Human urine has been turned into all sorts of things over the centuries. Alchemists distilled phosphorous from it, it was once used for the production of gunpowder, tanners employed it in great vats to tan hides, and it has served as the basis of a myriad chemical substances, including the first types of plastics. Now yet another use for this ubiquitous liquid has been created. Researchers working at the University of the West of England (UWE Bristol) have built a urinal that converts urine directly into electricity.

Not the first modern reuse of urine mooted in the modern era, recycling this liquid has been suggested for everything from creating hydrogen for powering cars to creating biological concrete – and even for distilling a type of sports drink. However, this latest prototype may be one of the most useful and easily-applicable yet, as it is proposed to power light cubicles in refugee camps, which are often dark and dangerous places particularly for women.

Not only is this prototype an ingenious way of providing electricity by using a set of microbial fuel cell (MFC) convertor stacks powered by urine, but it may also help to harness and reduce the vast amounts of waste liquid generated in refugee camps that often house many tens of thousands of people. This could help in reducing pollution and assisting in improving the sanitation and general living conditions, thereby relieving a little more stress factor from these already often over-burdened areas.

Based on earlier prototypes produced at UWE Bristol that were used to power mobile phones, the latest work is the result of a partnership between researchers at UWE Bristol and Oxfam. Led by Professor Ioannis Ieropoulos, at the Bristol Robotics Laboratory that originally built the microbial fuel cell used in these latest trials, the team has high hopes that the work will make a real difference to many of the people around the world displaced by war, famine, or natural disaster.

"We have already proved that this way of generating electricity works. Work by the Bristol BioEnergy Centre hit the headlines in 2013 when the team demonstrated that electricity generated by microbial fuel cell stacks could power a mobile phone. This exciting project with Oxfam could have a huge impact in refugee camps," said Professor Ieropoulos.

Staff and students are asked to donate as often as they can, which shouldn't be too much trouble with the prototype erected right outside the student union bar at the university. To ensure that the trial resembles real life as closely as possible, the toilets are built to look just like those supplied by Oxfam to refugee camps. Except that, in the interests of science and donator curiosity, there is also a clear plastic screen through which users may observe the MFC that turns the urine into electrical power.

"The microbial fuel cells work by employing live microbes which feed on urine (fuel) for their own growth and maintenance. 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," said Professor Ieropoulos. "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."

Getting the huge number of toilet/fuel cell combinations out to the field will be a big enough logistical problem in itself, let alone the cost of doing so. Which is why it is also exceptionally important that this technology be both affordable to create, and generate electricity for as long a period as possible. The team at UWE Britol thinks this is achievable.

"One microbial fuel cell costs about £1 (USD $1.50) to make, and we think that a small unit like the demo we have mocked up for this experiment could cost as little as £600 (USD $900) to set up, which is a significant bonus as this technology is in theory everlasting," said Professor Ieropoulos.

The short video below shows interviews with the UWE Bristol team and some pictures of the system in place at the university.

Source: UWE Bristol

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