The Government’s Committee on Climate Change has identified ‘significant scope for emissions reduction’ through anaerobic digestion (AD) technology in its new report.
Entitled Meeting Carbon Budgets – ensuring a low-carbon recovery, the committee’s second progress report to Parliament identifies four areas which require new policy interventions in order to reduce carbon emissions, including electricity market reform, buildings, transport and agriculture.
The report commented: “Our new analysis of the agriculture sector suggests that there is significant scope for emissions reduction through a range of measures relating to soils and livestock, and through AD, with emissions reduction potential exceeding the target set out in the Low Carbon Transition Plan.”
According to the report, up to a million tonnes of carbon dioxide emissions “could be saved from the installation of AD plants (converting agricultural waste to renewable energy) either in a centralised location or on-farm.”
The Scottish Agricultural College survey (on which the report was based) determined that centralised 5MW capacity AD plants which used a poultry manure digestate, could provide a potential reduction of almost 500,000 tonnes of CO2, while AD plants located on medium and large pig farms could save 90,000 and 30,000 tonnes of CO2 respectively.
Consequently, the report called for the wider uptake of farm and centralised AD plants in order to meet the next three carbon budgets, these targets include:
- An increased installation of 5MW AD plants on medium and large pig farms by the time of the first budget, rising to 14MW each by budget 3 in 2018-2022.
- An increased installation of centralised AD plants, with individual capacities of up to 11MW in time for the first budget, and up to 40MW by the third.
- Up to 20% (250kt) of poultry manures collected for AD treatment by budget one, rising to 70% (900kt) by the third.
ADBA chairman Lord Redesdale told MRW: “The Climate Change Committee has shown the potential of AD, but as an association we think they have underestimated the potential size of the market. The targets for 2020 could be met in the next five years from farm AD because of the number of applications in the planning system.
“ADBA welcomes the work on fertiliser and AD might well be one of the major contributors to reducing farm emissions through digestate.”
The report’s findings come days after Tristram Stuart called for wider support for animal consumption of food waste, rather than investment in AD.
Stuart warned against “pulling [food waste] down the waste hierarchy by putting in place such attractive fiscal incentives” for using AD. “Perhaps this should be balanced out by looking at the benefits of feeding food waste to livestock,” he said.