Anaerobic Digestion and large-scale intensive livestock farms
27 December 2011
A new report on Anaerobic Digestion (AD) and large-scale intensive livestock farms, which was commissioned by the Soil Association and the World Society for the Protection of Animals and written by an independent consultant, shows that with large-scale AD units – such as that proposed by Midland Pig Producers at Foston - potential benefits are extremely unclear, or may be non-existent.
The Soil Association has sent this report to Derbyshire County Council today along with a covering letter that summarises the conclusions of the report, and its potential impact on AD developments when used as part of the justification for mega-dairies like Nocton or huge pig developments like Foston.
In September 2010, Carter-Ruck acting on behalf of Midland Pig Producers (MPP), told the Soil Association to withdraw our evidence against the proposed development at Foston, which we did not do. Amongst other things, Carter-Ruck said we were 'taking no account of' the fact that the manure at Foston will 'be processed through a bio-digestive process' that produces an 'odourless, pathogen-free, rich and easily absorbent fertiliser'. On their website, MPP say about the AD unit that: "This innovative development will inextricably link agriculture and environmentally friendly power generation".
The AD unit will cost a third of the whole development, so it represents a huge investment, and will be eligible for significant support from the tax payers through the feed in tariff system. Using MPP's own figures, it will only reduce greenhouse gasses by 17% at most. However, the report states that the experience from a number of other countries, particularly Germany, where AD units have been in use for longer than the UK, is that if AD units are going to be made to work economically, they need to use specially grown maize as a fuel. If this happens, it makes a nonsense of claims that this sort of large-scale AD unit is good for the environment. The report also highlights a number of other uncertainties and technical issues that suggest that the 17% figure may not be reliable.
Therefore the Soil Association is now urging the County Council not to rely on the claims being made by MPP in respect of the AD unit. This report shows that with large-scale AD units, potential benefits are extremely unclear, or may be non-existent.
Similar arguments do not apply to small AD systems which are linked with local production of green waste or biomass, both of which are much more efficient fuels than pig or cow slurry - small scale use of technologies like this can clearly have significant environmental benefits.
The Government's Climate Change Committee (CCC) came to similar conclusions in their review of bio-energy, published on 7 December 2011. They said that they had real reservations about large-scale developments, but small scale applications were generally fine. They also noted that maize (and, at a global level, sugar cane) are by far the most efficient fuels. In addition, they said that in respect of large scale bio-energy projects, without carbon capture (not currently available) when the resulting bio-gas or bio-ethanol is burnt, the technology does not provide clear climate change benefits. The Chair of the CCC, Lord Adair Turner, said that unless we get the sustainability framework right we could "easily end up doing things that in overall effect are negative", that there is "some evidence that biofuels are one of many significant factors driving food price spikes in recent years", and that we need stronger regulation "to make sure bio-energy is truly low-carbon". Currently, the UK Government are uncritical supporters of large-scale AD developments.
The Soil Association is concerned that we are in danger of heading down exactly the same track that the European Commission took with biofuels, thinking that because something turns biological products like animal waste or crops into methane gas or ethanol, this must be good for the planet, and it deserves millions of pounds of public money being poured into it. Many are now struggling to reverse decisions on biofuels taken in haste with inadequate information.