Solar energy is considered one of the choices for humans to replace traditional fossil fuels in the 21st century, and it is a renewable green energy source. Solar energy, as a clean energy source, is increasingly favored by people and has a wide range of functions in their daily lives and work. One of them is to convert solar energy into electrical energy, and solar cells work using solar energy. The working principle of a solar thermal power station is to use the concentrated sunlight to boil water into steam, which is then used to generate electricity. What I am going to introduce next is some related content of solar thermal power generation.

Solar thermal power generation first converts solar energy into thermal energy, and then converts thermal energy into electrical energy. It has two conversion methods. One method is to directly convert solar thermal energy into electrical energy, such as temperature difference power generation in semiconductors or metal materials, 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, similar to conventional thermal power generation, except that its thermal energy does not come from fuel, but from solar energy. At present, there are several types of solar thermal power generation in the world, including tower type, trough type, disc type, and Fresnel type. Currently, many regions in the world are planning or constructing solar thermal power stations, and China is also actively planning to build some solar thermal power stations.

The trough solar thermal power generation system, also known as the trough parabolic reflector solar thermal power generation system, is a series parallel arrangement of multiple trough parabolic concentrating collectors that heat the working fluid, generate superheated steam, and drive the turbine generator set to generate electricity. The dish type (also known as the dish type) solar thermal power generation system (parabolic reflector Stirling system) is composed of many parabolic reflectors, which are received at the focal point of the parabolic surface. The heat transfer medium inside the receiver is heated to around 750 ℃, driving the engine to generate electricity. Fresnel type solar thermal power generation is similar to trough type solar thermal power generation, but uses a Fresnel structured condenser lens instead of a parabolic mirror. This makes its cost relatively low, but its efficiency also decreases accordingly. Due to the fact that the concentration factor of this type of system is only tens of times, the quality of the heated water vapor is not high, resulting in an annual power generation efficiency of only about 10% for the entire system; However, due to its simple system structure and direct use of thermal conductive media to generate steam, its construction and maintenance costs are relatively low. The tower solar thermal power generation system is a tall central absorption tower built on an open ground, with a fixed absorber installed on the top of the tower and a certain number of solar mirrors installed around the tower. The solar light is concentrated in the receiver cavity at the top of the tower through the solar mirrors to generate high temperature, which is then heated by the working fluid of the absorber and generates high-temperature steam to drive the steam turbine to generate electricity. These types of solar thermal power generation methods all generate electricity by converting light into heat and generating steam to drive a steam turbine. Regardless of the power generation method, how to store energy is crucial, just like photovoltaics, which can only generate electricity during the day. The electricity generated during the day cannot be used, and electricity cannot be supplied at night. This not only causes resource waste, but also does not have any mitigating effect on the power grid. So, energy storage is crucial in the process of power generation. How to store energy is key, and currently the ideal solution is molten salt energy storage. As the core technology of solar thermal power generation, currently only the United States, Spain, Denmark, and Germany have mastered this technology globally.

Solar thermal power generation will surely flourish in the world!