The technique also reduces methane emissions

Jan 4, 2007 08:16 GMT  ·  By

Bull shit has got a valuable meaning.

Because it may have turned in the latest weapon in the fight against global warming.

The Walford and North Shropshire Agricultural College farm already uses methane from the dung discarded by its dairy herd to get power. The herd is housed for eight months a year and the shit is collected and pumped into a digester, where it is converted into methane and used to power a generator. The amount of energy produced is enough to run the farm. "Everything that comes out of the back end of an animal goes in [the digester]. We actually get enough energy to supply the farm's electricity for a year", said Adrian Joynt, farm manager.

"If you are going to put food in one end of the cow, we have to accept what comes out of the other. It's about what we do with it."

"We can either spread it on the field or we can put it through this digester and get the methane gas out of it."

The methane producing digester not only provides electricity, but it also decreases the methane emissions. Methane accounts for around 7% of the UK's greenhouse gas emissions, and about 25 % of it comes from the ruminant livestock, cattle and sheep. "Anaerobic digestion is a great idea - not least because manure from animals is also a major cause of water pollution", said Roger Higman, of the ecological association Friends of the Earth.

The digester works by collecting the cow's dung, in liquid form, which is then pumped into an airtight tank and heated to a temperature of 35C (95F), at which methane producing bacteria are most efficient. The methane produced feeds an engine attached to a generator which produces electricity.

The heat resulted from burning the gas is used to warm the cow dung to the level required by the bacteria. The ecological technology is used at more than 1,000 farms in Germany, but only very few in the UK, and, of course, is efficient in conditions of intensive cattle farming.