Solar water heaters, solar street lights, solar batteries, etc. are all inseparable from energy from celestial bodies outside the earth-solar energy. The development of solar energy mainly includes the following aspects: Light and heat utilization: It is basically to collect solar radiant energy and convert it into heat energy for utilization through interaction withmatter. Currently, the most commonly used solar collectors include three types: flat-plate collectors, evacuated tube collectors and focused collectors. Generally, solar thermal utilization is divided into low-temperature utilization (<200℃), medium-temperature utilization (200-800℃) and hightemperature utilization (>800℃) according to the different temperature and application that can be reached.At present, lowtemperature applications mainly include solar water heaters, solar dryers, solar distillers, solar houses, solar greenhouses, solar air- conditioning refrigeration systems, etc., medium-temperature applications mainly include solar cookers, solar thermal power generation concentrating heat collection devices, etc., high-temperature applications mainly include high temperature Sun furnace and so on.
Photochemical utilization: This is a photo chemical conversion method that uses solar radiation energy to directly split water to produce hydrogen. Solar power generation: Large- Light-heat-scale utilization of solar energy in the future will be used to generate electricity. There are many ways to use solar power. At present, there are mainly the following two types that are practical electric conversion.That is, the heat generated by solar radiation is used to generate electricity.Generally, a solar collector is used to convert the absorbed heat energy into steam of the working fluid, and then the steam drives a gas turbine to drive a generator to generate electricity.The former process is light-heat conversion, and the latter process is heat-electric conversion. Light-electric conversion. Its basic principle is to use the photovoltaic effect to directly convert solar radiant energy into electrical energy, and its basic device is a solar cell.
Photobiological utilization: the process of converting solar energy into biomass through photosynthesis of plants. At present, there are mainly fast-growing plants (such as firewood), oil crops and giant seaweeds.Although the total amount of solar energy resources is equivalent to more than 10,000 times the energy used by human beings, the energy density of solar energy is low, and it varies from place to place and changes with time. This is the main problem facing the development and utilization of solar energy.
