At present, the utilization of solar energy is not very popular. The use of solar power has the problems of high cost and low conversion efficiency, but solar cells have been applied to provide energy for artificial satellites. Solar energy is the energy produced by the continuous nuclear fusion process of sunspots inside the sun or on the surface. The average solar radiation intensity in Earth's orbit is 1,369 w/m2. The circumference of the Earth's equator is 40,000 km, which makes it possible to calculate that the Earth can reach 173,000 TW. The standard peak intensity at sea level is 1kw/m2, and the annual average radiation intensity at a point on the earth's surface at 24h is 0.20kw/m2, which is equivalent to 102,000TW of energy. Humans rely on these energy to survive, including all other forms. Renewable energy (except geothermal energy resources), although the total amount of solar energy is equivalent to more than 10,000 times of the energy used by humans today, the energy density of solar energy is low, and it varies from place to place, and it changes over time. This is development. The main problems facing the use of solar energy. These characteristics of solar energy will limit the role of solar energy engineering in the overall energy system. Although the sun's radiation to the Earth's atmosphere is only one-twentieth of its total radiant energy, it is as high as 173,000 TW, which means that the sun's energy per second is equivalent to 5 million tons of coal per second. The energy that illuminates the Earth is 499,400,00,000 joules. The wind energy, water energy, ocean temperature difference energy, wave energy and biomass energy on the earth are all from the sun; even fossil fuels on the earth (such as coal, oil, natural gas, etc.) are fundamentally stored since ancient times. Solar energy, so the broad range of solar energy is very large, and the narrowly defined solar energy is limited to the direct conversion of solar radiant energy to photothermal, optoelectronic and photochemical.
Solar energy is both primary energy and renewable energy. It is rich in resources and can be used free of charge without transportation and without any pollution to the environment. It has created a new form of life for human beings, enabling society and humanity to enter an era of energy conservation and pollution reduction.