A “wee” Bit of Power

Article  \  26 Jul 2013

Today’s digital high tech modern age has a huge demand and reliance on energy sources.  Scientists are always searching for new clean green technologies to meet the increasing demands of the developed world’s energy consumption, while reducing or avoiding further pollution of the environment.[1,2] 

A team of researchers at Bristol Robotics Laboratory and the University of the West of England in the UK, reported that they were able to harness electricity from the action of microbial fuel cells on the urea in urine.[3, 4]  Urine is seen as a major source of nitrogen and phosphorus pollution of waterways, so its reduction is environmentally beneficial. 

Microbial fuel cells (MFCs) have been around for a long time, and convert chemical energy to electrical energy using microorganisms (for a brief summary, refer to [5]).  In MFCs the fuel, in this case urea, is reacted with the oxygen in the air by the microorganisms to produce carbon dioxide, water, nitrogen and electricity as waste by-products.  Given that the global production of urine runs into trillions of litres, this is seen by the group as a breakthrough in this type of technology. 

The Bristol group reported that this was the first instance of being able to show urine as an abundant fuel for the generation of electricity.[3]  However, more recently, the team have reported that they have successfully generated enough electricity from their MFCs, using urine, to power a mobile phone to a level to be able to make a phone call, browse the internet, and send a few text messages.[1, 6]  While the technology still requires further development to fully charge the phone, the authors suggest that in future, this type of technology may (through specially modified toilets) be able to generate enough electricity to power electric showers and lighting.

The team filed a patent application in 2012 with claims directed to the apparatus and arrangement of the microbial fuel cells and methods for the generation of electrical power.[7]  The application has not yet entered national phase so we wait with interest to see what further developments are made in this area of technology.

So, will urine be the next clean green renewable source that answers the world’s energy demands, or is the thought of generating electricity from urine, just too “yuck” for most?

  1. http://www.bbc.co.uk/news/uk-england-bristol-23333533.
  2. http://www.bbc.co.uk/news/uk-scotland-edinburgh-east-fife-11023725.
  3. Ioannis A. Ieropoulos et. al.,Phys. Chem. Chem. Phys., 2012, 14, 94-98; RSC publications, http://pubs.rsc.org/en/content/articlelanding/2012/cp/c1cp23213d.
  4. http://www.brl.ac.uk/researchthemes/bioenergyselfsustainable/urine-tricity.aspx
  5. http://en.wikipedia.org/wiki/Microbial_fuel_cell.
  6. Ioannis A. Ieropoulos et. al., Phys. Chem. Chem. Phys., 2013; accepted manuscript, published online 16 July 2013; RSC publications http://pubs.rsc.org/en/content/articlelanding/2013/cp/c3cp52889h; DOI: 10.1039/C3CP52889H.
  7. WO2012/120314, http://patentscope.wipo.int/search/en/detail.jsf?docId=WO2012120314&recNum=1&maxRec=1&office=&prevFilter=&sortOption=&queryString.