Humans, like all living things, produce a lot of waste, but scientists are beginning to show us that it doesn't need to end there. In terms of trash waste, Sweden burns more than two million tons of the stuff annually—almost 50% of the garbage produced by the country—in order to generate electricity. But that's not the only kind of waste that's proving useful. In the U.K., human poop-powered buses took to the streets last November in a bid to reduce emissions and fossil fuel usage. And now, on a similar theme, scientists working at the University of the West of England (UWE) have developed a “Pee-Power” toilet that, amazingly, generates electricity from urine.
Although the prototype urinal currently resides outside of the Student Union Bar, where it is sure to receive a lot of visitors, the researchers behind the invention hope that it can do more than amuse and bewilder drunken students. The energy generated by the system is used to light up the cubicle, which would make it an ideal addition to refugee or displaced person camps that often don’t have electricity. But it isn’t just stumbling around at night that is a problem; these places are often dangerous for women after hours as many are abused or molested in dark areas such as cubicles. The researchers are therefore hopeful that these toilets will help make it safer for women to use the loo at night.
So how do they work? The cubicles are fitted with stacks of microbial fuel cells (MFCs) that are based on microbial metabolism. The live bacteria inside the fuel cells use urine as fuel for their growth and maintenance, but as a bonus for us they produce electricity as a byproduct.
“The MFC is in effect a system which taps a portion of that biochemical energy used for microbial growth, and converts that directly into electricity—what we are calling urine-tricity or pee power,” project leader Ioannis Ieropoulos said in a news release. “This technology is about as green as it gets, as we do not need to utilize fossil fuels and we are effectively using a waste product that will be in plentiful supply.”
Importantly, MFCs are also extremely cheap: each one costs around £1 ($1.51) to make. According to Ieropoulos, setting up a unit like the prototype outside the Union will cost around £600 ($900), which is a relatively small price tag given that it is a lasting product.
The researchers are trying to encourage as many students into the urinal as possible for now, which has been designed to look like the toilets used in refugee camps run by the charity Oxfam. If the ongoing trial proves that the cubicles work well, then hopefully they can be installed in areas where they are needed.
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