Turning poo into power

Cow Power - not an idea to be poo pooed! Decomposing livestock manure produces greenhouse gases that contribute to 4% of the USA’s emissions but if converted into biogas, it could power millions of homes.

Biogas productiong from manure re-uses a waste product

Researchers in Texas, livestock capital of the US, have quantified the national amount of renewable energy that cattle and other livestock could produce and outlined what methods could be used to turn poo into power.

Authors of the paper, Dr Michael Webber and Amanda Cuellar from the University of Texas, write: “In light of the criticism that has been levelled against biofuels, biogas production from manure has the less-controversial benefit of reusing an existing waste source and has the potential to improve the environment.”

Many farmers in the US are already harnessing cow power - they collect the methane given off by fermenting cow manure and use it to generate electricity. The procedure is relatively simple: manure is stored in huge tanks - anaerobic digesters - which are deprived of oxygen producing a large volume of biogas. Using this method on a large scale in the USA could produce 100 billion kilowatt hours of electricity, enough to power for millions of people.

However, the authors point out that like many energy sources, the problem is in the efficiency and logistics of implementation.

By Leila Sattary