Cost of abating greenhouse gas emissions from UK dairy farms by anaerobic digestion of slurry

Abstract

As a sector, agriculture in the UK is responsible for 43% of the methane (CH4) and 80% of the nitrous oxide (N2O) emissions, greenhouse gases (GHG) with global warming potentials of 21 and 310, respectively. The UK government is providing financial subsidies to reduce GHG emissions, particularly in energy production. These subsidies primarily come in the form of feed-in tariffs (FITs) and renewable heat incentive (RHI) to the renewable energy industry. Given that the traditional, fossil-fuel based energy industry’s GHG footprint is 96% in the form of carbon dioxide (CO2), a policy based on renewable electricity and heat production is primarily rewarding CO2 abatement and fossil fuel substitution. This is appropriate for most renewable energy technologies except anaerobic digestion (AD) which, besides producing energy, also has the potential to abate substantial amounts of CH4 and N2O. Dairy farms produce large quantities of cattle slurry which are suitable for AD but have low energy potential, thus providing poor economic return on capital investment even after claiming the subsidies available. An alternative subsidy could be provided by marginal abatement cost (MAC) which gives a value for GHGs abated. This research shows that after incentives dairy farmers bear a marginal abatement cost of £27 tonne-1 CO2 eq. abated, a key factor in low uptake of on-farm AD in the UK.

More information

Identifiers

ORCID for C.J. Banks: orcid.org/0000-0001-6795-814X

Catalogue record

Export record