Plants have been using the energy from the sun for billions of years. Until recently, however, this energy has been available only indirectly to humans via the energy we harvest in the form of everything from fossil fuels to plants to wind power (all solar energy derivatives).
Today, as environmental awareness and rising oil prices put pressure on society, the potential of emerging solar energy technologies that directly harness the nearly limitless energy of the sun is increasingly desirable and economically feasible.
Harnessing Solar Energy
Harnessing solar energy involves both the direct use of the radiated heat as well as its conversion to electricity in the most efficient way possible. There are three categories that define every type of solar energy technology.
First, passive solar collection begins with the design of the building and includes optimal location, windows facing south, walls that absorb heat and light, and plenty of insulation. The heat and light that is collected is used in its original form of heat or light such as in a greenhouse. For example, the chapel on the Massachusetts Institute of Technology campus has no windows, but has been designed such that natural light reflects off the surrounding moat and into the room. Passive collection is much easier to include in new construction because retrofitting an existing building can be difficult and costly. Active solar collection implies converting solar energy to a more usable form of heat or electricity.
A second distinction is the type of energy an active solar system creates. Thermal applications include heat collection and heat-driven mechanisms, such as converting water to steam to power a steam engine that generates electricity. Electric processes use photovoltaic cells that create a moving electric charge that produces a direct electric current. PV panels have been used successfully on satellites and have a life expectancy of thirty years, making them an economically viable option for commercial use.
Finally, a third distinction in solar energy concerns the degree of concentration used in harnessing the suns energy. Concentrating systems engage mirrors and lenses to direct the sunlight to the area of collection. In some systems, parabolic trough-shaped structures of photovoltaic cells can even be powered to follow the motion of the sun allow for increased electricity generation. Non-concentrating systems are often simple flat panel collectors that are most commonly found as rooftop PV or as solar pool heaters.
The Solar Electricity Industry
In 2005, the amount of electricity generated by photovoltaic systems increased by 56% and resulted in 1,445 megawatts (MW) of PV being installed in the United States, Germany, Japan, among others. At the average of $8.00 per watt, this is a worldwide $12 billion investment in the solar energy markets in 2005 alone. Due to this market growth and increased capital for research and development, production costs for solar electricity are decreasing by five to seven percent per year.
Japan and Germany support the two largest solar markets due to targeted government subsidies designed to stimulate their growth. Japanese companies produced 47% of the PV cells manufactured globally in 2005, while Germany represented half of the installations. The US, once a leader in this technology represented less than 10% of both production and installations globally in 2005.
Worldwide, solar currently provides less than one percent of electricity demand but is projected to supply 26% of the worlds consumption by 2040. This industrial transition will occur as solar generated electricity becomes cost effective throughout the United States and much of the world.
Advantages of Solar Energy
Solar energy enjoys many environmental and economic advantages over other forms of energy currently used. These include:
Environmentally Friendly
Non-polluting: Solar electricity generation produces no emissions while the current alternative, fossil fuel combustion, releases more than a pound of carbon dioxide emissions for every kilowatt hour.
Non-consumptive: The suns radiation is a limitless resource that can be collected without the environmentally destructive processes of mining or pipelines.
Economically Beneficial
Cost effective: Solar generated electricity is already cheaper than conventional electricity in many major US cities. By 2027, PV will be the most cost-effective solution (even without any government subsidies or advantages from its environmental cleanliness) in nearly all areas of the United States.
Immediate and permanent savings: Properly financed systems will provide consumers with cheaper electricity from the day of installation.
Technological advancements: Improvements in solar technologies offer reduced costs and greater efficiency.
Easily Accessible
Security: The price of solar electricity does not fluctuate with politics or supply speculation; there will never be a shortage that will cause solar electricity to become unaffordable.
Already distributed: There are no expensive transportation costs for solar electricity because the sun shines everywhere.
Leapfrogging: Solar electricity will allow sun-rich developing nations to leapfrog as they are doing with wireless telecommunications to a new energy architecture without having to install expensive land-based grids
Sunday, June 6, 2010
Which Renewable to Power Your House?
Prices have decreased by about a third over the last year because there are so many suppliers now. Chinese solar panel manufacturers have multiplied tenfold over the last year and many are already meeting European standards.
Two years ago, potential buyers would have to ask suppliers if and how many solar panels they might be able to buy. The manufacturers could pretty much set the prices. Now we have a surplus of solar panels.
t’s a good investment for pretty much everyone in Germany--apart from people living in the northwest--because people here produce electricity not for their own consumption needs but for the grid.
The government guarantees a fixed price for solar power that is much higher than what you pay for electricity from non-regenerative sources. Home owners in Germany aren’t interested in energy independence, but selling at a good price.
Many European countries now have similar feed-in tariffs. In southern Europe and northern Africa it also makes sense to use solar for home consumption. And the U.S. is now starting to deploy solar panels on a large scale. California is already a global leader.
We think that on a global scale grid parity could be achieved by 2015, especially in regions with high electricity prices and lots of sun. Solar power should then be able to hold its own without subsidies, even against electricity from natural gas or nuclear power.
In Germany, you should invest before the end of 2010. Electricity from solar panels built before 2011 can be sold at a guaranteed price that will remain stable for 20 years. After that, the guaranteed price will decrease every year.
But there is an interesting paradox. Solar panels are usually more expensive in countries with a lot of sun, because profits would be much higher here otherwise. Even in Germany, solar panels are more expensive in the sunnier south than in the north.
Two years ago, potential buyers would have to ask suppliers if and how many solar panels they might be able to buy. The manufacturers could pretty much set the prices. Now we have a surplus of solar panels.
t’s a good investment for pretty much everyone in Germany--apart from people living in the northwest--because people here produce electricity not for their own consumption needs but for the grid.
The government guarantees a fixed price for solar power that is much higher than what you pay for electricity from non-regenerative sources. Home owners in Germany aren’t interested in energy independence, but selling at a good price.
Many European countries now have similar feed-in tariffs. In southern Europe and northern Africa it also makes sense to use solar for home consumption. And the U.S. is now starting to deploy solar panels on a large scale. California is already a global leader.
We think that on a global scale grid parity could be achieved by 2015, especially in regions with high electricity prices and lots of sun. Solar power should then be able to hold its own without subsidies, even against electricity from natural gas or nuclear power.
In Germany, you should invest before the end of 2010. Electricity from solar panels built before 2011 can be sold at a guaranteed price that will remain stable for 20 years. After that, the guaranteed price will decrease every year.
But there is an interesting paradox. Solar panels are usually more expensive in countries with a lot of sun, because profits would be much higher here otherwise. Even in Germany, solar panels are more expensive in the sunnier south than in the north.
Sunday, May 2, 2010
Build your own Solar System
Our sun is a constant source of energy. Each day, the sun bathes the Earth in unimaginable amounts of solar energy, most of which comes in the form of visible light. All over planet Earth, sunlight is by far the most important source of energy for all living things. Without it, Earth would be lifeless.
Sunlight can be a practical source of energy for such everyday jobs as cooking, heating water, or warming up homes. The challenge is to find ways to transform sunlight into usable heat. The most efficient way to transform sunlight into heat is to shine lots of sunlight onto a dark surface. Dark surfaces absorb most of the visible light that falls upon them, and reflect very little. Visible light that is absorbed this way usually causes the dark-colored surface to warm up. Of all colors, black is able to absorb the most light, and produce the most heat.
You are familiar with what happens to a dark-colored surface when sunlight strikes it: it will get warm. But without a little help, there is usually not enough heat produced to cook foods. To produce enough heat for cooking, it is necessary to shine additional sunlight from a wider area onto the black surface. This is easy to do with mirrors or other reflective surfaces, or with glass or plastic lenses.
The solar oven you will be building from this plan uses aluminum foil to gather sunlight. The foil-covered panels of the oven reflect sunlight into the cooking chamber, which is painted black. Heat is produced when the concentrated sunlight is absorbed by the black surface of the cooking chamber. The heat is contained inside the chamber with the help of insulation and a clear plastic oven bag. The result is a great solar cooker and yummy food!
Safety Precautions:
Use extreme caution when cutting cardboard with the utility knife. Extend the blade only as far as is needed to cut through the cardboard, and lock it into place. Do your cutting on a cutting board or piece of scrap plywood, cardboard, or a kitchen cutting board.
Use sunglasses when working with shiny materials in sunlight.
Solar ovens can get very hot! Use oven mitts or gloves to prevent burns.
President directs initiation of solar energy projects
SLAMABAD: President Asif Ali Zardari has directed the initiation of a pilot project for solar cookers and water heaters in selected areas of the country and has called for devising an easy financing scheme for providing them to the needy and the poor in remote areas.
He said this during a presentation on alternate energy sources at the Aiwan-e-Sadr on Tuesday.
The president directed that state resources be mobilised to develop the energy base of the country in order to overcome the energy shortages that are adversely affecting socio-economic development.
He said being an energy deficient country, all available resources must be utilised effectively to augment the existing capacity so that reliance on conventional resources could be reduced.
Most efficient: Alternate Energy Sources Chief Executive Officer Arif Allauddin said manually-charged devices and solar energy systems were the most efficient technology options for the provision of energy services to remote, off-grid locations in places like NWFP and Balochistan. He said that solar energy was the fastest growing energy technology in the world and as a result the amount of money required to produce solar energy was constantly on the decline.
Countries such as India, China, USA, Spain, Turkey, Germany and the rest of EU were already using solar energy for meeting future energy needs.
The participants were informed that the World Bank was assisting Alternative Energy Development Board (AEDB) in developing an Agricultural Solar Water Pumping Programme for Pakistan and that AEDB had signed two memorandums of understanding (MoU) with leading Chinese companies for solar energy. Zardari directed the relevant ministries to build on the MOUs signed with China and other countries.
The presentation was attended by Federal Minister for Water & Power Raja Pervaiz Ashraf, Minister for Economic Affairs Division Hina Rabbani Khar, SAPM Kamal Majidullah, Secretary General to the president Salman Faruqui, Secretary to the president Malik Asif Hayat and other senior officials of the concerned ministries
He said this during a presentation on alternate energy sources at the Aiwan-e-Sadr on Tuesday.
The president directed that state resources be mobilised to develop the energy base of the country in order to overcome the energy shortages that are adversely affecting socio-economic development.
He said being an energy deficient country, all available resources must be utilised effectively to augment the existing capacity so that reliance on conventional resources could be reduced.
Most efficient: Alternate Energy Sources Chief Executive Officer Arif Allauddin said manually-charged devices and solar energy systems were the most efficient technology options for the provision of energy services to remote, off-grid locations in places like NWFP and Balochistan. He said that solar energy was the fastest growing energy technology in the world and as a result the amount of money required to produce solar energy was constantly on the decline.
Countries such as India, China, USA, Spain, Turkey, Germany and the rest of EU were already using solar energy for meeting future energy needs.
The participants were informed that the World Bank was assisting Alternative Energy Development Board (AEDB) in developing an Agricultural Solar Water Pumping Programme for Pakistan and that AEDB had signed two memorandums of understanding (MoU) with leading Chinese companies for solar energy. Zardari directed the relevant ministries to build on the MOUs signed with China and other countries.
The presentation was attended by Federal Minister for Water & Power Raja Pervaiz Ashraf, Minister for Economic Affairs Division Hina Rabbani Khar, SAPM Kamal Majidullah, Secretary General to the president Salman Faruqui, Secretary to the president Malik Asif Hayat and other senior officials of the concerned ministries
Solar System Pakistan
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n solar system the things you need is depend on what you want to do. If you want to turn on just lights, bulbs or lamps. So then what you need is listed under here.
1. Solar Panel
2. Solar Charge Controller
3. Battery
4. DC Lights
These are things that you must have to turn your lights on. Without them it is difficult to power up lights. Solar system works in this order. Solar Panel is giving current to charge controller. Charge controller charges a battery. And lights are powered up by a battery. In this case it is DC lights.
How Solar Cells Work
You've probably seen calculators with solar cells -- devices that never need batteries and in some cases, don't even have an off button. As long as there's enough light, they seem to work forever. You may also have seen larger solar panels, perhaps on emergency road signs, call boxes, buoys and even in parking lots to power the lights.
Although these larger panels aren't as common as solar-powered calculators, they're out there and not that hard to spot if you know where to look. In fact, photovoltaics -- which were once used almost exclusively in space, powering satellites' electrical systems as far back as 1958 -- are being used more and more in less exotic ways. The technology continues to pop up in new devices all the time, from sunglasses to electric vehicle charging stations.
The hope for a "solar revolution" has been floating around for decades -- the idea that one day we'll all use free electricity fro m the sun. This is a seductive promise, because on a bright, sunny day, the sun's rays give off approximately 1,000 watts of energy per square meter of the planet's surface. If we could collect all of that energy, we could easily power our homes and offices for free.
What hinders solar energy?
ACCORDING to Director General, Board of Investment a solar energy policy would soon be announced hoping that it would open doors for huge investment and lucrative returns in the country. Addressing the office-bearers of the Korangi Association of Trade and Industry he said investors would be encouraged to invest in solar energy plants up to 10 megawatts under the new policy.
The statement of the official indicates that at long last the Government has realised the potential of the solar energy and steps are being contemplated for development and application of this endless source of energy. Pakistan these days is not only facing energy shortage but also the rates of electricity are soaring every now and then making it extremely difficult for a common citizen to pay off monthly electricity bills. As there seems to be no respite in foreseeable future the problems of the consumers can be mitigated by resorting to other methods of generating electricity, solar being one of them. Most of the countries are doing it successfully for decades and their population is benefiting through the use of this free and environment friendly resource. In Pakistan too, some villages have been electrified through solar energy and their inhabitants are not only getting light but also powering fans. Similarly, some companies have introduced solar heaters and geysers but all these experiments are limited to pilot stages and no worthwhile plan has so far been initiated to take advantage of this massive source of energy on the commercial scale. This is despite the fact that we have an Alternative Energy Development Board and a number of countries and companies are keen to invest in the field. We would, therefore, urge the Government not to indulge in rhetoric and take practical measures for development of solar technology in the country, which can help overcome our energy woes to a great extent. Solar power can take care of household energy requirements and the energy so saved could be used for commercial and industrial purposes.
The statement of the official indicates that at long last the Government has realised the potential of the solar energy and steps are being contemplated for development and application of this endless source of energy. Pakistan these days is not only facing energy shortage but also the rates of electricity are soaring every now and then making it extremely difficult for a common citizen to pay off monthly electricity bills. As there seems to be no respite in foreseeable future the problems of the consumers can be mitigated by resorting to other methods of generating electricity, solar being one of them. Most of the countries are doing it successfully for decades and their population is benefiting through the use of this free and environment friendly resource. In Pakistan too, some villages have been electrified through solar energy and their inhabitants are not only getting light but also powering fans. Similarly, some companies have introduced solar heaters and geysers but all these experiments are limited to pilot stages and no worthwhile plan has so far been initiated to take advantage of this massive source of energy on the commercial scale. This is despite the fact that we have an Alternative Energy Development Board and a number of countries and companies are keen to invest in the field. We would, therefore, urge the Government not to indulge in rhetoric and take practical measures for development of solar technology in the country, which can help overcome our energy woes to a great extent. Solar power can take care of household energy requirements and the energy so saved could be used for commercial and industrial purposes.
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