Solar photovoltaic power generation equipment is required to have sunlight to generate electricity, because the energy it uses comes from sunlight, but there will be no sunlight at night, so this makes the power generation capacity of solar and photovoltaic power generation equipment extremely unbalanced in time distribution, but the electricity consumption at night is also quite large, which is also a major obstacle to limiting solar photovoltaic power generation.
However, according to a news report reported by China News Network on April 10, a paper was published in the semi-monthly magazine of applied physics communications in the United States published on April 5, and scientists and engineers from Stanford University designed a solar panel that can generate electricity at night, which is expected to solve the problem that solar photovoltaic power generation equipment cannot generate electricity at night.
The solar panel looks nothing special because its material is not special in the first place, but in addition to the panel that absorbs sunlight, it is attached with an insulating material called a "thermoelectric module" (TEG and a unique material that can capture thermal wavelengths), in addition to an embedded thermoelectric generator (TEG), which can work at night and "draws electrical energy from the temperature difference between the photovoltaic cell and the surrounding environment".
The leader of this invention is Fan Shanhui, an electrical engineer at Stanford University, who explained that the newly invented solar photovoltaic cells have two materials, ordinary photovoltaic materials can receive sunlight today to generate electricity, and thermoelectric module insulation materials can absorb the heat flow radiated outward by photovoltaic cells at night, which will enable it to generate current. Therefore, this technical principle is not difficult to understand, photovoltaic power generation equipment can absorb sunlight during the day while storing light energy heat, and then radiate heat outward through the radiator at night, and a large part of these energy can be captured by the thermoelectric module.
Experts believe that this kind of power generation equipment is very suitable for installation in areas with large temperature differences between day and night, such as the northwest region of the mainland and the Qinghai-Tibet Plateau, the direct sunlight during the day can be very sufficient, and the air temperature at night is very low, and the regional environment is very conducive to the efficiency of this power generation equipment. The mainland is the world's largest producer of solar panels and the largest country in solar power generation, so this technology may be of great significance to the development of the continent's solar energy industry.
After the publication of the paper, the technology has been considered a breakthrough in the field of solar photovoltaic power generation, but the current power generation equipment at night produces very little power, the power generated at night is only 50mW per square meter (milliwatt), driving a 100-watt bulb requires tens of square meters of solar panels, so it is basically difficult to use effectively, and the standard solar panel is about the ideal state of power generation during the day, the power is about 1000W (watts) per square meter, Day and night power generation can not be compared at all, and at night when the heat stored in photovoltaic power generation cools relatively fast, the electricity generated by this technology will decay quickly until there is no electricity, so although this invention is amazing, this is still far from practical application.
However, the inventor believes that the current design is still just an attempt, there is a lot of room for improvement, and its power generation efficiency at night will also be greatly improved in the future.
Resources:
"Global Network" April 6 article "The advent of a new type of solar panels: night can also generate electricity"