The technology of directly converting solar energy into electric energy is called photovoltaic power generation technology. The international research on photovoltaic power generation technology has a history of 100 years. At present, this high-end energy product has matured. China began to study solar cells in 1958, and it was successfully applied to the "Dongfanghong" 2 satellite launched by China for the first time in 197 1. 1973, solar cells were used on the ground. In 2002, the relevant state departments started the "Power Transmission into Villages Project" and installed photovoltaic power stations in nearly 800 villages and towns in seven western provinces, which promoted the rapid development of photovoltaic industry in China. By the end of 2004, the cumulative installed capacity of solar cells in China has reached 65,000 kilowatts.