Human waste to provide 'pee power'

Researchers at the University of Bath have made significant steps in developing a miniature fuel cell that will generate electricity from the most unlikely of all potential power sources — human waste.

The team, from the University’s Department of Chemical Engineering, Department of Chemistry and Centre for Sustainable Chemical Technologies, say that the development is an affordable, renewable and carbon-neutral way of generating power that could be used in remote areas at very little cost. They add that microbial fuel cells are an important step in growing pressure to reduce reliance on fossil fuels and greenhouse gas emissions. The Bath team worked with Queen Mary University of London and the Bristol Bioenergy Centre.

The cell uses the natural biological processes of electric bacteria to turn organic matter (including urine) into electricity. The process requires urine to pass through the cell to cause the reaction; electricity is generated and then either stored or used immediately to power devices.

According to the research, a single microbial fuel cell can currently generate 2 watts per cubic metre, which is enough to power a mobile phone, and the team concedes this is not comparable to available alternatives such as hydrogen or solar fuel cells. The advantage, however, is low production costs and the use of human waste as a fuel, which is guaranteed never to run out. They aim to improve the power output through design optimisations.

Senior Lecturer in the Department of Chemical Engineering Dr Mirella Di Lorenzo said the development is part of a broader solution.

“If we can harness the potential power of this human waste, we could revolutionise how electricity is generated.

“Microbial fuel cells can play an important role in addressing the triple challenge of finding solutions that support secure, affordable and environmentally sensitive energy, known as the ‘energy trilemma’.

“There is no single solution to this ‘energy trilemma’ apart from taking full advantage of available indigenous resources, which include urine,” she said.

It is envisaged that microbial cells would be particularly useful in developing countries and impoverished or rural areas.

The research has been published in Electrochimica Actacan and can be viewed online via this link.

Image credit: © iStockphoto.com/David Gallaher