Solar power is the energy generated by the continuous fusion reaction of sunspots within or on the surface of the sun. The average solar radiation intensity in the Earth's orbit is 1367w/㎡. The circumference of the Earth's equator is 40000km, thus calculating that the earth can obtain up to 173000TW of energy. The standard peak strength at sea level is 1kw/㎡, and the average annual radiation intensity of 24h on the Earth's surface is 0.20kw/㎡, equivalent to 102000TW of energy, which humans rely on to sustain survival, including all other forms of renewable energy (except geothermal resources), Although the total amount of solar energy is equal to 10,000 times that of human resources, solar energy density is low, and it varies from one place to the other, which is the main problem in the development and utilization of solar energy.
These characteristics of solar energy will make it in the overall energy system in the role of a certain limit. Although the energy emitted by the sun to the Earth's atmosphere is only 2.2 billion of its total radiation energy, it is up to 173,000TW, which means that the sun's energy on Earth is equivalent to 5 million tons of coal per second. The wind on Earth, water energy, ocean temperature difference energy, wave energy and biomass energy, as well as some tidal energy are from the sun; even the fossil fuels on earth (coal, oil, natural gas, etc.) are fundamentally the solar energy stored in the past, so the broad range of solar power is very large,
The narrow sense of solar energy is limited to the solar radiant heat, photoelectric and photochemical direct conversion. Solar energy, commonly referred to as the radiant energy of sunlight, is generally used as a power generation in modern times. Since the Earth's formation of life mainly with the sun to provide heat and light to survive, and since ancient times, people also know to sun-dried objects, and as a way to preserve food, such as salt and dried salted fish and so on. But with the reduction of fossil fuels, it is intended to further the development of solar energy. The use of solar energy has passive use (light and heat conversion) and photoelectric conversion of two ways. Solar power is a new renewable energy. The broad sense of solar energy is the source of many of the Earth's energy, such as wind, chemical energy, water and other potential energy.