Advantages of floating PV systems:
1. Rational utilization of land resources: lakes, water areas in mining subsidence areas and abandoned deep mines can be used to improve the comprehensive utilization rate of land.
2. Increase the power generation: the water surface has the functions of cooling and mirror reflection on the photovoltaic modules, and the power generation of floating solar systems
is significantly higher than that of the ground PV systems.
3. Environmental protection: covering the solar panels on the water can reduce the evaporation of the water surface and inhibit the reproduction of algae in the water, which is conducive to the protection of water resources.
4. Little dust. Easy to clean. It can avoid the weed shadow shade.
Disadvantages of floating PV systems:
1. Relatively huge difficulty in construction, operation and maintenance.
2. The equipment has high requirements for anti-corrosion and waterproof and PID resistance.
3. High cost of comprehensive development of the floating PV project.
4. Uncertainty exists in the way of declaration scale and land use policy.
Forms of water photovoltaic:
1. Piling type (water depth ≤3m)
2. Floating type (water depth >3m)
1) Floating piles
2) Independent buoys
3) Standard buoys
4) Float tanks + steel walkway plates
Comparison of different forms (actual case data)
1. Basic information about this project
The project was located in an artificial lake with a water area of about 330 mu, a water depth of about 5m and a water level difference of 0.5m. The module inclination angle is 23°, and the installed capacity is 8.5MW. It was connected to the grid in December 2015. It adopted the standard buoy, custom buoy, custom buoyancy box and a variety of floating body forms. Place on the shore of the booster, and combine the underwater cable and bridge with a high voltage line.
2. Cost comparison
The cost of pile foundation is related to pile height, and the cost increases by about 0.15 yuan /W for each 1m increase in water depth.
3. Development trend
The existing water surface photovoltaic scale is small. The "fixed piling + fixed scaffolding" was mainly used in the shallow water area (within about 3m). The "fixed piling + tracking scaffolding" was used only in a small number of shallow water areas.
The deep-water floating type (about 3-10 meters) is still in the demonstration stage, and the technology maturity needs to be improved. It is an important development direction of the future water surface photovoltaic.
The limits of deep water zones will be broken and the number of floating applications will be increased in the future.