Anaerobic Digestion


What is Anaerobic Digestion (AD)?

Anaerobic Digestion (AD) is a sub-division of the RE science referred to as ‘Biomass’.

AD is the conversion into biogas and digestate, through natural decomposition by micro-organisms in the absence of oxygen, of any non-woody organic material.  The favoured organic wastes found on farms include animal manure, silage, dairy washings, spoilt animal feed (or grain), to name but a few with each material having a unique biogas yield potential.   Uses of biogas include:

  • Fuel to drive Combined Heat & Power (CHP) engines providing electricity and heat (circa 80% combined efficiency)
  • Fuel for boilers providing heat only (90% efficiency)
  • Further processing, including compression to produce biomethane for use as a vehicle fuel (immature technology in the UK)
  • Further processing to produce grid-quality biomethane that is injected into the national gas grid (a new concept to the UK gas industry)

Useful links for Anaerobic Digestion;

DEFRA AD information source:

National Non-Foods Crop Centre (NNFCC):

The official AD site of the NNFCC:

A Detailed Economic Assessment of Anaerobic Digestion Technology and its Suitability to UK Farming and Waste Systems 2nd Edition (Andersons):

The DEFRA NVZ portal:

Renewable Energy Concepts portal:

ODPM Planning & Policy Statement 1 – Delivering Sustainable Development:

ODPM Planning & Policy Statement 7 – Sustainable Development in Rural areas:

The Carbon trust:

General planning advice can be found at:

Interactive householders guide:

Department of Energy & Climate Change:

Environment Agency: