ENERGY SECURITYCan Floating Solar Islands Meet the World’s Future Energy Needs?

By Live Oftedahl

Published 6 January 2023

Covering less than ten per cent of the world’s hydropower reservoirs with floating solar panels would yield as much energy as all hydropower does today, one researcher says.

Trygve Kristiansen does research on floating solar power, which are photovoltaics supported on the water. He believes that floating solar panels could play an important global role in the transition to greener technologies. He is a professor of marine technology at NTNU.

“By covering between five and ten per cent of the world’s hydropower reservoirs with floating solar, we could produce as much electricity as all hydropower does now,” he says.

Doing this would also limit evaporation from these reservoirs.

“Less evaporation would be a good thing in areas where water is a scarce resource,” says the professor, who is also a supervisor in SFI Blues, a centre for research-driven innovation focused on developing and improving floating structures for the next generation of ocean industries.

Floating photovoltaics are now regarded as a major opportunity to provide clean electric power to major cities, especially in Asia. Solar roofs are not sufficient to fill the need.

“Many of the largest cities are located by the sea, and floating solar will be able to thrive there. In addition to large surfaces, the sea offers an important cooling effect,” says Kristiansen.

Using Ocean Space
Trygve Kristiansen thinks we don’t need to stop there. Floating solar could be used to a far greater extent than solely on hydropower reservoirs.

“If you look at the world’s anticipated overall energy needs in 2050, we could be even more ambitious. We calculated that if you put solar islands on 0.17 per cent of the world’s oceans, the power needs for the entire world would be covered,” says Kristiansen.

That 0.17 per cent of ocean space corresponds to approximately twice the land area of Norway.

“I can also envision these solar islands being charging stations for ships. They could also be used to generate electricity for floating factories that produce renewable fuels like hydrogen or methanol,” he says.

Kristiansen has co-authored an article on the topic in the journal PNAS (Proceedings of the National Academy of Sciences).

The article has received a great deal of international attention, including from CNN and the BBC.