Solar panels can convert thermal energy directly into electricity.
Solar power generation methods There are two solar power generation methods: one is the light-heat-electricity conversion method and the other is the light-direct conversion method. electricity.
1. The light-heat-electricity conversion method uses thermal energy generated by solar radiation to produce electricity. Generally, a solar collector converts the absorbed thermal energy into steam as the working fluid, and then drives a working fluid. steam turbine to produce electricity. The first process is a process of converting light into heat; the second process is a process of converting heat into electricity.
2. The direct light-to-electricity conversion method uses the photoelectric effect to directly convert solar radiation energyin electrical energy. The basic device for converting light into electricity is the solar cell.
Monocrystalline silicon solar panels:
The photoelectric conversion efficiency of monocrystalline silicon solar panels is about 15%, with the highest reaching 24%. This is the highest photoelectric conversion efficiency among all types. of solar panels. The most effective, but the production cost is so high that it cannot be widely and commonly used in large quantities.
Since monocrystalline silicon is usually encapsulated in tempered glass and waterproof resin, it is strong and durable, with a lifespan of typically up to 15 years and up to 25 years.
Reference for the above content: Baidu Encyclopedia - Solar Panels
Can solar panels directly convert thermal energy into electrical energy?
As we all know, solar energy is a widely used clean energy source. Places like Lhasa, China are covered in solar panels that people can use. While everyone is enjoying the comfort and cleanliness that solar energy brings, many scientists have raised questions. Is solar energy really a clean energy source?
When we talk about solar energy, we must mention our tool for obtaining solar energy - the solar panel. There is no doubt that solar panels do not emit greenhouse gases like carbon dioxide when they produce electricity. It is for this reason that clean energy sources such as solar power are favored by those who are concerned about energy consumption and greenhouse gas emissions, thereby harming the environment.
But we all know that silicon is mentioned inhigh school chemistry textbooks as an important component of solar panels. Manufacturing solar panels itself requires a lot of effort. Solar panels use silicon to absorb and convert sunlight, and melting and purifying silicon in particular requires large amounts of heat. The melting point of silicon is 1414°C, only 124°C lower than that of iron. Meanwhile, silicon is melted in electric furnaces and most electricity is produced by burning fossil fuels. This means that a large amount of carbon dioxide is emitted during the manufacturing process of solar panels. As a result, some scientists point out that new solar panels already carry a “carbon debt” before they are even put into service. From the point of view of reducing greenhouse gases, it is necessary to repay the carbon debte before the panels become part of the solution (rather than the problem).
Scientists published in Nature Communications have calculated the energy needed to make all the solar panels installed worldwide between 1975 and 2015, as well as the carbon dioxide emissions generated by producing that energy. They also looked at the energy generated by installing the panels and the amount of carbon dioxide released into the atmosphere. Although China relies more on fossil fuels to generate electricity, greenhouse gas emissions from manufacturing a panel in China are almost twice as high as in Europe, but this can allow China to save a lot of electricity generated by burning fossil fuels. After comparing the two, it was found that the environmental benefits of installing solar panels in China are greater than those ofe Europe.
After completing their research, these scientists discovered that currently produced solar panels would emit on average about 20 grams of carbon dioxide per kilowatt hour over their lifetime (regardless of when they have been produced, approximately 30 years). ). This number was 400 to 500 grams in 1975. Likewise, the time required for a solar panel to generate the energy consumed during its manufacture has fallen from around 20 years to two years or even less.
Although emissions of greenhouse gases such as carbon dioxide have been significantly reduced, this does not mean that they have been completely eliminated. Some even point out that our use of solar energy should be taxed like other energy sources that emit greenhouse gases. But at the same time, some object that if we care about everything, we cannot talk about clean energy.
Although there isthere is an extensive debate on this issue in society, the editor believes that we do not need to worry too much about these so-called greenhouse gases generated during the manufacturing process, but we should focus on economic benefits. provided by these clean energy sources. After all, as global technology advances, we will certainly reduce greenhouse gas emissions and make our planet cleaner.
Solar panels can directly convert thermal energy into electrical energy.
Solar power generation methods There are two solar power generation methods: one is the light-heat-electricity conversion method and the other is the light-direct conversion method. electricity.
(1) The light-heat-electricity conversion method uses thermal energy generated by solar radiation to produce electricity. GeneralBasically, a solar collector converts the absorbed thermal energy into steam as the working fluid and then drives it away. a steam turbine to produce electricity. The first process is a process of converting light into heat; the second process is a process of converting heat into electricity.
(2) The direct light-to-electricity conversion method uses the photoelectric effect to directly convert solar radiation energy into electrical energy. The basic device for converting light into electricity is the solar cell.
According to currently known technology, only photovoltaic solar panels can directly convert the sun's radiant heat into electrical energy. Thermoelectric conversion materials directly convert thermal energy into electrical energy. It is an all-solid-state energy conversion method that does not require reactions cchemicals or fluids.
Therefore, there is no noise, no wear, no fluid leakage and no volume during the power generation process. With the advantages of small size, light weight, easy movement and long service life, it occupies an "irreplaceable" position in special application fields such as military batteries and l long-range space. sensors, long-distance communications and navigation, and microelectronics.
Detailed information:
Composition of the solar panel and functions of each part:
(1) Tempered glassGlass: Its function is to protect the main power generating body (such as battery cells). There are requirements for its light transmission selection:
(2) EVA: Used for bonding and fixing tempered glass. and the main power generation body (battery cells). The qualityTee of transparent EVA material directly affects the life of the component. EVA exposed to air is prone to aging and yellowing, thereby affecting the light transmission of the component and thus affecting. the energy production quality of the component. In addition to the quality of the EVA itself, the component manufacturer's lamination The impact of the process is also very significant, for example, if the bonding degree of the EVA does not meet standards. the bonding strength between EVA, tempered glass and backplane is insufficient, it will cause premature aging of EVA and affect the service life of components.
(3) Cells: The main function is to produce electricity. The main market for power generation is crystalline silicon solar cells and thin-film solar cells, both of which have their own advantages and disadvantages.
Silicon solar cellsm crystalline have relatively low equipment costs, but high consumption and cell costs. However, the photoelectric conversion efficiency is also high, and they are more suitable for generating electricity under outdoor sunlight.
Thin film solar cells have relatively high equipment costs, but the consumption and battery costs are very low, but the photoelectric conversion efficiency is more than half of that of cells made of crystalline silicon, but the low light effect is very good, under ordinary light. Can also produce electricity, like solar cells in a calculator.
(4) Back plate: Function, sealing, insulation and waterproofing. Typically, TPT, TPE and other materials are used and must be resistant to aging. Most component manufacturers offer a 25-year warranty. The verre hardened and aluminum alloy generally pose no problem. .
(5) Aluminum alloy: protects rolled parts and plays a certain sealing and supporting role.
(6) Junction box: Protects the entire power generation system and acts as a power transfer station. If any component is shorted, the junction box will automatically disconnect the shorted battery string to avoid burning. of the entire system. The most critical thing in the junction box is the selection of diodes depends on the type of cells in the module, and the corresponding diodes are also different.
(7) Silica gel: sealing function, used to seal the junction between components and aluminum alloy frames, components and junction boxes. Some companies use double-sided tape and foam to replace silica gel. commonly used in China.The process Simple, practical, easy to use and inexpensive.
Baidu Encyclopedia-Solar Panels