Solar energy and its Utilization

Solar energy is one of the new energy. It comes from nuclear fusion inside the sun, a massive source of energy that is inexhaustible. Although solar energy is renewable, abundant, free of charge and causing no environmental pollution, its utilization is limited due to the low density of energy flow, and the restrictions of seasonal, geographic and weather conditions.  

The utilization of solar energy was firstly merely limited to basking grains etc, but now has widely expanded, mainly including  the using of heat and light, photoelectricity and photochemistry, such as solar battery, greenhouse, solar hot-water system, solar heating and cooling system, etc.. It is planned that by 2020,  the capacity of solar power generation will reach at 2000MW, solar water-heater will cover about 300 millions sq. meter, and the annual fuel energy to be substituted will be up to 40 million tons of standard coal.