Researchers in Edinburgh are carrying out tests to see if urine can be a potentially cheap and green energy source.
Shanwen Tao and research partner Rong Lan from the Heriot-Watt University are developing a prototype fuel cell to produce electricity from human and animal urine.
Conventional fuel cells, such as those use in cars, oxidise a source fuel such as hydrogen or methanol to produce energy.
The new study is looking at urea or carbamide, a major component of urine, as a safer alternative to inflammable hydrogen and toxic methanol.
The researchers, who have been granted £130,000 to develop their Carbamide Power System, are hoping it will offer a low-cost, environment-friendly source of energy.
They see a future for the fuel cells in submarines, the military and power generation in remote areas such as deserts and islands. It could also be used to reprocess waste water, with electricity as a by-product.
Heavy goods vehicles have already been using urea solution to cut down harmful emissions.
© Press Association 2010