Double-Glazed Modules, Reliable for “Complementation between Fishery and PV”
2019-11-19


Huzhou, situated in the north of Zhejiang Province and facing Wuxi and Suzhou across the lake, has long been reputed as Land of Fish and Rice, Land of Silk and State of Cultural Heritage, and the pearl of South Taihu Lake. Now as a pilot field for “Complementation between Fishery and PV”, Huzhou is also famous in the PV industry.

Driving southward from Beijing, when the reporter felt hot and humid wind blowing in the face, after several hours of tiring journey, we suddenly realized that we were almost there—Huzhou where the project of 5MW “Complementation between Fishery and PV” is located. Looking at the PV power station from afar and the fish pond covering over 1,000 mu from near, “All over this winding stretch of lake, what meets the eye is a silken field of large dark blue leaves (double-glazed modules), transparent and crystal clear, and reaching rather high above the surface, like the skirts of dancing girls in all their grace. Dark blue leaves are linked by solid pillars,” Moonlight over the Lotus Pond by Zhu Ziqing, delivers another feel while being quoted for the “Complementation between Fishery and PV”.

Gazing into the distance, there are tens of thousands of PV panels on the surface of hundreds of mu of fish pond. How spectacular!


双玻组件,“渔光互补”的可靠性担当

 

In recent years, due to the scarcity of land resources and the restrictions of land properties, it is more difficult to locate PV power stations. PV power stations tend to be established near mountains, beaches, ponds and other harsh environments. “Complementation between Fishery and PV” refers to the combination of fishery and PV power generation, by means of setting up a PV panel array above the water surface of fish pond. Fish and shrimp farming can be carried out in the water area below the PV panel. PV array shelters well for fish farming, thus forming a new power generation mode of “power generation from the top and fish farming at the bottom”.

Despite advantages of the “Complementation between Fishery and PV”, the water surface power station is confronted with great challenges. It is understood that the water surface power station is characterized by high humidity and strong UV reflection radiation, which is a severe test for the modules. High humidity and frequent fluctuation of water surface make the PID of PV modules obvious, the aging of packaging materials accelerated, and the problem of hidden crack very serious, which poses higher requirements for PV modules, such as PID resistance, crack resistance, UV aging resistance, salt spray resistance and high waterproof level.

The double-glazed modules are used in the project of 5MW “Complementation between Fishery and PV” in Huzhou, Zhejiang Province visited by the reporter this time. The investor introduced that it is rainy and sometimes there will be acid rain here. Since the water vapor transmission through the back panel is about 2-3g/day and water vapor invades slowly from the back panel in such environment with a lot of water vapor, the long-term performance of the modules are questionable, while the case would be contrary for the double-glazed modules with zero water permeability.

The reporter learned that the water surface PV project in which single-glazed modules were applied would suffer from erosion of high temperature and rainwater in summer, seriously affecting the income of PV power station. Considering these problems, they have chosen the double-glazed modules with high weather resistance, PID resistance, crack resistance and higher power generation. The owners chose double-glazed modules out of high recognition of double-glazed modules. Some owners engaged in the single-glazed surface PV projects have also shown to the reporter pictures about the failure of modules applied in the water surface power station. The problem mainly lied in the fact that the water vapor entered to cause bubbles, and after the hidden cracks, the water vapor entered to form snail trails, which were rather troublesome. To their relief, there are currently double-glazed modules in the market, and thus the annoying problem has finally been solved.


双玻组件,“渔光互补”的可靠性担当

 

  

of the project of “Complementation between Fishery and PV” in Huzhou, the water permeability of the glass in double-glazed modules used in the power station is almost zero, so it is not necessary to consider the water vapor entering the modules to induce the hydrolysis of EVA film, which makes the PV power station fearless of the invasion by high humidity near the water surface and the disturbance by rainy environment.

In hot and humid areas, the heat dissipation performance also affects the power generation of PV modules. As for the water surface power station, due to much water vapor in the modules, the evaporation of water vapor will take away the temperature at the back of the modules, which has a good effect on cooling of the modules. Therefore, we tested the temperature at the backs of the double-glazed modules and single-glazed modules respectively, finding that the temperature at the back of the double-glazed modules is about 2°C lower than that of the single-glazed ones. According to the power coefficient characteristics of the modules, the output power of double-glazed modules in this environment will be higher than that of the single-glazed ones. “Favorable heat dissipation and guaranteed power generation.” the on-site technical engineer gave a brief and comprehensive introduction to the reporter.

According to the on-site staff for the project of “Complementation between Fishery and PV” in Huzhou, during the 13 months from the end of May 2016, the power station has generated 7,989,696kwh in total. Seen from analysis on the data extracted from the site, it generates about 4% more electricity than the nearby project of “Complementation between Fishery and PV” in which single-glazed modules are applied.

An industry expert said that the biggest advantage of “Complementation between Fishery and PV” lies in “dual-use of one land and complementation between fishery and PV”, which does not need to occupy valuable agricultural, industrial and residential land, and yields win-win outcomes in terms of social, economic and environmental benefits. How to ensure the sound development of fishery ecology to the greatest extent, so that all kinds of fish have living space? According to the expert, the double-glazed modules are widely used in the project of “Complementation between Fishery and PV”, because the double-glazed modules can be well combined with the fishery needs. The double-glazed modules can be divided into transparent ones and non-transparent ones. This excellent combination design of transparent double-glazed products can be used to breed light-loving aquatic products under the pond, while the non-transparent double-glazed products can meet the needs of some fishery products that have no special requirements for light.

In addition, unlike the construction of PV power stations in mountainous areas and on land, most of the roads are muddy on the construction site of the project of “Complementation between Fishery and PV”. Every step is mired in mud, which makes it very difficult to move forward. The project of “Complementation between Fishery and PV” is more difficult and complex in construction. It is understood that this project adopts porcelain-white double-glazed modules, and adopts the installation method of gluing with sealing performance, which is especially suitable for the project of “Complementation between Fishery and PV”, and greatly lowers the installation difficulty and workload of workers. The unique edge banding technology of double-glazed modules significantly reduces the collision and breakage rate during the installation and disassembly of modules, and ensures the safety of modules under complex construction conditions, which is also the main reason for choosing double-glazed modules in the project. As for the floating power stations, the stormy waves, water flow and system maintenance will cause the shaking of the floating block. The stress is transmitted to the modules through the bracket, posing higher requirements for the bending resistance and crack resistance of the modules. The double-glazed modules have better crack resistance without snail trails, being more suitable for the floating power stations.

When it comes to double-glazed modules, many owners for the project of “Complementation between Fishery and PV” would unanimously praise it. In their eyes, the double-glazed modules are not only capable but also good-looking. They are generous in their praise for the double-glazed modules used in the pond, “GorgeousFantastic!” The application of double-glazed modules in the project of “Complementation between Fishery and PV” greatly increases the viewing effect. Aluminum frames does not look nice on the single-glazed modules. Besides, in the pond, the module frames are likely to cause mud gathering, and there will be mud staying in the single-glazed frames all the time, which is extremely unsightly.

The “Complementation between Fishery and PV” which just emerged is now developing overwhelmingly in Zhejiang Province. It is double-glazed modules that can undertake the task about healthy and sustainable development of “Complementation between Fishery and PV”, owing to their high reliability and other significant advantages.