With the growth of global population and the rapid development of economy and society, the demand for energy is also increasing day by day. Although traditional fossil energy still occupies the dominant position in the global energy structure, these energy sources will inevitably release a variety of pollutants and carbon dioxide greenhouse gases in the process of consumption, which will have a serious impact on the global ecological environment protection and the response to climate change.

Therefore, countries around the world are vigorously developing new energy technologies, such as wind power, solar energy, nuclear energy, geothermal energy Biomass energy, etc.

China has a vast territory and abundant resources, rich land resources and light and heat resources. In recent years, the proportion of new energy power generation in the national energy structure has also increased year by year.

Take solar energy as an example. Whether it is a large-scale solar power station or small solar system installed on the top of rural houses and yards in the construction of a new countryside, the situation is becoming more and more common in all parts of China. While meeting a certain amount of national energy demand, it also promotes the improvement of the Environmental Outlook of the vast region.

However, solar power station is affected by the physical principle of energy conversion and must be based on receiving solar radiation in a large area. Therefore, when the light energy conversion efficiency of existing solar panels is difficult to achieve a significant breakthrough in the short term, on the one hand, flat terrain conditions are required;

On the other hand, we need to expand the coverage area of solar panels as much as possible. In this context, we will naturally look at the desert area, because there are almost no human activities and arable land, and the area is vast, the topographic relief is small, and the light and heat resources are abundant, which has excellent conditions for solar energy development.

In recent years, China has developed and built a large number of large-scale solar power stations in Xinjiang, Qinghai, Inner Mongolia and other provinces (regions). In addition, China is actively planning to build corresponding photovoltaic bases in Western Jilin, Qinghai Tibet Plateau, Sichuan Basin and other regions.

Many of these solar power stations are located in deserts, Gobi or relatively arid areas. Some people can’t help but ask when building solar power stations in arid deserts and surrounding areas, where the wind and sand are generally relatively large, it is easy to fall dust on solar panels. If these dust are not cleared in time, it is bound to seriously reduce the power generation efficiency of solar panels. How do we do it?

At present, the solar power stations or small-scale household solar panels will be affected by dust. Whether in desert or plain, if the dust on the solar panels is not cleaned, the power generation efficiency will be reduced by 30% in a month on average. Based on the global installed solar capacity of 500gw in 2020, the annual economic loss caused by dust reducing power generation efficiency is as high as US dollars 5 billion. By 2030, the installed capacity of global solar power generation will increase to 1400gw, and the loss value will be as high as 13 billion US dollars.

For a long time, in order to solve this problem, the commonly used method is basically to use water washing, the high-level method is to use pressurized water jet and spray, and the low-level method is to use manual scrubbing. Both low-level and high-level methods require the application of a large amount of water.

According to the current scale of global solar power stations, the pure water used for cleaning solar panels alone each year is as high as more than 37 billion liters, equivalent to the annual water consumption of 2 million people. Of course, the above traditional method is also quite difficult and costly. The labor cost of manual washing, the power consumption of mechanical washing and equipment maintenance costs need to be calculated into the comprehensive cost of the power plant.

Moreover, no matter what kind of washing method is used, it is impossible to keep the cleaning effect of solar panels the same. There will certainly be some blind areas and dead corners, and some solar panels are not washed clean enough.

In this way, it is inevitable to produce a “hot spot effect”, that is, the parts that have not been cleaned, and the solar panels will be very likely to change from power generation units to power consumption units, which will reduce the overall power generation efficiency on the one hand, On the other hand, it will also cause heat, accelerate the aging of solar panels, and even cause fire.

At the same time, many US dollars are built in arid areas or even desert areas, where water resources are very few, and the application of water washing method itself is a waste of resources. Therefore, the research on new cleaning methods for cleaning solar panels has become an important field in many countries.

The effect of one solution has been well verified, that is, by adding a special and very thin coating on the solar panel, it can protect and isolate dust well without affecting the sunlight.

The specific principle is to use electrostatic repulsion. Apply a current or an appropriate voltage range through the electrode (such as a metal rod), so that the electrode passes right above the surface of the solar panel, and the dust particles attached to the panel are charged (the silicon dioxide particles in the dust will attract a small amount of moisture in the air, so that the dust particles can be charged). Then, the opposite charge is applied to the thin coating film, so that the glass surface of the solar panel can strongly repel the dust particles.

The electrode energy source of dust “repulsion” implemented in this way mainly depends on the electricity generated by a small amount of solar panels, and its power consumption is far less than that lost due to dust coverage.

When this kind of coating is used, it can effectively make dust, yellow sand, soot and even bird droppings difficult to be firmly adsorbed on the solar panel, so that these covers will be effectively removed when it rains, which is equivalent to a self-cleaning function. If there is little rainfall in the area where the solar power station is located, it is OK to carry out manual or mechanical auxiliary cleaning regularly, which is much lower than the previous water consumption and washing frequency, and undoubtedly greatly reduces the operating cost.