Scientists at the University of Swansea are hoping that they have found a solution to the waste, which kills thousands of sea creatures each year.
The research's leader Dr. Moritz Kuehnel told the BBC: "There's a lot of plastic used every year - billions of tonnes - and only a fraction of it is being recycled. We are trying to find a use for what is not being recycled."
The plan would be to cut the plastic, and add a photo catalyst to it, which would be able to absorb sunlight and turn it into chemical energy.
Testing it, researchers put the plastic into an alkaline solution before shining sunlight - or a solar simulation lamp - onto it, which produced bubbles of hydrogen gas on the surface.
One advantage it would have over recycling plastic bottles is the university's system wouldn't need plastic to be cleaned.
Dr. Kuehnel added: "Even if there is food or a bit of grease from a margarine tub, it doesn't stop the reaction, it makes it better."
It will also be cheaper than recycling, although it could be a few years before the project will hit industrial level.
However, researchers have already received funding from both an Austrian petrochemical company, and Swindon's Engineering and Physical Sciences Research Council.