Solar On Water - A Win Win Use Case
There is always a growing demand for energy and power-hungry nations have few viable and sustainable options other than solar energy.
Rooftop solar and ground-mounted solar are the most popular solar systems, gaining rapid traction worldwide. However, scarcity and high cost of land has led to energy conscious countries looking towards water bodies for increasing their solar capacity. With nearly 70% of the earth’s surface covered with water, it makes sense to use water bodies for clean power generation. Floating Solar Panels, as the name suggests, float on water instead of being fixed on land. Solar panels are mounted on floating platforms and are modular in nature. These can be a one large structure or modules floating independently while maintaining a geometrical configuration.
Water based solar power or floating solar power plant offers an attractive option to free up extra space on land which can be put to alternative use in countries which have densely populated cities and limited agricultural land. The technology in general is also supportive of the ecology as it reduces evaporation and checks on algae growth.
Structure of a Floating Solar System:
A typical floating solar system consists of-
- A floating system comprising of a pontoon and floats made of HDPE (high density poly-ethylene) that imparts strength, UV and corrosion resistance to the system
- A mooring system that anchors the structure on the water to the bottom
- Solar panels and
These floating structures can be designed to withstand salt mist corrosion, waves up to a height of 2 metres and winds up to 190km/h. Care must be taken while installing solar panels over water bodies as warranty on these panels are voided if not handled or installed properly.
Floating Solar Panels is gaining traction in India and many other countries like Australia, the US, UK, China, Holland and Japan. Some of the large floating solar projects are –
- Jamestown – South Australia
- Yamakura Dam – Japan
- Walton-on-Thames’ Queen Elizabeth II reservoir – UK
- Balbina hydroelectric plant – Brazil
- Banasura Sagar reservoir in Wayanad, (Kerala) India
India recently saw the completion of its largest floating solar power plant in Kerala, with 1,938 solar panels installed on 18 ferro cement floaters.
Advantages of Floating Solar Panels:
One of the biggest advantages of a floating solar system over a traditional land based system is that the water bodies provide thermal insulation to solar cells which in turn increases the overall solar panel efficiency. In general, an average solar panel can convert between 16-20% of solar energy into electricity. According to a study conducted by Korea Water Resources Corporation, floating PV systems can outperform land based solar systems by 11%.
Another major advantage of floating solar panel technology is that it does not use up land which is highly precious in certain geographies. In countries like Singapore and Holland, land comes at a high premium making floating solar systems very attractive. Floating Solar Panels also free up land in populated cities. They can be built on industrial water bodies like wastewater treatment plants, cooling facilities in factories and power plants etc.
The other benefits of using floating solar plants are that they are eco-friendly, reduce water evaporation from water bodies and also minimize the risk of solar cell performance atrophy. Evaporation of water naturally cools down the panels which in turn improves the overall efficiency of the system. These lower the cleaning costs as well. It is also possible to move the floating PV structure from one place to another.
China is aggressively supporting the floating solar panel technology. Leading Chinese solar inverter maker Sungrow is planning to build the world’s large floating power plant with a capacity of 150 MW on top of a water body. The company plans to leverage the success of this project by exporting this system to other countries.
Disadvantages of Floating Solar Panels:
While there are many advantages to floating solar power plans, there are some disadvantages as well. Building these plants is more costly than building land based plants. The higher capex costs are due to increased equipment costs as well as the requirement of specialized installation. The maintenance costs are also high in general. The development of transmission infrastructure in the form of underwater cables also leads to cost escalation. As floating solar panel technology gathers momentum, customized solar panels specially designed to for water surroundings should start getting manufactured. Solar panels which are resistant to salt and mist corrosion and are light weight will find a good market from the floating solar power plant sector.
Applications of Floating Solar Panels:
Floating Solar is a new and growing market and offers a good growth opportunity for water utility companies that are large power consumers and own huge water reservoirs.
Reservoirs like dams, lakes or rivers can be effectively used for construction of these plants.
Floating Solar technology can support a Floating Farming system which will be expandable and food crops can be grown atop the water body. Similarly, many such establishments could be powered by solar energy over the water bodies.
Floating Solar Plant is a concept whose time has come and if provided proper government support and incentive can help countries achieve their clean energy targets and reduce their carbon footprint. According to estimates, if only 10-15% of Indian water bodies are utilised for setting up solar power projects, 300 GW of solar capacity could be developed which is three times the 2022 solar installation target for India.
Policy makers and government bodies should consider floating solar as an effective tool to fight climate change. Improved efficiency, higher energy density and saving on real estate costs are its biggest advantages. Floating photovoltaic is therefore, a win-win case use case both for saving water (water conservation) as well as generating low-carbon clean energy.