Scientists say they have successfully converted discarded plastic into hydrogen fuel, which in turn could be used to run cars.
Light-absorbing material is added to the plastic before it is placed in an alkaline solution and then exposed to sunlight, which creates hydrogen, said researchers from Swansea University in the UK.
The process could be cheaper than recycling because any kind of plastic can be used and it does not need to be cleaned first, they said.
"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," said Moritz Kuehnel from Swansea University.
Most plastic bottles are made from PET (polyethylene terephthalate) which can be recycled but often end up being burned or thrown into a landfill.
"But even if you do recycle it, it needs to be very pure - so only PET, nothing else mixed in with it... and it has to be clean, no grease, no oil," said Kuehnel.
"Potentially you need to wash it which is very expensive, and even if you do all of that, the plastic you get is not always as nice as virgin material," said Kuehnel.
"The beauty of this process is that it is not very picky. It can degrade all sorts of waste," he said.
"The process produces hydrogen gas. You can see bubbles coming off the surface. You can use it, for example, to fuel a hydrogen car," Kuehnel said.
However, he warned that rolling out the project on an industrial level may still be years away.