Solar energy is main source of energy in the earth, such as: wind energy, chemical energy, biomass, and hydropower and so on. In this article that we only discuss about solar radiation solar thermal, PV and photochemical direct conversion.
Earth has abundant solar energy resources; the future of solar energy is in bright. At present, the scale of China's solar industry has been ranked first in the world, is the world's solar water heater production and use of the largest countries, and as an important producer of solar photovoltaic cells. Our products are different from the more mature solar: solar photovoltaic systems and solar hot water system. With China's "Renewable Energy Law" the promulgation and implementation of the Kyoto Protocol, the global carbon reduction requirements for conditions to improve, these will have brought great business opportunities to Chinese.
Solar photovoltaic cells is through the photoelectric effect or photochemical effects, convert light directly into electrical energy. The photovoltaic effect to produce many kinds of materials, such as: silicon, amorphous silicon, polycrystalline silicon, gallium arsenide, copper indium selenide. Their power is basically the same principle, is to describe the process of light generation crystal as an example. P-type crystalline silicon doped with phosphorus available N-type silicon to form a PN junction. When the surface of the solar cell when exposed to light, some photons absorbed by silicon material, silicon photon energy transfer to Motoko, the electron transition occurs, a free electron concentration in the PN junction formed on both sides of a potential difference, when connected to an external circuit, under the effect of the voltage, current will flow through the external circuit produces a certain output power. The essence of this process, the photon energy is converted into electrical process.
Currently, the U.S. and Japan divide largest PV market in the world. The United States has the world's largest PV power plant; the power of 7MW, Japan has also built PV power plants, the power output of 1MW. So far, there 230,000 photovoltaic power equipment in the world. Israel, Australia, New Zealand Bureau is among the leader.
Since the 1990s, the global solar battery industry is growth rate of 15% per year and still ongoing sustainable development. According to Dataquest released statistics and forecast report, the United States, Japan and Western Europe, Northern industrialized countries research and development of solar energy in the total investments : 1998 $ 57 billion; 1999 $ 64.6 billion; 2000 $ 70 billion; 2002 is expected to exceeded $ 100 billion.
Our research and development of solar cells attached great importance, as early as during the Seventh Five, and by the silicon semiconductor research work has been included in major national issues, XF and 1995 period, China's focus on the research and development of large-area solar cells and so on. October 2003, the National Development and Reform Commission - Ministry of Science and develop solar energy resources for the next five years development plan, the NDRC "light off the ground" will raise 10 billion for promoting solar power technology, in 2005 the national total installed capacity of solar power generation system up to 300 MW. In 2002, the relevant state ministries launched "western provinces without electricity electrify rural plan", through solar and small wind power solution township seven western provinces without electricity problems. This is a project started, greatly stimulated the domestic solar power industry, the domestic built a few solar cell packaging line, so that the annual production capacity of solar cells increased rapidly. China currently has 10 solar cell production lines with annual production capacity of approximately 4.5MW, including eight production lines are imported from abroad, in which eight production lines, among them, six monocrystalline silicon solar cell production lines, two non- crystalline silicon solar cell production lines.
At present, the domestic solar silicon production enterprises are mainly monocrystalline silicon factory in Luoyang, Hebei and Sichuan Emei ningjin silicon base semiconductor materials factory and other manufacturers, which, Hebei ningjin silicon base is the world's largest solar silicon production, base the world's total solar silicon market share around 25%.
In the solar cell materials downstream market, the current domestic production of solar cells enterprises is: SUNTECH, CEEG, INTERTEK, JA Solar, SOLARFUN, ARTES, TRINA Solar, TIANDA, NB Solar and KYOCERA, a total annual capacity of 800MW or more.
At present, the application of solar cells from the military and aerospace fields, into the industrial, commercial, agriculture, communications, household appliances and utilities sectors, in particular, can be dispersed in remote areas, mountains, deserts, islands and rural areas to use in order to save costly transmission lines. However, at this stage, it costs still high, issue 1KW power need to invest thousands of dollars, so large-scale use is still subject to economic constraints.
The long run, as solar cell manufacturing technology improvements and new photoelectric conversion device invented by countries on environmental protection and the huge demand for renewable clean energy, solar cells will continue to take advantage of solar radiation more practical approach, and industry application of market-based outbreak point is conversion rates and the cost of solar power generation components, Yuan / kWh cost can be reduced to the current cost of purchasing electricity coupled with policy support.