Talk about recycling — scientists at a British university have come up with a way to charge mobile phones with that most ubiquitous of by-products, human urine. Yes, it’s pee power.
The team from the Bristol Robotics Laboratory, part of the University of the West of England (UWE), has been working for quite some time on their version of the microbial fuel cell (MFC) – a concept that goes back a century, but that has never quite become commercially viable. MFCs use bacteria to break down organic material and create power. The bacteria need the right “food” to generate a usable amount of electricity, and the UWE team reckons human urine ticks the right boxes.
To quote team leader Dr Ioannis Ieropoulos from a few years back, when the researchers were experimenting with creating stacks of these MFCs: “Urine is chemically very active, rich in nitrogen and has compounds such as urea, chloride, potassium and bilirubin, which make it very good for the microbial fuel cells.”
Fast forward to this week, and the team is talking major progress. MFCs don’t output much power and, until now, the researchers had only managed to accumulate very small amounts of power into capacitors for storage. Now they’ve successfully charged a Samsung handset enough to get some real – albeit limited – usage.
Here’s Ieropoulos again:
“So far the microbial fuel power stack that we have developed generates enough power to enable SMS messaging, web browsing and to make a brief phone call. Making a call on a mobile phone takes up the most energy but we will get to the place where we can charge a battery for longer periods. The concept has been tested and it works – it’s now for us to develop and refine the process so that we can develop MFCs to fully charge a battery.”
It sounds like a real breakthrough, particularly for environments such as rural areas in emerging markets, where power sources can be hard to come by, and where mobile phones are proving for many to be a bridge into the modern era. Indeed, some funding for this work has come from the Bill and Melinda Gates Foundation. The team also sees potential for powering lighting, razors and other such devices.
It should be noted that this isn’t the only way of harvesting power from pee. The other uses electrolysis in order to generate hydrogen fuel, but that comes with a couple of significant problems: firstly, hydrogen is explosive; and secondly, it takes a fair amount of power to split out the hydrogen molecules in the first place. The advantage of MFCs is that they are, urine input aside, relatively self-sustaining.
By David Meyer