts of the world are also beginning to act accordingly.

Winter Energy Savers

2008-12-11T22:36:00.004+07:00

When the nights draw in and the chill of winter hits our homes it’s the time to wrap up warm and enjoy the indoors. Unfortunately, it’s also the season that we tend to rack up high energy bills – especially after all the major energy companies raised their prices throughout 2006.

However there are ways to minimize the blow to your wallet this winter and still keep your home snug. If you’re smarter with the energy you use and prepare your property in advance of cold weather, you can keep winter energy costs as low as possible.

Insulate your Home

A lot of the energy we use to heat our homes is wasted due to properties being ill-prepared and under-insulated. Up to a third of heat produced in the home is lost through the walls, but some forward planning before the cold snap starts will help to retain as much heat in your home as possible.

Consider installing cavity wall insulation. This helps to keep heat inside the home and evenly distributes it around each room. Cavity wall insulation works by being injected into the cavity between the inner and outer layers of brickwork in your external wall and acting as a barrier to heat loss. Insulating your walls will cost around £260 for an average sized home, but with an annual energy bill reduction of £130-160, the investment will pay for itself after two years.

Invest in Draught Excluders

There are also some energy saving tricks you can put into action straightaway. Firstly, install draught excluders underneath all your doors. This is a quick and simple way to retain energy in each room by stopping cold draughts from circulating. Draught excluders can be inexpensively purchased from hardware and DIY shops, or you can make your own ‘door snake’ with leftover carpet cuttings and materials.

Similarly, you should also draught proof all windows in the home, particularly single glazed panes. Applying a sealant or self-adhesive strip will achieve this at a reasonable cost. Alternatively, investing in double glazing throughout your home will also reduce escaping heat significantly. If you’re unable to double glaze your entire property, think about double glazing for the rooms you tend to use and heat the most.

Keep Your Boiler in Good Shape

Your boiler going on the blink in the middle of winter can be both a cold and expensive inconvenience. Give your boiler an MOT before the winter months, and consider the benefits of taking out heating cover for your boiler. This will protect you from an unexpected repair bill if the worst does happen.

The average boiler lasts between 10-15 years, so next time you’re replacing yours, invest in a high efficiency condensing boiler that can cut your energy bills by £190-240 a year and significantly cut CO2 emissions. Or an extra money saver for your existing boiler is to fit an insulating jacket.

Take a Closer Look at your Energy Bills

Make sure you’re with the best value energy supplier before winter draws in and your bills start increasing. You should check if your current provider has any offers that you’re not currently taking advantage of. It’s also worth carrying out a check of tariffs offered by other energy suppliers. Try using an impartial comparison and switching website to see if you could save money by switching to another energy supplier.

Water Saving Tips

2008-12-11T22:10:00.006+07:00

Despite being an island surrounded by water it doesn’t take long for some areas in the UK to run dry come summer. During 2006, several water companies issued hosepipe and sprinkler bans, and almost declared further restrictions on the remaining supply.

Being efficient all year round with water will help ensure our reservoirs remain at a healthy level. It also pays to reduce the amount you use, as more and more of us are switching or move to water metered supplies. Here are some water saving tips to help you on your way to reducing, preserving and using water wisely.

Fix Leaky Taps

Not only are they irritating to hear day in, day out, they also waste an excessive amount of water. A tap losing one drop a second wastes 15 litres of water a day. Usually tightening the tap will solve the problem, otherwise enlist the help of someone who knows what they’re doing.

Take a Shower instead of a Bath

A long soak in the bath is a great relaxant, but did you know that having just one can use up to 100 litres of water? An average shower cuts your water consumption by a third and leaves you just as clean, so have a bath as a treat instead of part of your daily routine. However, beware – some modern power showers used are also water guzzlers, so turn down from the maximum setting to use in moderation.

Save Water in the Kitchen

There are lots of things you can do in the kitchen to help save water. Instead of running the tap till it gets cold to drink, keep a handy jug of chilled water to drink. When boiling the kettle to cook or make a cup of tea, only boil as much as you need. And rather than wash potatoes and other vegetables under the tap, wash all of them in a single bowl of water. Even making small changes like these will help reduce daily water consumption.

Water Efficient Appliances

You can make high water consumption products more efficient in the way they run by taking advantage of some of the free or cheap products that the main water companies offer. For example, a hippo or save-a-flush is an unnoticeable addition to your toilet but can save up to 2,000 gallons of water a year.

In the long term, you may wish to consider a dual flush toilet that flushes with less water. And when you next come to replace washing machines or dishwashers, try and purchase an energy efficient model as these are also designed to use less water.

Install a Water Butt

Gathering rain water outside using a water butt is an efficient and cheap way to water flowers and plants. It can keep your garden in top condition without using a sprinkler or hosepipe. Water butts, which are lightweight and barrel sized, are usually available at a discounted price from your council.

Turn Off the Tap

It’s an old cliché, but turning the tap off when brushing your teeth saves more water than you may realise - over six litres every minute. If the entire adult population of England and Wales remembered to do this, we could save 180 mega litres a day, enough to supply nearly 500,000 homes. Also try and make a conscious attempt to turn off the tap when shaving and washing your face in the basin.

Only Wash a Full Load

Whether it’s a load of washing in the washing machine or dishes in the dishwasher, only switch on if you’ve got a full load to wash. That way, you’ll be making optimum use of the water that’s used in a cycle, and avoid using these appliances needlessly. It’s also possible on most modern machines to select a half load option which will reduce the amount of water used accordingly.

Sprinklers and Hosepipes

Hosepipes use around 1,000 litres of water an hour; sprinklers even more. Leave them in the shed in favour of more water efficient alternatives. Use leftover water and rainwater from your water butt for the garden. Washing the car the old fashioned way – with bucket and sponge – is equally as effective but miles more efficient.

Pipe Lagging

Ensure your water pipes and external taps are lagged in time for the cold winter months. If pipes are more heat efficient, it will help avoid them freezing, leaking or even bursting, which wastes high quantities of water. Insulating pipes will also save you on your winter heating bills.

Flush with Care

Currently the average person in the UK flushes the toilet 35 times a week, but not always for the right reasons. Try and avoid flushing away tissues, cotton balls, make-up facial wipes. Put them in the bin to avoid a needless flush.

Passive Solar Energy use

2008-12-11T01:40:00.002+07:00

By Emil Bedi, CANCEE and Hakan Falk, "Energy Saving Now".

Comments by Energy Saving Now.
The following sample house, in article about Passive Solar design, do not comply with our understanding of sustainability or efficiency. It represents popular opinions within the Architectural community and from this point of view it is very interesting. It also promotes an understanding of thermal mass and wider temperature bandwidth, that are essential issues for energy saving and as such very positive. About the sample (not the principles), we have the following to clarify,

The displayed building is very nice to look at and we find it attractive from a design perspective.

Many of the principles mentioned are important and complaint with what we are promoting on Energy Saving Now.

The sample building with large glass areas and the functionality is only valid for very limited geographical areas.

The savings are expected to be 15% and we assume that this is in comparison to normal buildings in USA and the area where it is built. If it is compared to a building according to the Swedish Building Codes, the energy consumption will be 2 to 3 times higher than the Swedish house. If it is located in a cold or warm climate, the surface temperature on the glassed areas will be very uncomfortable.

A 15% energy saving can be achieved in many easier ways and even in existing buildings. If you use paint for the building, that are Aluminium based instead of normally Titan, the saving will be around 15% and work in all geographical areas. It would also provide better comfort.

With the extended allowed temperature variation and operation policies, nearly all buildings will give 15% or better performance.

Sustainable buildings, based on long experience, was standard until a couple of hundred years ago. They used the location, thermal mass and/or insulation. A very common feature was the small window openings and covering of the windows to regulate the indoor temperatures depending on time of day and seasonal changes.

The values of the sample are the emphasises on thermal mass and natural regulation of the environment. This is opposing the current energy wasting design principles in the building and HVAC industry and as such very refreshing. The sample can be discussed and there are much more efficient ways to design for energy efficiency. We suggest that you carefully assimilate the information on "Energy Saving Now", before you go ahead and build. But if you absolutely want to build a glass house, read this article carefully.

Article about passive solar design.
Passive solar design, or climate responsive buildings use existing technologies and materials to heat, cool and light buildings. They integrate traditional building elements like insulation, south-facing glass, and massive floors with the climate to achieve sustainable results. These living spaces can be built for no extra cost while increasing affordability through lower energy payments. In many countries they also keep investment in the local building industry rather than transferring them to short term energy imports. Passive solar buildings are better for the environment while contributing to an energy independent, sustainable energy future.
Passive solar system uses the building structure as a collector, storage and transfer mechanical equipment. This definition fits most of the more simple systems where heat is stored in the basic structure: walls, ceiling or floor. There are also systems that have heat storage as a permanent element within the building structure, such as bins of rocks, or water-filled drums or bottles. These are also classified as passive solar energy systems. Passive solar homes are ideal places in which to live. They provide beautiful connections to the outdoors, give plenty of natural light, and save energy throughout the year.

HISTORY
Building design has historically borrowed its inspiration from the local environment and available building materials. More recently, humankind has designed itself out of nature, taking a path of dominance and control which led to one style of building for nearly any situation. In 100 A.D., Pliny the Younger, a historical writer, built a summer home in Northern Italy featuring thin sheets of mica windows on one room. The room got hotter than the others and saved on short supplies of wood. The famous Roman bath houses in the first to fourth centuries A.D. had large south facing windows to let in the sun’s warmth. By the sixth century, sunrooms on houses and public buildings were so common that the Justinian Code initiated “sun rights” to ensure individual access to the sun. Conservatories were very popular in the 1800’s creating spaces for guests to walk through warm greenhouses with lush foliage.

Passive solar buildings in the United States were in such demand by 1947, as a result of scarce energy during the prolonged World War 2, that Libbey-Owens-Ford Glass Company published a book entitled Your Solar House, which profiled forty-nine of the nations greatest solar architects.

In the mid-1950’s, architect Frank Bridgers designed the world’s first commercial office building using solar water heating and passive design. This solar system has been continuously operating since that time and the Bridgers-Paxton Building is now in the National Historic Register as the world’s first solar heated office building.
Low oil prices following World War 2 helped keep attention away from solar designs and efficiency. Beginning in the mid-1990’s, market pressures are driving a movement to redesign our building systems to more in line with nature.

Passive Solar Space Heating

There are few basic architectural modes for the utilisation of passive solar utilisation in architecture. But these modes, as presented below, can be developed into many different scheme, and enrich the design.

The essential elements of a passive solar home are: good siting of the house, many south-facing windows (in Northern Hemisphere) to admit solar energy in winter (and, conversely, few east or west facing windows, to limit the collection of unwanted summer sunshine), sufficient interior mass (thermal mass) to smooth out undesirable temperature swings and to store heat for night time and a well-insulated building envelope.

Siting, insulation, windows orientation and mass must be used together. For least variation of indoor temperature the insulation should be placed on the outside of the mass. However where rapid indoor heating is required some insulation or low heat capacity material should be placed at the inside surface. There will be an optimum design for each micro-climate and indications are that a careful balance between mass and insulation in a structure will result not only in energy savings but in initial material cost saving as well.

Site
Landscaping and Trees
According to the U.S. Department of Energy report, “Landscaping for Energy Efficiency” (DOE/GO-10095-046), careful landscaping can save up to 25% of a household’s energy consumption for heating and cooling. Trees are very effective means of shading in the summer months as well as providing breaks for the cool winter winds. In addition to contributing shade, landscape features combined with a lawn or other ground cover can reduce air temperatures as much as 5 degrees Celsius in the surrounding area when water evaporates from vegetation and cools the surrounding air. Trees are wonderful for natural shading and cooling, but they must be located appropriately so as to provide shade in summer and not block the winter sun. Even deciduous trees that lose their leaves during cold weather block some winter sunlight - a few bare trees can block over 50 percent of the available solar energy.

Windows

All effective passive systems depend on windows. Glass or other translucent materials allow short-wave, solar radiation to enter a building and prohibit the long-wave, heat radiation, from escaping. Windows control the energy flow in two principle ways: they admit solar energy in winter, so warming the house above the otherwise cool to cold internal conditions; and by excluding sun from the windows (by orientation and shading) there exist the opportunity to use ventilation to cool the otherwise warm hot house in summer. If use is to be made of the sun’s heat, then it has to reach buildings when it is useful. Generally, the sun should be able to reach the collection area between 9 a.m. and 3 p.m. in winter with as little obstruction and interference as possible.Trees on the site or the neighbours’ site might shade the vital areas of the building. This need to be checked and the building located to minimise any such interference. It is possible to plan a house to have its main outlook in any direction and still be an efficient low energy building. The building envelope, i.e. the walls, floor and roof are the important elements in design, rather than the location of internal spaces. If a window needs to face west it requires correct shading and its size restricted.

Glass permits sun radiation of wavelengths 0.4 to 2.5 microns to pass through it. As this radiant energy collides with opaque objects on the other side of the glass, it’s wavelength increases to 11 microns. Glass acts as an opaque barrier to light of this wavelength thereby trapping the sun’s energy. The amount of light penetrating a glass is dependent on the angle of incidence. The optimum angle of incidence is 90o. When sunlight strikes the glass at 30o or less, the most radiation is reflected.

Understanding the Solar Spectrum and Heat Transfer
To make good choices on glazing, it is needed to understand a bit about light and heat. The sunlight that strikes the Earth is comprised of a variety of wavelengths and different glazing will selectively transmit, absorb, and reflect the various components of the solar spectrum. Likewise, reducing glare (via reflection or tinting) is helpful in the workplace by allowing the transmission of visible, or natural, light it is possible to save energy for artificial light. But perhaps the greatest effect on human comfort levels is determined by infrared heat transfer. By specifying the right type of glass, it is possible to trap the infrared heat for warmth, or reflect the infrared heat to prevent warming.

There are three ways that heat moves through a glazing material. The first is conduction. Conductive heat is transferred through the glazing by direct contact. Heat can be felt by touching the glazing material. The second form of heat transfer is radiation; electromagnetic waves carry heat through a glazing. This produces the feeling of heat radiating from the surface of the glazing. The third method of heat transfer is convection. Convection transfers heat by motion, in this case, air flow. The natural flow of warm air toward colder air allows heat to be lost or gained.
The R-value of a glazing - its insulating capabilities or resistance to the flow of heat - is determined by the degree of conduction, radiation, and convection through the glazing material. However, air infiltration will also determine the overall R-value of a glazing system. The amount of heat that travels around a glazing is as important as the heat transfer through a glazing. Air can leak in or out of a building around the glazing via the framing. The quality, workmanship, and the installation of the entire glazing system, including the framing, affects air infiltration.
Advances in glass technology have perhaps been the single largest contributor to building efficiency since the 1970s and they play an important roll in solar design. Some window advances include:

Double and triple pane windows with much higher insulating values.

Low emissivity or Low-E glass employing a coating which lets heat in but not out.

Argon (and other) gas filled windows that increase insulating values above windows with just air.

Phase-change technologies that can switch from opaque to translucent when a voltage is applied to them.

Basic Glass Types
Glazing materials include glass, acrylics, fibreglass, and other materials. Although different glazing materials have very specific applications, the use of glass has proven the most diverse. The various types of glass allow the passive solar designer to fine-tune a structure to meet client needs. The single pane is the simplest of glass types, and the building block for higher performance glass. Single panes have a high solar transmission, but have poor insulation - the R-value is about 1,0. Single pane glass can be effective when used as storm windows, in warm climate construction (unless air conditioning is being used), for certain solar collectors, and in seasonal greenhouses. Structures using single pane glass will typically experience large temperature swings, drafts, increased condensation, and provide a minimal buffer from the outdoors.

Perhaps the most common glass product used today is the double pane unit. Double pane glass is just that: two panes manufactured into one unit. Isolated glass (thermopane) incorporate a spacer bar (filled with a moisture absorbing material called a desiccant) between the panes and are typically sealed with silicone. The spacer creates a dead air space between the panes. This air space increases the resistance to heat transfer; the R-value for double pane is about 1,8-2,1. Huge air spaces will not drastically increase R-value. In fact, a large air space can actually encourage convective heat transfer within the unit and produce a heat loss. A rule of thumb for air space is between 1 and 2 centimetres. It is also possible to go as large as 10-12 centimetres without creating convective flow, but at that point you are dealing with a very large and awkward unit. The demand for greater energy efficiency in building and retrofitting homes has made insulated glass units the standard. With good solar transmission and fair insulation, such unit is a large improvement over the single pane. Windows, doors, skylights, sunrooms, and many other areas utilize double pane glass.

HIGH PERFORMANCE GLASS
High performance or enhanced glass offers even better R-value and solar energy control. By further improving the insulating capability of glass, it is possible dramatically increase also design options. What were once insulated walls may become sunrooms. Solid roofs and ceilings become windows to the sky. Dark rooms can “wake up” to natural light, solar heat gain, and wonderful views. For a relatively small increase in cost it is possible to improve efficiency, provide better moisture and UV protection, and gain design flexibility. A variety of high performance glass is now available.

What are the advantages of this glass? Low emissivity (Low-E) glass is succeeding double pane glass in energy efficient buildings. Emissivity is the measure of infrared (heat) transfer through a material. The higher the emissivity, the more heat is radiated through the material. Conversely, the lower the emissivity, the more heat is reflected by the material. Low-E coatings will reflect, or re-radiate, the infrared heat back into a room, making the space warmer. This translates into R-values from 2.6 to 3.2. In warmer climates it is possible to reverse the unit and re-radiate infrared heat back to the outside, keeping the space cooler. Low-E glass improves the R-value, UV protection, and moisture control.Gas-filled windows increase R-value. Properly done, gas-filling will increase the overall R-value of a glass unit by about 1,0. The air within an insulated glass unit is displaced with an inert, harmless gas with better insulation properties. Typical gases used are Krypton and Argon.

Window curtains
In addition to decorative functions, curtains can be used to reduce the heat losses that occur during the cold months as well as the heat gains during the warmer months. The plywood box over the curtain top prevents warm ceiling air from moving between the glass and curtain. The curtain should drop at least 30 cm below the window for it to be effective. The optimum condition would be for it to drop to the floor.

Thermal mass
Solar radiation hitting walls, windows, roofs and other surfaces is adsorbed by the building and is stored in thermal mass. This stored heat is then radiated to the interior of the building. Thermal mass in a solar heating system performs the same function as batteries in a solar electric system (see chapter on photovoltaics). Both store solar energy, when available, for later use.

Thermal mass can be incorporated into a passive solar room in many ways, from tile-covered floors to water-filled drums. Thermal mass materials, which include slab floors, masonry walls, and other heavy building materials, absorb and store heat. They are a key element in passive solar homes. Homes with substantial south-facing glass areas and no thermal storage mass do not perform well.

It is important to know that dark surfaces reflect less, therefore, absorb more heat. In case of a dark tiled floor, the floor will be able to absorb heat all day and radiate heat into the room at night. The rate of heat flow is based on the temperature difference between heat source and the object to which the heat flows. As described above heat flows in three ways - conduction (heat transfer through solid materials), convection (heat transfer through the movement of liquids or gasses), and radiation. All surfaces of a building lose heat via these three modes. Good solar design works to minimize heat loss and maximize efficient heat distribution. The need for thermal mass (heat-storage materials) inside a building is very climate-dependent. Heavy buildings of high thermal mass are consistently more comfortable during hot weather in hot-arid and cool-temperate climates, while in hot-humid climates there is little benefit. In cool-temperature climates the thermal mass acts as a cold-weather heat store thus improving overall comfort and reducing the need for auxiliary heating, except on overcast or very cold days. In intermittently heated buildings, however, it tends to increase the heat needed to maintain the chosen conditions.

Providing adequate thermal mass is usually the greatest challenge to the passive solar designer. The amount of mass needed is determined by the area of south-facing glazing and the location of the mass. In order to ensure an effective design it is important to follow these guidelines:

Locate the thermal mass in direct sunlight. Thermal mass installed where the sun can reach it directly is more effective than indirect mass placed where the sun’s rays do not penetrate. Houses that rely on indirect storage need three to four times more thermal mass than those using direct storage.

Distribute the thermal mass. Passive solar homes work better if the thermal mass is relatively thin and spread over a wide area. The surface area of the thermal mass should be at least 3 times, and preferably 6 times, greater than the area of the south windows. Slab floors that are 8 to 10 centimetres thick are more cost effective and work better than floors 16 to 20 inches thick.

Do not cover the thermal mass. Carpeting virtually eliminates savings from the passive solar elements. Masonry walls can have drywall finishes, but should not be covered by large wall hangings or lightweight panelling. The drywall should be attached directly to the mass wall, not to covers fastened to the wall that create an undesirable insulating airspace between the drywall and the mass.

Select an appropriate mass colour. For best performance, finish mass floors with a dark colour. A medium colour can store 70 percent as much solar heat as a dark colour, and may be appropriate in some designs. A matte finish for the floor reduces reflected sunlight, thus increasing the amount of heat captured by the mass and having the additional advantage of reducing glare. The colour of interior mass walls does not significantly affect passive solar performance.

Insulate the thermal mass surfaces. There are several techniques for insulating slab floors and masonry exterior walls. These measures should introduced to achieve the energy savings. Unfortunately, problems in some case can arise like with termite infestations in foam insulation for perimeter slabs. This can complicate the issue of whether and how to insulate slab-on-grade floors.

Make thermal mass multipurpose. For maximum cost effectiveness, thermal mass elements should serve other purposes as well. Masonry thermal storage walls are one example of a passive solar design that is often cost prohibitive because the mass wall is only needed as thermal mass. On the other hand, tile-covered slab floors store heat, serve as structural elements, and provide a finished floor surface. Masonry interior walls provide structural support, divide rooms, and store heat.

When developing a thermal storage system or simply comparing materials it is useful to look at the storage capacity of the proposed building materials which is referred to as the volumetric heat capacity (J/m3. Deg. Celsius) or more commonly the specific heat and the rate at which the material can take up and store heat. Some examples of common storage materials are given in the following table:

Material	Density (kg/m3)	Volumetric heat capacity (J/m3. Deg. C)
Water	1000	4186
Concrete	2100	1764
Brick	1700	1360
Stone: marble	2500	2250
	Materials not suitable for thermal storage
Plasterboard	950	798
Timber	610	866
Glass fibre matt	25	25

Early solar designers used water (stored in large containers) as the heat storage medium. Although water is cheap, the containers and the space they take are not. Some solar designers turned to rock storage bins as reservoirs for thermal mass. It took three times as much rock to store the same amount of heat as an equivalent volume of water and the moist warm environment of the bins became breeding grounds for odor producing fungi and bacteria. The high cost and the foul odors started to give solar design a bad name. Both water and rock heat storage require complicated control systems, pumps, and blowers. Heat storage is not common in today‘s solar energy utilisation. Main reason for this is that all of these systems rely on electricity, require maintenance, and are subject to periodic breakdown.

Thermal insulation

Materials generally available for building purposes can be classified into two generic groups - bulk materials and reflective foil laminates (RFL). The first of these relies on the resistance of air trapped in pockets between the fibres of the blanket type materials (mineral fibre materials) or the cells formed in the foamed structure of board or slab type materials (usually made from plastics such as polystyrene and polyurethane foams). The second reflects radiant energy away from the object or surface being protected. Thermal insulation in the outer fabric of a building is a vital component of an energy-efficient design strategy. The key to successful energy-efficient design is the control of heat flow through the external fabric. All the solar energy gained could be easily lost from an inadequately insulated building before it is able to be of benefit. It will have been noted that some materials have a very much higher thermal resistance per unit thickness than others irrespective of their density. The fact that air is a good insulator especially if it is bounded by a bright foil surface to limit radiation transfer can be very useful as well.

Cooling
In many parts of the world a passive solar building needs cooling as much as heating. One of the best, time proven methods of cooling is thermal coupling with the earth’s constant temperature. Dropping the ground floor at least one meter into the earth provides a more even exterior temperature which aids cooling as well as heating. Adequate structural engineering, drainage, and damp proofing are essential in below ground areas. Thermal isolation is the best and most economical way to temper the building’s environment. Using the earth’s thermal mass keeps the house at a reasonable temperature, and so does good insulation. Shades located outside and inside the windows, ventilation and reflective films on the windows are also very important in order to control temperature inside the building.

External Shades and Shutters
Exterior window shading treatments are effective cooling measures because they block both direct and indirect sunlight outside of the home. Solar shade screens are an excellent exterior shading product with a thick weave that blocks up to 70 percent of all incoming sunlight. The screens absorb sunlight so they should be used on the exterior of the windows. From outside, they look slightly darker than regular screening, but from the inside many people do not detect a difference. Most products also serve as insect screening. They should be removed in winter to allow full sunlight through the windows. A more expensive alternative to the fibreglass product is a thin, metal screen that blocks sunlight, but still allows a view from inside to outside. Hinged decorative exterior shutters which close over the windows are also excellent shading options. However, they obscure the view, block daylight completely, may be expensive and may be difficult for many households to operate on a daily basis.

Interior Shades and Shutters
Shutters and shades located inside the house include curtains, roll-down shades, and Venetian blinds. Interior shutters and shades are generally the least effective shading measures because they try to block sunlight that has already entered the room. However, if passive solar windows do not have exterior shading, interior measures are needed. The most effective interior treatments are solid shades with a reflective surface facing outside. In fact, simple white roller blinds keep the house cooler than more expensive louvered blinds, which do not provide a solid surface and allow trapped heat to migrate between the blinds into the house.

Reflective Films and Tints
Reflective film, which adheres to glass and is found often in commercial buildings, can block up to 85% of incoming sunlight. The film blocks sunlight all year, so it is inappropriate on south windows in passive solar homes. However, it may be practical for unshaded east and west windows. These films are not recommended for windows that experience partial shading because they absorb sunlight and heat the glass unevenly. The uneven heating of windows may break the glass or ruin the seal between double-glazed units.

Ventilation
Ventilation is the changing of air in buildings to control oxygen, heat and contaminants. Ventilation may occur in few forms. Building orientation, form, plan and user actions also alter air flow paths. Natural ventilation consumes no energy and has few if any running costs, but depends on weather conditions and can be difficult to control. Mechanical and air-conditioned ventilation are energy-driven alternatives to natural ventilation, normally dictated by building type, site and function. They can be particularly efficient as supplements to natural ventilation. Mechanical ventilation uses fans and ducts to supply and extract air in localised areas such as a kitchen. Air conditioning both treats and supplies air. It is particularly useful to cool air below ambient temperatures.

SOLAR ARCHITECTURE & ACTIVE SYSTEMS
It is important to design the house with the aim to incorporate active solar systems (see below) like collectors or photovoltaic modules as well. The building should orient these appliances due south. Tilt of the solar collectors should be in Europe and North America more than 50° (from horizontal) to maximize winter heat collection. Solar collectors should be thermally locked with the roof. Non-tracking photovoltaics receive the most yearly insolation (exposure to the sun’s rays) when tilted at an angle, from horizontal, equal to the building’s latitude. Design of the building’s roof should be done to such angles and southern orientation as integral aspects of the building. Hot water collectors and photovoltaic panels should be located as close as possible to their main areas of use. It is important to concentrate these areas of use. For example, putting the bathrooms and kitchen close together economizes on their installation and minimizes energy loss. All appliances should be selected with efficiency as the prime criterion.

SUMMARY

Passive use of sunlight contributes around 15% of space heating needs in typical building. It is important source of energy savings which can be utilised everywhere and almost at no extra cost. There are some principles which can help a designer to harness solar energy through thermally efficient buildings.

SITE
It is important to become familiar with the energy flows of house surroundings. The nature and relationship of the lay of the land, water courses, vegetation, soil types, wind directions, and exposure to the sun should be investigated. A site suitable for solar design should balance and complement these elements. It must have unobstructed exposure to the sun from 9 am to 3 pm during the heating season.

HEATING
In Northern hemisphere orientation due south of the main solar insolating spaces, i.e. greenhouse, and/or main daytime activity areas is important. Glass should be open to the sun patterns during the winter. By facing of the windows to the south, and virtually none to the north maximaze solar gain. Multiple pane glass in all windows is recommended.

THERMAL MASS
Thermal mass including masonry floors, walls and water storage is important to absorb ambient heat during the day and release it at night. Insulation of the building further minimize heat loss through windows, walls and roof.

NATURAL HEAT FLOW
It is useful to design the house with the natural heat flow in mind. Hot air rises, so placing some activity areas on a second floor to draw heat up from a lower collector area and across other areas can save a lot of energy. Buffer areas of the building (unheated rooms, or partially heated spaces such as utility rooms, vestibules and storage areas) should be oriented due to the north to lessen the impact of the winter’s cold. Using a vestibule on doors to the exterior can lead to energy savings. Vestibules cut heat loss and provide a buffer zone between the exterior and the interior.

Energy in the Sun

2008-12-11T00:32:00.001+07:00

By Emil Bedi, CANCEE and Hakan Falk, "Energy Saving Now".

SOLAR RADIATION

Solar radiation is electromagnetic radiation in the 0.28...3.0 µm wavelength range. The solar spectrum includes a small share of ultraviolet radiation (0.28...0.38 µm) which is invisible to our eyes and comprises about 2% of the solar spectrum, the visible light which range from 0.38 to 0.78 µm and accounts for around 49% of the spectrum and finally of infrared radiation with long wavelength (0.78...3.0 µm), which makes up most of the remaining 49% of the solar spectrum.

HOW MUCH SOLAR ENERGY STRIKES THE EARTH?
The sun generates an enormous amount of energy - approximately 1.1 x 10 E20 kilowatt-hours every second. (A kilowatt-hour is the amount of energy needed to power a 100 watt light bulb for ten hours.) The earth’s outer atmosphere intercepts about one two-billionth of the energy generated by the sun, or about 1500 quadrillion (1.5 x 10 E18 ) kilowatt-hours per year. Because of reflection, scattering, and absorption by gases and aerosols in the atmosphere, however, only 47% of this, or approximately 700 quadrillion (7 x 10 E17 ) kilowatt-hours, reaches the surface of the earth.

In the earth’s atmosphere, solar radiation is received directly (direct radiation) and by diffusion in air, dust, water, etc., contained in the atmosphere (diffuse radiation). The sum of the two is referred to as global radiation.

The amount of incident energy per unit area and day depends on a number of factors, e.g.:
latitude
local climate
season of the year
inclination of the collecting surface in the direction of the sun.

TIME AND SITE
The solar energy varies because of the relative motion of the sun. This variations depend on the time of day and the season. In general, more solar radiation is present during midday than during either the early morning or late afternoon. At midday, the sun is positioned high in the sky and the path of the sun’s rays through the earth’s atmosphere is shortened. Consequently, less solar radiation is scattered or absorbed, and more solar radiation reaches the earth’s surface.The amounts of solar energy arriving at the earth’s surface vary over the year, from an average of less than 0,8 kWh/m2 per day during winter in the North of Europe to more than 4 kWh/m2 per day during summer in this region. The difference is decreasing for the regions closer to the equator.
The availability of solar energy varies with geographical location of site and is the highest in regions closest to the equator. Thus the average annual global radiation impinging on a horizontal surface which amounts to approx. 1000 kWh/m2 in Central Europe, Central Asia, and Canada reach approx. 1700 kWh/m2 in the Mediterranian and to approx. 2200 kWh/m2 in most equatorial regions in African, Oriental, and Australian desert areas. In general, seasonal and geographical differences in irradiation are considerable (see the table bellow) and must be taken into account for all solar energy applications.

Variations of solar irradiation (tilt angle South 30Deg.) in Europe and Caribbean region in kWh/m2.day.

	Southern Europe	Central Europe	North Europe	Caribbean
January	2,6	1,7	0,8	5,1
February	3,9	3,2	1,5	5,6
March	4,6	3,6	2,6	6,0
April	5,9	4,7	3,4	6,2
May	6,3	5,3	4,2	6,1
June	6,9	5,9	5,0	5,9
July	7,5	6,0	4,4	6,0
August	6,6	5,3	4,0	6,1
September	5,5	4,4	3,3	5,7
October	4,5	3,3	2,1	5,3
November	3,0	2,1	1,2	5,1
December	2,7	1,7	0,8	4,8
YEAR	5,0	3,9	2,8	5,7

CLOUDS
The amount of solar radiation reaching the earth’s surface varies greatly because of changing atmospheric conditions and the changing position of the sun, both during the day and throughout the year. Clouds are the predominant atmospheric condition that determines the amount of solar radiation that reaches the earth. Consequently, regions of the nation with cloudy climates receive less solar radiation than the cloud-free desert climates. For any given location, the solar radiation reaching the earth’s surface decreases with increasing cloud cover. Local geographical features, such as mountains, oceans, and large lakes, influence the formation of clouds; therefore, the amount of solar radiation received for these areas may be different from that received by adjacent land areas. For example, mountains may receive less solar radiation than adjacent foothills and plains located a short distance away. Winds blowing against mountains force some of the air to rise, and clouds form from the moisture in the air as it cools. Coastlines may also receive a different amount of solar radiation than areas further inland.
The solar energy which is available during the day varies and depends strongly on the local sky conditions. At noon in clear sky conditions, the global solar irradiation can in e.g. Central Europe reach 1000 W/m2 on a horizontal surface (under very favourable conditions, even higher levels can occur) whilst in very cloudy weather, it may fall to less than 100 W/m2 even at midday.

POLLUTION
Both man-made and naturally occurring events can limit the amount of solar radiation at the earth’s surface. Urban air pollution, smoke from forest fires, and airborne ash resulting from volcanic activity reduce the solar resource by increasing the scattering and absorption of solar radiation. This has a larger impact on radiation coming in a direct line from the sun (direct radiation) than on the total (global) solar radiation. On a day with severely polluted air (smog alert), the direct solar radiation can be reduced by 40%, whereas the global solar radiation is reduced by 15% to 25%. A large volcanic eruption may decrease, over a large portion of the earth, the direct solar radiation by 20% and the global solar radiation by nearly 10% for 6 months to 2 years. As the volcanic ash falls out of the atmosphere, the effect is diminished, but complete removal of the ash may take several years.

POTENTIALS
Solar radiation provides us at zero cost with 10,000 times more energy than is actually used worldwide. All people of the world buy, trade, and sell a little less than 85 trillion (8.5 x 10E13 ) kilowatt-hours of energy per year. But that’s just the commercial market. Because we have no way to keep track of it, we are not sure how much non-commercial energy people consume: how much wood and manure people may gather and burn, for example; or how much water individuals, small groups, or businesses may use to provide mechanical or electrical energy. Some think that such non-commercial energy may constitute as much as a fifth of all energy consumed. But even if this were the case, the total energy consumed by the people of the world would still be only about one seven-thousandth of the solar energy striking the earth’s surface per year.

In some developed countries like in the United States people consume roughly 25 trillion (2.5 x 10E13 ) kilowatt-hours per year. This translates to more than 260 kilowatt-hours per person per day - this is the equivalent of running more than one hundred 100 watt bulbs all day, every day. U.S. citizen consumes 33 times as much energy as the average person from India, 13 times as much as the average Chinese, two and a half times as much as the average Japanese, and twice as much as the average Sweden.

Even in such heavy energy consuming countries like USA solar energy falling on the land mass can many times surplus the energy consumed there. If only 1% of land would be set aside and covered by solar systems (such as solar cells or solar thermal troughs) that were only 10% efficient, the sunshine falling on these systems could supply this nation with all the energy it needed. The same is true for all other developed countries. In a certain sense, it is impractical - besides being extremely expensive, it is not possible to cover such large areas with solar systems. The damage to ecosystems might be dramatic. But the principle remains. It is possible to cover the same total area in a dispersed manner - on buildings, on houses, along roadsides, on dedicated plots of land, etc. In another sense, it is practical. In many countries already more than 1% of land is dedicated to the mining, drilling, converting, generating, and transporting of energy. And the great majority of this energy is not renewable on a human scale and is far more harmful to the environment than solar systems would prove to be.

SOLAR ENERGY UTILISATION
In most places of the world much more solar energy hits a home’s roof and walls as is used by its occupants over a year’s time. Harnessing this sun’s light and heat is a clean, simple, and natural way to provide all forms of energy we need. It can be absorbed in solar collectors to provide hot water or space heating in households and commercial buildings. It can be concentrated by parabolic mirrors to provide heat at up to several thousands degrees Celsius. This heat can be used either for heating purposes or to generate electricity. There exist also another way to produce power from the sun - through photovoltaics. Photovoltaic cells are devices which convert solar radiation directly into electricity.

Solar radiation can be converted into useful energy using active systems and passive solar design. Active systems are generally those that are very visible like solar collectors or photovoltaic cells. Passive systems are defined as those where the heat moves by natural means due to house design which entails the arrangement of basic building materials to maximize the sun’s energy.

Solar energy can be converted to useful energy also indirectly, through other energy forms like biomass, wind or hydro power. Solar energy drives the earth´s weather. A large fraction of the incident radiation is absorbed by the oceans and the seas, which are warmed than evaporate and give the power to the rains which feed hydro power plants. Winds which are harnessed by wind turbines are getting its power due to uneven heating of the air. Another category of solar-derived renewable energy sources is biomass. Green plants absorb sunlight and convert it through photosynthesis into organic matter which can be used to produce heat and electricity as well. Thus wind, hydro power and biomass are all indirect forms of solar energy.