Cows can earn their keep and keep the lights on
Pandjenergy.co.uk, April 1st
A typical dairy farm could supply most of the electricity it needs to milk the cows, by converting their manure into energy
And it would help the Government to hit green energy targets and cut greenhouse gas emissions, according to scientists from the universities of Southampton and Reading.
A dairy cow can produce up to 64kg of manure per day, so if they are housed inside every night and farmers collect half of all the manure they produce, it means a single animal could make over 11 tonnes of manure a year.
It is too wet to burn but it can be put into a special machine called an anaerobic digestion plant.
This keeps the manure warm in an air-tight tank until some of it turns into methane gas which can be burnt to produce heat or electricity.
The scientists think one cow could generate enough methane gas to create 1,000 kilowatt hours of electricity per year – equivalent to three months’ electricity consumption for an average household!
A US farmer recently installed a digester to convert the manure of its 570 cows into biogas. Along with producing enough biogas to generate electricity at the rate of 920,000kWh per year, the digester produces high-quality bedding that makes the cows feel more comfortable.