A Herefordshire poultry producer is set to fire up a new large-scale anaerobic digestion(AD) heat and electric plant which will consume 1,700t of manure per annum, powering up to 450 homes and replacing all oil and gas used in heating on farm.
The facility at Great Ynys Farm will be switched on in early August and is expected to be able to power and heat a 90,000-bird broiler unit, producing 90% surplus energy, which will be sold to the grid.
The plant will have a capacity of 700t of poultry litter, 1,000t of cattle slurry, all mixed with 3t of maize silage per annum. Cattle slurry will be sourced from surrounding dairy farms while some of the maize will be grown on 125 acres of arable land which surround the farm.
Mixing manures and adding maize results in a mix which digests more efficiently and doesn’t build up large amounts of ammonia, halting the digestion process (see Poultry World, July 2011, p33).
Also, 5,000cu m of odourless liquid fertiliser will be produced from the plant each year that will be spread on the farms’ arable land to improve the yields on the maize crop.
The combined heat and power system attached to the AD plant will provide 250kW of electricity and 200kW of heat, qualifying under the Feed-in Tariff and Renewable Heat Incentive for payments of 14p/kW on all electricity and 6.5p/kW for heat used on site.
The farm’s new green power company is called Ynergy, and director Susan Shakesheff said the move to anaerobic digestion would improve sustainability, while securing a new income stream. “We are able to find a superior alternative for utilising our chicken litter and are helping neighbouring dairy farmers to recycle their cattle slurry,” she said.