Can a floating solar island meet the world’s future energy needs?

Trygve Kristiansen works on floating solar energy, which are photovoltaics powered on water. He believes that floating solar panels can play an important role globally in the transition to greener technologies. He is a professor of marine technology at NTNU.

“By covering 5 to 10 percent of the world’s hydroelectric reservoirs with floating solar, we can produce as much electricity as all hydroelectricity today,” he said.

Doing this will also limit evaporation from these reservoirs.

“Less evaporation would be a good thing in water-scarce areas,” said professor and supervisor of SFI Blues, a research-based innovation center focused on developing and improving Floating structure for the next generation of ocean career.

Floating photovoltaic is currently seen as a great opportunity to provide clean electric power to major cities, especially in Asia. The solar roof is not enough to meet the demand.

“Many things of biggest city located near the sea and floating solar will be able to thrive there. In addition to its vast surface, the sea provides an important cooling effect,” says Kristiansen.

Use ocean space

Trygve Kristiansen thinks we don’t need to stop there. Floating solar energy can be used to a much greater extent than just used on hydroelectric reservoirs.

“If you look at the world’s projected overall energy demand in 2050, we could be even more ambitious. We’ve calculated that if you put solar islands above 0.17,” he said. % of the world’s ocean area, the energy needs of the whole world will be met,” he said. Kristiansen.

0.17% of that ocean space corresponds to about twice the land area of ​​Norway.

“I can also envision these solar islands as charging stations for ships. They can also be used to generate electricity for floating plants that produce renewable fuels like hydrogen or methanol,” he said. speak.

Kristiansen co-author one article about the topic in the magazine PNAS (Proceedings of the National Academy of Sciences) in 2019.

Floating solar works best when weather conditions are calmer

“The ocean is vast,” says Kristiansen.

However, not all oceans are suitable for the development of floating solar.

“Place floating solar battery in areas with the mildest weather conditions, wind and waves can be clearly an advantage. The Doldrums, a belt around the Earth near the equator, have little wind and the sun shines directly down, so these are well positioned for floating solar. The same goes for places where there are waves instead of rough seas, says Kristiansen.

Floating solar competes with offshore wind power

“If you cover a square kilometer with solar panels in southern Spain, where the average annual solar radiation is 200 watts per square meter, then floating solar will be able to generate about 44 megawatts. Wind turbines today produce about 6 megawatts on average for the same area,” he said.

How does solar photovoltaic float?

We have yet to find the best technology for this approach. Floating solar must be cost effective. At the same time, solar islands need to be able to withstand some rough seas and strong winds. Floating structures must follow the waves for it to work.

So how can solar panels float on water? And what is the best solution to link them?

Kristiansen highlights two key concepts for floating solar.

• One option includes floating membranes attached to floating washers. The Norwegian company OceanSun has built a number of full-scale membrane support systems.
• The second concept consists of smaller, rigid modules interconnected in large matrices. Several companies offer different variants of the system, including Equinor and Moss Maritime, which are testing a floating prototype off the island of Frøya.

“Other concepts are also possible, like air cushion support structures and flexible hoses connected in different configurations,” says Kristiansen.

Floating solar power is a fairly new concept

Several floating solar pilot plants have been built around the world. They are commonly found on island waters, in cities, and in communities without other energy sources. Floating solar panels have been installed on several hydroelectric reservoirs in Japan and China.

“We also need this power in Norway, for example on site at aquaculture facilities or to power new Norwegian industrial sites. power-intensive industries, such as battery factories,” he said.

Expansion ideas Solar power panels in floating structures on dams and other water sources on land and in the ocean is relatively new.

“Floating solar is an area of ​​research at a very early stage. Only in the last two years has it started to attract attention. The EU has announced calls for research projects in the past year,” he said. Kristiansen said.