Cow dung has provided human beings with fuel for millennia. Now, thanks to research conducted by Ohio State University, it could become the foundation for future notebook power plants.

To be fair, it's not the manure per se that's the power source, but the bacteria crawling through it.

According to researcher Ann Christy, Associate Professor of food, agricultural and biological engineering, the bugs in 0.5l of bovine gastric juices can generate 600mV - half the voltage needed to power up a AA-sized rechargeable battery. The voltage arises from electrons freed when the bacteria digest cellulose in the cow's gut.

Since it's easier to extract the bacteria after they have left the cow's intestinal tract, fecal matter looks like a far better source that the stomach fluid.

Indeed, the Ohio State researchers ran a dung-packed fuel cell for "well over 30 days without a decrease in the voltage output", said co-researcher and Ohio State graduate student Hamid Rismani-Yazdi. The cell generated 300-400mV.

“While that's a very small amount of voltage, the results show that it is possible to create electricity from cow waste,” Christy said.

The downside is size: the experimental fuel cells comprised two cylinders each 30cm high and 15cm in diameter. There's also the problem of how much power the bugs generate.

“Although it's too early to tell if this kind of fuel cell can produce significantly more electricity," said Christy, "the fact that the [stomach] fluid worked in our study means that there are additional electricity-producing microbes that we have yet to identify." ®

Related stories

Samsung powers ahead with fuel cell tech (13 August 2007)
http://www.reghardware.co.uk/2007/08/13/samsung_sens_q35/
Wind-powered phone-charger coming to market? (21 June 2007)
http://www.reghardware.co.uk/2007/06/21/wind-powered_phone_charger_update/
Boeing to test fuel-cell powered publicity plane (30 March 2007)
http://www.theregister.co.uk/2007/03/30/boeing_dont_really_like_fuel_cells/
Cow poo: the building material of the future? (12 February 2007)
http://www.theregister.co.uk/2007/02/12/cow_poo/
Boffins build fuel cell to power iPod (3 July 2006)
http://www.reghardware.co.uk/2006/07/03/voller_fuel_cell_abc/
Casio preps 'highest' power density portable fuel cell (15 May 2006)
http://www.reghardware.co.uk/2006/05/15/casio_portable_fuel_cell/
Samsung preps four-hour fuel cell for portable video players (31 January 2006)
http://www.reghardware.co.uk/2006/01/31/samsung_four_hour_fuel_cell/
Sanyo pitches 'ready to use' rechargeable batteries (3 November 2005)
http://www.theregister.co.uk/2005/11/03/sanyo_eneloop/
Carrier to offer fuel-cell mobiles by March 06 (30 September 2005)
http://www.theregister.co.uk/2005/09/30/kddi_fuel_cell_mobiles/
LG to ship notebook fuel cell in 12 months (29 September 2005)
http://www.theregister.co.uk/2005/09/29/lg_chem_fuel_cell/
German inventor denies cats-for-fuel story (15 September 2005)
http://www.theregister.co.uk/2005/09/15/cats_fuel_diesel/
Oz farmers to enjoy internet cattle monitoring (24 August 2005)
http://www.theregister.co.uk/2005/08/24/australian_net_cattle_monitoring/
Battery-boosting body offers fuel cell advice (24 June 2005)
http://www.theregister.co.uk/2005/06/24/battery_body_fuel_cell_advice/
Scientists push bacteria to quadruple hydrogen production (26 April 2005)
http://www.theregister.co.uk/2005/04/26/bacteria_hydrogen_production/
Hydrogen cars by 2012 says DaimlerChrysler (17 March 2005)
http://www.theregister.co.uk/2005/03/17/hydrogen_cars/
Nokia nixes fuel cells development project (4 March 2005)
http://www.theregister.co.uk/2005/03/04/nokia_ditches_mobile_fuel_cell/
NEC to show laptop with built-in fuel cell (19 October 2004)
http://www.theregister.co.uk/2004/10/19/nec_notebook_fuel-cell/
Hydrogen-powered cars creep forward (15 October 2004)
http://www.theregister.co.uk/2004/10/15/nano_hydrogen_catflap/
Scientists suck hydrogen from sunflower oil (27 August 2004)
http://www.theregister.co.uk/2004/08/27/fuel_sunflower_oil/
Nanotech aids green hydrogen production (13 August 2004)
http://www.theregister.co.uk/2004/08/13/green_fuel/
Toshiba touts pump-free fuel cell for MP3 players (25 June 2004)
http://www.theregister.co.uk/2004/06/25/tosh_fuel_cell/
Sulphur fuels battery breakthrough (12 May 2004)
http://www.theregister.co.uk/2004/05/12/lithium_sulfur/
Hitachi readies fuel cell for PDAs (12 December 2003)
http://www.theregister.co.uk/2003/12/12/hitachi_readies_fuel_cell/
Toshiba demos cellphone fuel cell (7 October 2003)
http://www.theregister.co.uk/2003/10/07/toshiba_demos_cellphone_fuel_cell/