It’s one known obstacle in the rise of renewable energy: a lack of space. In many places, extensive solar fields and wind farms compete with nature, housing and industry scarce land.
But there is still plenty of room at sea for the construction of solar and wind energy, according to a report study published on Friday in Science Advances. The researchers mapped all suitable places in the world and calculated the possible yield per location. This shows that only 1 percent of the suitable sea surface would be needed to meet 30 percent of future electricity needs.
The researchers used established criteria to determine which places at sea are suitable. Such an area is not protected, is less than two hundred meters from inhabited areas, the water is no deeper than three hundred meters and is covered with ice for a maximum of half the year. Of course, there must also be sufficient sunlight or wind to generate energy.
Relatively small shares
According to the conditions, approximately 3 percent of the global sea surface is eligible for wind turbines, and 1.3 percent is suitable for solar panels at sea. These are relatively small shares, but together they add up to approximately fifteen million square kilometers of sea.
The results can help governments determine their offshore strategy, the authors write. “For example, the south of South America is more suitable for the development of offshore wind energy, while tropical countries such as Indonesia should give priority to offshore solar energy.”
Two maps in the report published on Friday show the expected annual electricity yield per location from wind energy (A) and solar energy (B).
Wen et al., Sci. Adv. 11, eadx5580
Sara Golroodbari, assistant professor of solar energy at Utrecht University, is not surprised that the sea offers sufficient space for generating solar and wind energy. She was not involved in the investigation published on Friday.
“We have previously looked at the wind projects already planned in the North Sea,” says Golroodbari. “If you were to add solar panels, it would provide more than enough electricity to meet the total needs of the Netherlands.”
More sunlight
Besides space, the sea offers even more advantages. The wind reaches significantly higher speeds than on land, allowing wind turbines to generate more energy. “There is also generally more sunlight at sea,” says Golroodbari. “The floating solar panels benefit from this.”
The cool seawater also ensures that solar panels do not get too hot, making them work more efficiently. Five years ago, a study van Golroodbari that solar panels on the North Sea generate almost 13 percent more energy than the same panels on land.
At the same time, there are still plenty of challenges, Golroodbari acknowledges. “Solar panels at sea must be able to withstand a storm like the one that passed over the North Sea last night. As a result, they cannot always be positioned at the optimal angle.” Nevertheless, an initial pilot was successful: it has been floating since last year Mergansernamed after a type of sea duck, off the Dutch coast.
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