? Solar energy is the sun's nuclear fusion reactions within the continuous energy generated. Earth orbit nike roshe run saldi , the average solar radiation intensity 1367kwm2. Earth's equatorial circumference to 40000km, and thus calculated the Earth's energy was up to 173,000 TW. At sea level standard peak intensity 1kwm2, a point on the earth's surface 24h, the average radiation intensity 0.20kwm2, the equivalent of a 102,000 TW of energy, human survival depends on these energies, including all other forms of Renewable Energy (Except for geothermal energy resources) Although the total amount of solar energy resources is the human equivalent of energy used by ten thousand times, but the solar energy density is low, and it vary, as time changes, which is facing the development and utilization of solar energy major problem. These characteristics make it solar integrated energy system in the role of subject to certain restrictions. Sun is a huge, long nike air max 90 italia , endless energy. Although the solar radiation energy to the Earth's atmosphere is only the total radiation energy (about 3.75 ? 1026W) 2.2 billion to one, but up to 173,000 TW, that sun exposure to the earth per second is equivalent to the energy 5 million tons of coal. The figure is the planet's energy flow diagram. As can be seen from the chart, earth wind energy, hydropower, ocean thermal energy, wave energy and biomass and some solar tidal energy comes from; even the earth of fossil fuels (such as coal, oil, natural gas ) basically said that since the store is down the ancient solar energy, it covered a broad range of solar energy is very large, narrow solar energy is limited to solar radiation, solar thermal, photovoltaic and photochemical direct conversion. Earth energy flow diagram (unit 106MW) Solar energy is an energy adidas springblade offerta , is renewable energy. It is rich in resources, both free, then no transport, no pollution on the environment. However, there are two main solar disadvantages: First, energy density is low; Second, its strength due to various factors (season, location, climate, etc) can not maintain a constant effect. These two drawbacks greatly limit the effective use of solar energy. Human use of solar energy has a long history. In the early years of the Warring States period in 2000 knew of four steel mirror to focus sunlight ignition; use of solar energy to dry agricultural products. To the modern, solar energy has become increasingly widespread, it includes the use of solar light and heat, solar photovoltaic and solar energy use photochemical utilization. 1.2 Structure of the Sun Sun is a hot gaseous sphere, its diameter is about 1.39 ? 106km adidas pro conference hi blu , a mass of about 2.2 ? l027t, the quality of the Earth 3.32 ? 105 times larger than the earth in volume, 1.3 ? 106 times the average density of the Earth 1 4. The main component gases of hydrogen (about 80%) and helium (about 19%). Within the sun is going with hydrogen into helium fusion reaction polymerization, has continued to release tremendous amounts of energy, and in the way of radiation and convection heat transfer from the core to the surface temperature also decreased gradually from the center to the surface. Known by the nuclear fusion of hydrogen into helium in the aggregate, while the release of enormous energy, the quality of the loss of 0.00729 per 1g. Under the current estimated