This is done by growing algae in plastic containers filled with sewage floating in the ocean.
The NASA algae biofuel process starts with algae being placed in sewage-filled plastic bags. These bags are called OMEGA which stands for "offshore membrane enclosures for growing algae". The OMEGA bags are semi permeable membranes that NASA developed to recycle astronauts' wastewater on long space missions. In this case, the membranes let freshwater exit but prevent saltwater from entering.
The benefits of the new biofuel method are that it does not compete with agriculture for land, freshwater, or fertiliser.
Another advantage of the NASA algae biofuel process is the fact that the method cleans wastewater during the biofuels creation process, which means it can help remediate dead zones.
Combining these benefits with algae products such as biofuel, fertiliser, and animal feed, makes this new technology cost-competitive with land-based production methods for algae biofuels.