ZHENJIANG, China: CECEP Solar Energy Technology (Zhenjiang) Co., Ltd. (hereinafter referred to as CECEP Solar Energy Zhenjiang Company) has come up with a solution for the dust on the surface of PV modules that blocks, absorbs and reflects light, thus decreasing light transmittance and impacting the power generation efficiency of the module. The impact is, according to the estimate of relevant institutions, in areas with a large quantity of sand blown by the wind, such as Spain, the loss of generated energy caused by dust can reach 25%; in California of the U.S., the annual generated energy loss caused by sand and dust is 7%; in India, the generated energy loss caused by dust is 17%-25% on average.
The highlight of PV installation in 2017 was the explosive growth of distributed PV power stations. According to the introduction of Wang Si, researcher of Energy Research Institute National Development and Reform Commission: “The accumulative installed capacity of PV power stations in 2017 is about 52GW, including installed capacity of distributed PV power stations of 20GW. “
However, such characteristics as being small scale and the scattered geological locations of distributed power stations make the operation and maintenance of power stations more difficult. General Manager of ANX Technology Wang Jun expressed that, “Many people still misunderstand the operation and maintenance of distributed PV power stations. They think distributed power stations do not need operation and maintenance, which lead to disorderly management of power stations and dust blocking problem is severe in some power stations, which severely decreases the generated energy of the module. In addition, most industrial and commercial distributed roof power stations are constructed on color roofing, with large risks for operation and maintenance, missing inspection may occur and cleaning may not be completed properly.” With this background, it is difficult to ensure periodic cleaning and maintenance for distributed power stations (especially distributed ones on color roofing). At present, dust is removed mainly by rain flushing the surface of the module. However, as the frame of the module is higher than the glass, some dust will deposit on the frame bottom after flushing, and the accumulated dust will cover the cell and lead to a local hot spot effect. This not only severely influences the output efficiency of the module but also the high temperature will also accelerate material breakdown and greatly reduce the service life of module. This will significantly impact the comprehensive income of the owner, and local overheating may even cause fire and accident.
For this phenomenon, CECEP Solar Energy Zhenjiang Company innovatively developed the drainage module, which not only effectively solves the problem of dust accumulation at the bottom of the module but also provides a self-cleaning function for the module. The so-called drainage module can effectively eliminate the influence of accumulated dust on the module, enhance generated energy of the power station and reduce the hot spot effect without influencing the performance of the module. Meanwhile, nano-modified material is used for the surface of the membrane to improve smoothness of the surface and reduce friction coefficient, making dust slip more easily; the combination of self-cleaning membrane and antistatic effect can prevent accumulation of charge; dust will slip under the effect of dead weight and wind force, keeping the surface of PV module clean.
According to the research and development personnel of CECEP Solar Energy Zhenjiang Company, “Such a drainage module is more suitable for distributed power stations on color roofing. When modules are paved on the roof, they are not cleaned for a long time. Due to small installation inclination, dust is more likely to accumulate at the bottom. In severe cases, it may even block the cells of both rows, which will severely influence the generated energy. The drainage module developed by us will effectively solve the dust accumulation problem and increase generated energy of power stations. “
In addition, application of the drainage module can greatly reduce the operation and maintenance cost of power stations. It is reported that the cleaning cost of power station is RMB 3,000-10,000/MW as the scale of distributed PV power station is small and it is difficult to remove dirt, dust, industrial dust and particles. The design plan of drainage module is more suitable for drainage and dirt removal, thus saving a lot of cleaning cost of power station.
CECEP Solar Energy Zhenjiang Company carried out investigation for the project of drainage modules in 2016 and has currently completed the internal test and verification. The Company is able to manufacture the module in batches and plans to put it on the market this year.
Source: CECEP Solar