Farming fuel of the future

Your milk could soon be delivered by a tanker running entirely on manure, according to the Royal Agricultural Society of England (RASE). In its new report, Refuelling the Countryside, it encourages readers to imagine a future in which the 90 million-100 million tons of slurry produced on British farms each year are turned into sustainable forms of energy and low-carbon fuel as a matter of course, reducing outgoings and providing landowners with extra income.

Slurry from livestock is converted into biogas through anaerobic digestion (AD) or the breaking down of organic matter in an airless environment. The energy produced can then be used on site or exported as electricity or heat energy. Last year, after sustained lobbying from the NFU, Defra launched a £3 million scheme allowing farmers to apply for grants to help them fund the building of small-scale AD plants. The NFU says the response has been ‘enthusiastic' and, now, RASE is urging landowners to think bigger.

It's possible, for example, for the energy produced by AD to be turned into biomethane and used as a transport fuel. Tractors running on biomethane are in operation in Germany, Scandinavia and the USA and the report suggests that local delivery vehicles, such as milk tankers, could also one day be powered by it.

‘Although there will be no single answer suitable for every farm, huge opportunities are available and these will improve as the technologies advance,' says RASE chief executive David Gardner. The organisation envisages farmers making a significant contribution to Britain's renewable-energy supply in years to come, exporting electricity to the National Grid and supplying holiday cottages, industrial estates and village buildings with heat generated using AD.

However, sceptics point to stumbling blocks such as Grid-connection issues, the costs of setting up and maintaining plants and the fact that cattle slurry is generally only available when animals are indoors during the winter.

‘Landowners need to assess the opportunities for renewables with a cool head,' advises Dr John Constable, director of the Renewable Energy Foundation. ‘Experiment, by all means, but proceed with caution and don't burn any bridges. Subsidies to renewables are a Government market distortion, in effect paying farmers to ignore the food sector, which is, arguably, where the comparative advantage of land really lies.'

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