The age of “pee-power” is here – and it may revolutionize the free flow of power in the developing world.
Researchers in the UK have created a Microbial Fuel Cell (MFC) that turns the organic compounds in urine into electricity.
Their small innovation is strong enough to power a cell phone, and can be mass produced for less than $3 apiece.
“Renewable ‘pee-power’ is a brilliant idea, and its use in developing countries will have huge positive impact on people’s lives in areas of energy poverty,” said Dr. Tim Mays, Head of the Department of Chemical Engineering at the University of Bath.
The idea of “pee-power” began with plans of tapping regular wastewater as a power source. The plan was to harness specific bacteria that generate electricity when they eat organic compounds in in the water.
Scientists quickly realized plain urine would actually work better in the lab than raw sewage and storm run-off.
“Urine is a specific type of wastewater that actually has some advantages for lab-scale tests over other types of wastewater. It’s clear and does not contain suspended solids,” explained Dr. Mirella Di Lorenzo, a researcher in Bath’s Department of Chemical Engineering.
Those clear and solid-free qualities helped Dr. Di Lorenso’s team to shrink the size of their MFC over previous designs. It was a huge leap forward from just three years earlier.
In 2013, Dr. Ioannis Ieropoulos of the Bristol Robotics Laboratory had proven the idea of “pee-power” was possible using an array of fuel cells.
That device, which could also power a cell phone, was larger than a car battery (below), but the University of Bath device is only slightly larger than a postage stamp (pictured above).
The fuel cell works like this: bacteria inside the cell break down organic matter floating in the urine into electrons. An electrode gathers the electrons, sending them flowing though through a circuit and cathode which generates an electric current.
“The process takes the waste we naturally produce,” Dr. Ioannis said, “and it converts it directly into electricity.”
An average adult will produce a quart-and-a-half of urine every day, and as much as two percent of a nation’s energy output can be spent on wastewater treatment.
“We aim to transform wastewater from an energy ‘issue’ into an energy ‘source,” Dr. Di Lorenzo said. “MFCs do not produce any harmful gasses, work at ambient temperature and pressure and therefore their design is really easy. Most of all they use as fuel something we will never run out of.”
She already sees applications where one day smart toilets could help supply power to cities, homes, or remote villages, or run water quality sensors in developing countries, using the very water it monitors as a power source.Share this article: