Floating photovoltaic plants do not compete with other land uses. They reduce the evaporation of water and are kept cool by the water just like solar panels covering irrigation canals.

The cooling effect provided by the water increases power production from 5 to 15 per cent. Besides this, it is easy to rotate floating solar panel installations both horizontally and vertically, which provides a further energy gain, amounting from 15 to 25 per cent.

According to a recent study by Bernhard Lehner and Catherine Reidy Liermann there are altogether 17 million dam-made reservoirs larger than 100 square meters in the world. The combined acreage of all these reservoirs is more than 30 million hectares. There are also 450 million hectares of natural lakes in the world, but many of them are too large for solar power plants or exist in uninhabited northern latitudes.

India and China have been pioneers in the field. China currently has the largest installed capacity, but India has been able to reduce the cost of floating solar power plants to roughly 0.5 euros per watt, which is already eminently affordable.

India’s first floating solar power plant was installed by Nath Bose Institute for Rural Technology in Kolkata in 2014, through a pilot project supported by the Ministry of New and Renewable Energy.

In the beginning of 2024 India's largest floating solar power plants had a nominal power-generation capacity of 145 megawatts and many more were in the pipeline. For instance, in the Omkareshwar Dam there is already one 100 megawatt floating solar power plant in Khandwa district, while three others are under construction: the 100-megawatt Kelwa Khula, the 88-megawatt Indawadi and the 90-megawatt Ekhand.

Indonesia has recently emerged as the world's third superpower in floating solar electricity generation. Indonesia's largest floating solar power plant, Cirata, has a power-producing capacity of 145 megawatts, and it is planning to construct floating photovoltaic plants to 200 other reservoirs.

Current research is directed towards developing low carbon alternatives to conventional structures for floating solar power plants. In the future, floating solar power plants could produce dozens of terawatts of electricity, while saving enormous amounts of freshwater. However, it might be safer to avoid building them on large lakes or reservoirs. The Khandwa district floating solar power plant in India was hit in April 2024 by a summer storm, which caused some damage for its structures.

Even relatively small waves can cause serious damage for a floating solar power plant, but the problem can be mitigated by designing the floating installations so that they prevent the wind from touching the surface of the water. Even strong winds cannot generate waves without long stretches of open water.

*Illustrative Image.