The world's first "Floating on Water" power generation is 200 million KWH a year.
With its continued investment in photovoltaic power generation, China has consolidated its position as the world's No.1 photovoltaic power producer. China is not only the world's largest producer of solar panels, but also a world leader in new photovoltaic capacity and electricity generation. We also often see all kinds of fancy photovoltaic power stations on the news: "Datong Panda" power photovoltaic power station, and Singapore's land area about the size of Qinghai Tara Beach photovoltaic power station, the first results of above complementary technology above the complementary photovoltaic power station and the world's largest photovoltaic panels graphics. In recent years, China has continuously updated its performance in the field of photovoltaic power plants, and it seems that only Chinese PV can surpass Chinese PV.
What is floating PV?
A Floating PV power station is a photovoltaic system that generates electricity by floating PV modules on the water using a kind of floating base. Generally speaking, floating photovoltaic can be applied to the water surface, such as ponds, small lakes, reservoirs, reservoirs and so on. There is also a small amount of floating PV in Singapore, but the environment is not suitable for such floating PV systems
due to high wind and waves.
The first floating PV idea emerged in the early 2000s. Cielet Terre, a floating PV specialist based in Lille, France, began promoting the idea in 2006. In 2007, a small 175KW commercial power plant opened in a pond in Far Niente, a Napa Valle wine producer, to reduce energy costs and avoid taking up land. Planting vines on land can bring in higher profits. The first formal floating PV system was built in 2007 in Aichi prefecture, Japan. Subsequently, many small power stations under the megawatt scale appeared in many countries, especially France, Italy, South Korea, Spain and the United States. They are mainly for research and demonstration purposes. Due to immature photovoltaic technology at the time, the first 20 floating PV stations from 2008 to 2014 had an installed capacity of only a dozen KW, with a cumulative installed capacity of only 10MW.
There are two common floating photovoltaic power stations: one is the piling type. That is, pile down under the water and set up the bracket of photovoltaic modules on the pile, but this way is more suitable for a shallow environment. It is generally suitable for small ponds below 3 meters. This way is more difficult in foundation construction, and the cost is also increased to a certain extent. The other is the floating type. It will be connected to the photovoltaic module through the base, buoy, cable, anchor block and other devices. This way can save the foundation of construction. It can adapt to the water level up and down, and does not occupy land resources.
In 2018, floating PV attracted widespread attention. According to the World Bank, the global accumulated installed capacity has reached 1.3GW by 2018, a 100-fold increase.
What are the advantages of floating PV?
1. Land saving and it is easy to build. The ground PV is mostly built in flat terrain areas. For countries with scarce land or mountainous areas, the installation of ground PV will occupy a lot of land resources. It is difficult to build PV in some mountainous areas, which will increase the cost of photovoltaic installation. This is one of the reasons why Japan and Singapore are developing floating PV systems in recent years. In northwest China, although the land price is cheap, the transmission of electricity needs a lot of cost because of the distance from the power area. In the transmission process, the power will also have a certain loss. Therefore, it is also suitable for the development of floating PV in some reservoirs and lakes in China.
2. Reduce evaporation. In some dry and windy areas, hot weather and wind can cause water evaporation and loss of large amounts of water. In Chile, the researchers conducted experiments in two similar ponds. One is with photovoltaic floating elements and the other is an uncovered one. After 8 months of testing, the results showed that compared with the uncovered pond, the water evaporation of the pond with the floating cover decreased by more than 90%. In addition, photovoltaic cells placed on the floating cover can generate up to 68 Wp/m 2.
3. Improve the power generation efficiency of components. Improving power generation efficiency is one of the important advantages of floating PV. The increase of PV module temperature is the main factor to improve energy consumption. Therefore, the evaporative cooling effect of water can reduce the working temperature of PV in the water environment so as to improve the working efficiency of modules. Studies at the FPV test-bed in Singapore have shown that ambient air temperatures on water are about 1°C to 3°C cooler than the adjacent land environment. It reduces operating temperatures of photovoltaic modules by 5°C to 10°C. The higher wind speeds in the open water also reduce the operating temperature of the element. In addition, there is less dust on the water surface, which reduces the accumulation of dust and sand on the panel. It will affect the power generation efficiency of the element.
4. Inhibit algal reproduction in water. Intense light in ponds, lakes and other environments can stimulate algae blooms in the water. These algae will have serious consequences for lake ecology. In 2007, a large area of blue-green algae erupted in Taihu Lake in China, seriously affecting the water supply of local residents. Floating PV, which can suppress algae growth and improve water quality by covering the water surface. It also can reduce the cost of treating water quality in reservoirs.
Does floating PV have an impact on the environment?
There are many advantages of floating PV, but some people may ask, “Does floating PV have no disadvantages? What will happen to the water quality and environment if photovoltaic plants are in the water?”
Floating photovoltaics have no adverse effects on the surrounding environment, according to preliminary studies conducted by German renewable energy company BayWar on 18 May, 2021. The study began in February 2020 with BayWare collaborating with Hanze University and Buro Bakker/ATKB on the "Bomhofsplas" floating solar farm in Zwolle, the Netherlands, the largest floating photovoltaic power station outside Asia.
Floating PV plants have no ecological impact, but there are several challenges to overcome as follows.
(1). Floating equipment requirements and cost are high. The support components floating equipment need not only excellent corrosion resistance, but also low density, frost heave resistance and wind and wave resistance. In addition, the reliability of components in a humid environment for a long time, the bearing capacity and service life of the floating platform also need to be considered strictly. Therefore, the high cost of floatation equipment also increases the cost of the project.
2. High site selection requirements. The floating PV is not applicable to all waters. It must meet some requirements like a wide area, stable runoff, low wind speed, good lighting conditions, stable water level change, good development conditions and no large-scale shipping. The ecological environment is not a sensitive area of the waters.
3. Many uncertain factors. The water surface is vulnerable to wind, water level, icing and other factors. It is necessary to monitor whether photovoltaic modules have adverse effects on water quality, fish, plants and so on.
4. Maintenance difficulties. It is difficult to overhaul floating PV, especially the part of underwater anchor block and cable. The maintenance needs diving equipment. The components on the water also need to design special channels and floating pv mountings for maintenance at the beginning of construction, which increases the difficulty of maintenance.
In the context of increasingly serious energy security and climate change issues, renewable energy has attracted more and more attention from countries around the world. The emergence of various fancy solar photovoltaic power generation systems is also the result of continuous technological innovation based on local conditions. Floating photovoltaic power stations have not been developed for a long time, but they have achieved good results in a short time. In the future, the floating PV market will become a blue sea driven by technological breakthroughs and innovations without affecting ecology.