The main factors affecting the power generation of photovoltaic power plants
The power generation of a photovoltaic power station not only depends on the power generation performance of the photovoltaic power station itself, but also is closely related to the later operation and maintenance. Correct operation and maintenance can not only increase the power generation, but also greatly improve the service life of the equipment and power station.
Let’s discuss the main factors affecting the power generation of photovoltaic power plants and how to improve the power generation of photovoltaic power plants.
The following table lists the main factors that affect the power generation of photovoltaic power plants. Obviously, from the point of view of power station design and construction, it is necessary to do a good job in PV series-parallel connection, reduce the short board error of the module series, select high-efficiency inverters, step-up transformers, optimize the lines in the station, select appropriate cables, avoid module shading, maintain Ventilation and cooling on the back of the module are all very important technical measures. In addition, it is particularly important to pay attention to the influence of dust and shading, the attenuation of the power conversion efficiency of components, and the contact of cable plugs.
1. The cleaning problem of the component surface
First of all, the cleaning of the module surface is a serious problem that affects the power generation of photovoltaic power plants. Although everyone has a consensus on this issue, it is often overlooked in actual operation, especially in areas with relatively little rain and relatively large sandstorms and dust. The impact of shading on the annual power generation of the power station is generally 5% to 10%, and if the roof photovoltaic is basically not cleaned throughout the year, the loss of power generation will even be as high as 10-20%.
2. Attenuation of photovoltaic modules
The attenuation of photovoltaic modules is the second serious problem that affects the power generation of photovoltaic power plants. After a photovoltaic power station runs for 3-5 years, due to the light attenuation of photovoltaic modules, shading hot spots, PID attenuation, etc., the performance of photovoltaic modules will suffer from serious attenuation, usually this attenuation is not uniform, and power generation between modules The difference in performance will gradually widen.
For example, the output power deviation of new components is usually ±3% (national standard). Due to various reasons, this deviation can reach 5% to 10% after 5 years of operation. When these components form a component string, it will lead to serious problems. The overall power generation performance will be affected by the worst module performance in the string and lose 10% of the power generation.
To solve this problem, it is necessary to regularly check the performance of the photovoltaic modules in the photovoltaic power station. After the problem is found, it is necessary to take measures such as reorganization, installation and elimination of PID circuits for different problems to solve the problem. Components with serious problems should be replaced in time. The ultimate solution to this problem is to use multi-channel MPPT inverters as much as possible. Multi-channel MPPT string inverters can help solve the problem of differences caused by uneven attenuation of each string component.
3. Ventilation and shading effects of photovoltaic modules
The ventilation and shading effects of photovoltaic modules are also one of the factors that affect the power generation of many photovoltaic power stations. Although photovoltaic modules are affected by temperature and fear of shading are determined by the characteristics of photovoltaic cells themselves, we can also try our best through the later operation and maintenance of the power station. Reduce the impact of these problems on photovoltaic power generation, strive to improve the operating environment of photovoltaic power plants, and increase the power generation capacity of power plants.
4. The cable plug contact problem
Finally, the good contact of various cables and plugs inside the power station is also the main link to ensure the normal operation and power generation of the photovoltaic power station. Regular inspections are made to ensure that each plug is in good contact, eliminate hidden troubles, and avoid failures and disasters.
Although there are many main factors affecting the power generation of photovoltaic power plants, as long as we carefully analyze and actively carry out post-operation and maintenance for specific problems, the power station can fully exert its functions and functions, increase power generation, and improve the life of power station equipment.