Floating Solar Farms
Scientists have proposed floating solar farms as a way to combat the climate crisis. A research team from Norway and Switzerland published a study in the scientific journal Proceedings of the National Academy of Sciences of the United States of America (PNAS) suggesting that these floating clusters of solar panels could reduce our reliance on fossil fuels. (1, 2)
In their paper, the research team writes, “Humankind must cease CO2 emissions from fossil fuel burning if dangerous climate change is to be avoided. However, liquid carbon-based energy carriers are often without practical alternatives for vital mobility applications.” (2)
Image Source: Artist’s conception of solar islands in the open ocean. PNAS
Competing with Fossil Fuels
Andreas Borgschulte, a co-author of the study, told Newsweek that one of the big issues with renewable energy is producing enough for it to be competitive with fossil fuels on a larger scale. The study’s solution to this problem is floating islands consisting of about 70 circular solar panels. The islands would cover about one square kilometer, roughly half a square mile. (1, 3)
The electricity that the solar panels produce would split water molecules into hydrogen. That hydrogen would then react with CO2 from seawater, producing methanol. (3)
This idea arose when the Norwegian government asked researchers to figure out how to push fish farms into the open ocean. The farms would need a source of energy, and energy-producing islands were proposed. This research team took it a step further by adding energy storage to the islands. (1)
Fueling Transportation
Bruce Patterson, a co-author of the paper, is a physicist at the University of Zurich. In an interview with NBC News, he said, “We’d mostly want to use the fuel in airplanes, long-haul trucks, ships, and non-electrified railroad systems.” (3)
Patterson told NBC News that one of these floating solar farms could produce 15,000 tons of methanol a year. That would be enough to fuel a Boeing 737 on 300 roundtrips between New York and Phoenix. (3)
Methanol is cleaner-burning than fossil fuels. And the carbon dioxide that it produces would return to the ocean, where the floating solar farms could reuse it to make more methanol. (3)
“Over about a year or a year and a half, it’ll end up in equilibrium again,” Patterson said. “We’ll be able to take it out of the ocean and complete the cycle.” (3)
The solar farms would need to be placed carefully. They would do best in areas with low wave height and hurricane probability. The water depth would need to be less than 600 meters so the islands could be moored correctly. The team has found suitable locations off the coasts of South America, Australia, and Southeast Asia. (1)
An Ambitious Proposal
In order to exceed global fossil fuel emissions, the team estimates they would need 3.2 million islands. They recognize that this is ambitious. They are currently working on prototypes of the islands. (1)
“[The] biggest challenge is the development of a large scale device to extract CO2 from seawater,” Borgschulte told Newsweek. “This process is the only one of the total system [that] has not yet been fully developed. All others exist already on an industrial scale.” (1)
Peter Edwards, a Professor of Inorganic Chemistry at the U.K.’s University of Oxford, did not participate in the research but has concerns about the project’s feasibility. He has questions about how the solar panels will endure an ocean environment and if the farms will be able to produce energy at the proposed scale. Additionally, he has concerns about how maintenance will work for the floating solar farms, as they will be off-shore. (1)
