The depletion of oil almost like a mantra, has brought anxiety to humans. What is oil and other non-renewable energy alternatives » Recently, the United Kingdom, "New Scientist" announced that, after years of scientific research, solar energy is not far off when the era.
The most effective and broad prospects for most of the plastic photovoltaic cell technology, once the technology is mature, we can print newspapers like the same production photovoltaic cells. Our goal is to reach 10 percent conversion rate, and ultimately will exceed the target
Theoretically, the world's energy solution to the problem is very simple. To find a sunny place, as long as half of Qinghai Province so great, and then try to use where the sun's energy, as long as able to use its 20 per cent, then the issue was resolved - you already have enough power to meet the energy needs of the world , And this inexhaustible supply of electricity is the most clean.
？ There are so simple? » Over the years, whenever the solar energy technology made little progress, people cheered Association that the new revolution here. However, these revolutions have ended in failure every time, mainly because of solar energy technology is too expensive and and nuclear energy, wind power and other alternative sources of energy output compared with low efficiency, did not have sufficient funds to launch large-scale solar energy conversion. Recently, things are different. The political will, economic pressures and technological progress in working together, we are about to usher in an era of solar energy.
The traditional use of solar energy technology
High oil prices, people generally recognized that oil the damage caused to the environment, the solar cell industry investment into the Hurricane process, the efficiency of solar cells enhance stability, all these factors make us use the sun to meet the electricity demand of all the world -- 2005 is a conservative estimate of 150 million kwh - the desire to finally become a reality.
The most widely used solar energy technology is the condenser system. Rows of condenser at the sun, it's full of energy gathered in the liquid (such as oil or water) pipeline. Then liquid heated to about 400 degrees Celsius, the promotion of traditional steam turbine generators. Condenser system will be able to capture the sun heat it for about 20 percent into electricity, and almost certain commercial photovoltaic cells, but the cost is much lower in comparison.
In the 1980s, the U.S. Nevada desert has built nine solar concentrators manor, which was the total area of one square kilometers, the installed capacity of 354,000 kilowatts. These solar Manor had an expansion plan, but in the early 1990s, because oil prices are low, the plan has not been implemented, but they continue to transfer power to local power grids. Now rising oil prices, these plans has once again been filed. December 2005, since 1988 the United States since the first condenser system in Arizona, announced the completion of its installed capacity of 1,000 kilowatts.
Other traditional solar power generation technologies, including Spain's sunny California, the tower and disk mirror. The former solar energy utilization rate is about 15 percent, which is about 24 percent. Last year, Spain invest in the construction of the second tower blocks sunlight, installed capacity of 20,000 kilowatts. California in the desert state of the construction of 20,000 disk mirror, after the completion of installed capacity will reach 500,000 kilowatts.
Photovoltaic cell technology
1954, the United States of Bell Labs invented the first one photovoltaic cells; Since then, battery energy into electricity to the efficiency of the technology has been a weakness. The root of the problem lies in the way photovoltaic cells operate. All of photovoltaic cells are semiconductor materials in essence, each by a photon of the impact, it will release an electronic. Scientists try to allow these current electronic form.
The impact of this semiconductor photon carried by the sun's energy is not the same, not all photon can stimulate electronic.
Bell Labs found that the most suitable for silicon in the sunshine of photon energy spectrum. Even so, they created the first battery of a conversion rate of only 6%. In the following for a very long time, the technology has been very slow progress, the transformation can only achieve the highest rate of more than 10%, but the cost is very high, can only put military or aerospace use. But over the past decade technology has made great progress in the commercialization of photovoltaic cells conversion rate can reach 20 percent, the conversion rate of the laboratory is even higher.
Last year,and his colleagues at the University of Delaware broke the record, they designed photovoltaic cells of energy conversion rate of 42.8 percent. Barnett said that in the near future, the conversion rate of 50 percent of the photovoltaic cells will enter the commercial field. Their design and modern production technology combined with means that the cost of using solar power has been rapidly declining.
Aachen in the German solar industry analyst Michael Luo Geer pointed out that as the research results, the highest in the world price of (parts of Japan, the United States, California and Italy), the cost of solar power has been close to Even the equivalent of natural gas and nuclear power generation costs. For instance, in the United States, the average price (the traditional way power generation) is 10 cents per unit, while the cost of solar power has dropped to almost 20 cents per unit. This makes photovoltaic cells market has been vigorous development - now an annual growth of about 35 percent - of private investors have begun to generate strong interest. For the main business of solar energy to the company's stock market value in January 2006 only 40 billion U.S. dollars, has now grown to over 140 billion U.S. dollars, which makes solar energy as the world's fastest growing areas of the market.
U.S. President George W. Bush has allocated 168 million U.S. dollars of U.S. federal funding of solar innovation plan, the research project's goal is to reduce the cost of photovoltaic power generation technology, so that in 2015, and other energy technologies can be a higher low. Luo Geer believes that Bush's goals can be achieved. He said the cost of manufacturing photovoltaic equipment has dropped significantly, in some places, the use of photovoltaic technology has the power to be cheaper than conventional electricity. The cost of manufacturing photovoltaic cells per watt power generation capacity is a dollar, the cost in any place should be competitive.
The use of photovoltaic cells Status
In this revolution in the Sunshine State is leading Germany. November 2003, as oil and gas prices soaring, more and more serious global warming, the German parliament approved a "feed tax" plan, the plan to open up a vast solar energy market. Anyone who use solar power, we will be able to sell electricity issued by the State Grid, the price for each of the 45 to 57 cents a share, which is almost three times the market price - per unit of electricity consumers to pay 19 U.S. Points. German legal provisions of the power company in 2024 prior to the acquisition in accordance with the residents issued by the use of solarpower. The scheme so that a large number of German investment has generated interest in solarpanels. Today, the German photovoltaic power generation system has more than 300,000 sets. This allows Germany as the world's fastest-growing photovoltaic power generation market. The world has already been installed on board the PV cells are 55 percent in Germany, the use of solarpower each year to 3 billion watts, equivalent to 3-5 conventional power plants.
Italy and Spain in the last year, following the footsteps of Germany, also issued their "feed tax" programme; U.S. plans to promote solarenergy in California has invested 2.8 billion U.S. dollars in cash to fund the newly installed photovoltaic power generation systems, assessed per watt down A subsidy of about 2.5 U.S. dollars. Luo Geer forecast to 2008, there will be 20 countries have enacted the same revenue options.
It is hoped that by stimulating demand, these subsidies will stimulate the photovoltaic technology research and related materials manufacturing technology, photovoltaic power generation costs will be reduced.This may help speed up the already existing photovoltaic technology development, but also may be the industry Bijin dead end, because the use made of silicon photovoltaic cells board will soon reach the conversion of the theoretical limit - about 30 %. However, Australia's University of New South Wales Madinggelin that it is possible to use other materials to limit conversion rate of 74 percent of the photovoltaic cells. And despite these subsidies from certain in terms of stimulating the market, but most analysts believe that the existing photovoltaic cells or the cost is too high, can not become the mainstream.
The dawn of new technology
So many researchers began looking for other alternatives. The most expensive film photovoltaic cells are batteries, film batteries only the size of traditional photovoltaic cells volume of 1.0%, and its band gap can be adjusted through the film contained in the proportion of components and improved. For example, one from copper, indium, gallium and selenium mixture of batteries are cheap, but in laboratory experiments, the conversion rate it has been able to reach around 19 percent.
In addition, through the filter or nano-crystals (nanocrystals) to improve the conversion rate method. But the most effective and most broad prospects for the plastic photovoltaic cell technology. University of California, Santa Barbara Yi Lunxi McNair and colleagues developed a conductive plastic can. This plastic and silicon semiconductor and other materials, like photovoltaic cells, to allow the release of e-photon. July this year, Seagate has successfully developed a conversion rate of 6.5 percent of plastic photovoltaic cells, setting a new record.
Seagate, plastic photovoltaic cells really attractive is that if the technology is mature, we can print newspapers like the same production photovoltaic cells. "Our goal is to reach 10% of the conversion rate, and ultimately will exceed the target," he said, but he and step conversion problems. "The key factor is how many dollars per watt," he said, "Even if our conversion rate lower than silicon, but the cost per watt, we still take advantage of, because of its extremely low cost of production."
Perhaps the prospect of using solar photovoltaic cells on the plastic. This is a long and slow revolution, but after many years of tireless research, coupled with a genuine confidence in the start of the allocation of investment, solar energy era has finally arrived.