BACKGROUND

Background: Floating PV and reservoirs

• Floating solar PV is among the fastest growing technologies in the renewable energy sector. While the very largest schemes are in the pioneering FPV countries, such as China, India, and Korea, projects are taking off throughout the world, particularly in Europe, Latin America, Africa, and the Middle East.

• The multiple benefits of combining the energy potential of the sun and water, saving vast areas of land in densely populated areas, and reducing evaporation from reservoirs in water-scarce countries, are combining to entice numerous countries to embark on research, launch prototypes, and then progress to commercial-scale systems.

• The largest manufacturer of PV systems recently reported having completed 280 floating solar projects in more than 30 countries, and having new projects totalling 1.5 GW in the pipeline. A speaker at our AFRICA 2023 conference in July commented that hydro schemes today should be designed from the outset to incorporate other renewables such as floating FPV.

• Dam-mounted solar panels are another important way of creating synergy between hydro reservoirs and solar power. A good example is Muttsee in Switzerland, where 5000 solar panels mounted on the dam produce around 3.3 GWh/year.

Background: Hybridization of water reservoirs and intermittent renewables

• Beyond land surface pooling, combining the energy potential of the sun or the wind and water brings additional benefits, delivering dependable and dispatchable renewable electricity, reducing interconnection costs, and optimizing the use of water.

• The potential is immense. Researchers at the US National Renewable Energy Laboratory have estimated that adding floating solar panels to reservoirs that are already home to hydropower stations could provide as much as 7.6 TW of additional electricity. This figure, which represents an estimate of the technical potential, is probably optimistic. However, it illustrates the importance of the subject: in 2022 the world’s total installed capacity was 8.5 TW.

• Solar and wind powerplants can be hybridized with all kinds of reservoirs, such as those for hydropower and irrigation. There are various configurations of combinations, and some of them do not ‘consume’ any water in the process. Hybridized powerplants can be connected to the grid, or deliver electricity off-grid, or produce green hydrogen. They are suitable for all climates, including arid or semi-arid climates, where they also have the advantage of saving water.