Poo power: Stanford engineers harness electricity from sewage
The researchers behind a novel invention announced yesterday call their discovery a "microbial battery." That's a lot more marketable than "poo power," which is essentially what we're talking about here.
Engineers at Stanford University have discovered a new way to draw electricity from sewage. The prototype they have created is a proof of principle, but the team hopes that the discovery could eventually be used to offset the electricity used to treat wastewater, a significant expenditure in developed countries.
The microbial battery harnesses the power of unique bacteria that produce electricity as they break down biological waste. "Exoelectrogenic" bacteria slough off electrons as they convert animal and plant matter into fuel. The microbes cling to the negative electrode of the devide and the energy they produce is captured by the positive electrode, which is made of silver oxide.
The engineers think their device can release 30 per cent of the energy that's locked up in wastewater, but lots more work has to be done. Silver, for example, is too expensive to scale up significantly, so they are looking for other materials.
The research was published in Proceedings of the National Academy of Sciences.
Kate Allen is the Star's science and technology reporter. Find her on Twitter at @katecallen.