I understand the difference between solar thermal power generation and photovoltaic power generation

Photovoltaic power generation is a technology that directly converts light energy into electrical energy by utilizing the photovoltaic effect of the semiconductor interface. It is mainly composed of three parts: solar panel (component), controller and inverter. The main components are composed of electronic components. The solar cells are packaged and protected in series to form a large-area solar cell module, and then combined with a power controller and other components to form a photovoltaic power generation device.

The main principle of photovoltaic power generation is the photoelectric effect of semiconductors. When a photon is irradiated onto a metal, its energy can be completely absorbed by some electron in the metal. The energy absorbed by the electron is large enough to overcome the internal gravity of the metal and escape from the metal surface to become photoelectron. A silicon atom has four outer electrons. If five atoms of outer electrons, such as phosphorus atoms, are doped into pure silicon, they become N-type semiconductors; if pure silicon is doped with three outer electrons, such as A boron atom forms a P-type semiconductor. When the P-type and the N-type are combined, the contact surface forms a potential difference and becomes a solar cell. When the sunlight hits the P-N junction, the holes move from the P-pole region to the N-pole region, and the electrons move from the N-pole region to the P-pole region to form a current.

The photoelectric effect is a phenomenon in which light causes a potential difference between a heterogeneous semiconductor or a different portion where a semiconductor and a metal are combined. It is first a process in which photons (light waves) are converted into electrons, and light energy is converted into electric energy; secondly, a voltage process is formed.

After the polycrystalline silicon is ingot, broken ingot, sliced, etc., it is made into a silicon wafer to be processed. A P-N junction is formed by doping and diffusing a trace amount of boron, phosphorus, or the like on the silicon wafer. Then, by screen printing, the fine silver paste is printed on the silicon wafer to form a grid line, which is sintered and simultaneously formed into a back electrode, and an anti-reflection coating is applied on the surface of the gate line, and the battery sheet is Made to date. The cell array is combined into a battery pack to form a large circuit board. Generally, an aluminum frame is wrapped around the assembly, the front cover glass, and the reverse side mounts the electrode. With battery components and other ancillary equipment, you can form a power generation system. In order to convert direct current to alternating current, a current converter is required. It can be stored in the battery after power generation, or it can be input into the public power grid. Among the cost of power generation systems, battery components account for about 50%, current converters, installation costs, other auxiliary components, and other expenses account for another 50%.

1 no danger of exhaustion;

2 safe and reliable, no noise, no pollution, absolutely clean (no pollution);

3 Not limited by the geographical distribution of resources, the advantages of building roofs can be utilized; for example, areas without electricity, and areas with complex terrain;

4 It can generate electricity on site without consuming fuel and erecting transmission lines;

5 high energy quality;

6 users are emotionally acceptable;

7 The construction period is short, and the time taken to obtain energy is short.

1 The energy distribution density of the irradiation is small, that is, it takes up a large area;

2 The energy obtained is related to meteorological conditions such as four seasons, day and night and cloudy.

3 At present, compared with thermal power generation, generators will cost a lot.

4 The photovoltaic panel manufacturing process is not environmentally friendly.

Solar thermal power generation refers to the use of large-scale array parabolic or dish-shaped mirrors to collect solar thermal energy, provide steam through heat exchange devices, and combine the technology of traditional steam turbine generators to achieve power generation.

The use of solar thermal power generation technology avoids the expensive silicon crystal photoelectric conversion process and can greatly reduce the cost of solar power generation. Moreover, this form of solar energy utilization has an advantage over other forms of solar energy conversion, that is, the hot water of solar energy can be stored in a huge container, and still can drive steam turbines for several hours after the sun sets. .

The principle of solar thermal power generation is to collect sunlight into a solar energy collection device through a mirror, and use solar energy to heat the heat transfer medium (liquid or gas) in the collection device, and then heat the water to form steam to drive or directly drive the generator to generate electricity.