Solar energy is considered to be one of the best choices for mankind to replace traditional fossil energy in the 21st century. It is a renewable green energy. Solar energy, a kind of clean energy, is more and more favored by people, and it has a wide range of roles in people's life and work. One of them is to convert solar energy into electric energy, and solar cells use solar energy to work. The working principle of a solar thermal power station is to use the concentrated sunlight to boil water and turn it into water vapor, which is then used to generate electricity. What I want to introduce next is some related content of solar thermal power generation.

Solar thermal power generation converts solar energy into thermal energy first, and then converts thermal energy into electrical energy. It has two conversion methods. One is the direct conversion of solar thermal energy into electrical energy, such as thermoelectric power generation of semiconductors or metal materials, thermal electron and thermoelectric ion power generation in vacuum devices, alkali metal thermoelectric conversion, and magnetic fluid power generation. Another way is to use solar thermal energy through a heat engine (such as a steam turbine) to drive a generator to generate electricity, which is similar to conventional thermal power generation, except that the heat energy does not come from fuel, but from solar energy. At present, solar thermal power generation in the world mainly includes tower, trough, dish and Fresnel types. At present, many countries in the world are planning or constructing solar thermal power stations, and my country is also actively planning to build some solar thermal power stations.

The trough-type solar thermal power generation system is called trough-type parabolic reflector solar thermal power generation system, which is to arrange multiple trough-type parabolic concentrating heat collectors in series and parallel to heat the working fluid, generate superheated steam, and drive the turbine generator set to generate electricity. The dish type (also known as the disc type) solar thermal power generation system (parabolic mirror Stirling system) is composed of a parabolic mirror composed of many mirrors. It is received at the focal point of the parabola, and the heat transfer working medium in the receiver is heated to At around 750°C, it drives the engine to generate electricity. Fresnel-type CSP is similar to trough-type CSP, except that the condenser with Fresnel structure is used instead of the parabolic mirror. This makes its cost relatively low, but the efficiency is correspondingly reduced. Because this type of system has only tens of times the light concentration, the quality of the heated water vapor is not high, so that the annual power generation efficiency of the entire system can only reach about 10%; but due to the simple structure of the system, the direct use of heat transfer medium to generate steam, etc. Its construction and maintenance costs are also relatively low. The tower-type solar thermal power generation system is to build a tall central absorption tower on the open ground. An absorber is installed and fixed on the top of the tower. A certain number of heliostats are installed around the tower. The sun is concentrated on the top of the tower through the heliostats. The cavity of the receiver generates high temperature, which is heated by the working fluid of the absorber and generates high-temperature steam, which drives the steam turbine to generate electricity. These CSP methods all convert light into heat and then generate steam to drive steam turbines to generate electricity. Regardless of the method of power generation, how to store energy is the most critical one. Just like photovoltaics, it can only generate electricity during the day. The electricity generated during the day cannot be used, and the electricity cannot be supplied at night. This not only causes a waste of resources, but also The power grid has not played any mitigating effect. Therefore, energy storage is essential in the power generation process. How to store energy is the key. At present, the most ideal is molten salt energy storage. As the core technology of solar thermal power generation, currently only a few countries in the world master this technology, the United States, Spain, Denmark, and Germany.

Solar thermal power generation is bound to flourish in the world!