Floating Solar Islands Could Extract CO2 From Seawater and Produce Fuel

Researchers from Switzerland and Norway have come up with a plan to build ‘Solar Methanol Islands’ that convert carbon dioxide from the atmosphere into fuel.

In order to create large-scale, workable facilities, the islands would have to be grouped together. If we were to build enough of these facilities, eventually they would completely offset the global emissions from fossil fuels and help to protect the planet from global warming.

Published in PNAS, the researchers propose using a number of highly exciting technologies in order to recycle carbon dioxide into liquid fuel with the help of the sun.

They argue that, yes, a huge reduction in carbon dioxide emissions from fossil fuels is needed, however carbon-based liquid fuels, for one reason or another, will always be used  as the go to fuel source for the foreseeable future.

“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. The recycling of atmospheric CO2 into synthetic fuels, using renewable energy, offers an energy concept with no net CO2 emission.”

The researchers say that it shouldn’t be too difficult to make these groups of islands. The technology and proof of application is already there and there is a plethora of suitable locations around the world where they could be placed.

An artist’s interpretation of what these islands might look like.

They say that the floating solar islands would resemble large-scale floating fish farms. Using photovoltaic cells, they will convert solar energy into electricity. This, in turn, powers hydrogen production and CO2 extraction from the saltwater. The methane by-product produced as a result would then be reacted to form methanol that can be reused as a fuel, “which is conveniently shipped to the end consumer,” they wrote.

Possible geographical locations for solar methanol islands. The sites satisfy the required physical conditions. – PNAS

The researchers noted certain criteria for any sites that were deemed suitable to house the project. Water depth had to be less than 600m so that the islands can be properly moored and areas where wave height was less than seven meters and had a low probability for hurricanes. They pointed to several locations around the world, with the coasts of Southeast Asia, northern Australia and the Arabian Gulf the most suitable.

In one single facility, there would be 70 of these artificial floating islands. This would cover an area of only one-kilometer square, or 0.4 square miles. The team estimates that output from 3.2 million floating islands would far exceed the total global emissions from fossil fuels.

Study Author Andreas Borgschulte told Newsweek:

“[The] biggest challenge is the development of a large scale device to extract CO2 from seawater. 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.”

They are currently working to develop prototypes of the floating islands and expect to make more progress reports in the near future.