'Floatovoltaics' Could Generate Substantial Clean Energy

Deploying floating solar panels on bodies of water is a developing clean energy technology increasing in use. The so-called “floatovoltaic” systems gather renewable energy from the sun, while at the same time shading lakes and reservoirs and reducing evaporation.

A recent study, Decarbonization Potential of Floating Solar Photovoltaics on Lakes Worldwide, found that if such systems were built on just about 6% of the lakes across the globe, and covered 10% of the water surface area, about 16% of countries’ energy demand could be met. The study, published in the journal Nature Water, noted that there are wide variations in energy potential across countries depending on their location, climate, and geography. Some countries, such as Ethiopia and Bolivia, could meet all or most of their energy needs using floatovoltaics, while countries with cooler and cloudier climates have much less potential to meet their energy needs.

Floatovoltaics are solar panel arrays mounted to a floating structure and moored to the bottom of the water body. Solar power is the fastest growing source of energy generation in the U.S. and is expected to provide 6% of total power demand this year. The study noted that water surfaces are increasingly being used for solar projects due to land-use pressures and the expense of building land-mounted solar arrays.

The study looked at the energy generation potential on 1 million water bodies worldwide. Researchers then narrowed down the suitable lakes, which had to be within 10 kilometers of a population center, not subject to icing over for more than six months, and not dried up. A total of 67,893 lakes met those constraints, while 94% were not suitable under those criteria. Researchers then calculated the total power output for each, using 10% of the surface area and taking into account climate factors. The total annual power output was calculated a 1,320 terrawatts for hour (TWh). One TWh can fully power 70,000 homes for a year.

Further research is needed on how effective floating systems would be at reducing evaporation, and what about of surface area coverage can produce the optimal amount of energy without causing ecological effects from reduced light reaching the water body, the study indicates. It also suggests that for developing countries, floatovoltaics could be a good option to meet their energy needs without building fossil fuel infrastructure.