Anaerobic Digestion

You may be able to treat your biodegradable waste using anaerobic digestion. This uses natural bacteria to convert waste into:

  • biogas, which can be used to generate electricity and/or heat
  • liquid, which can be used as a fertiliser
  • solid, which can be used a soil improver.

Increasingly AD is being used to make the most of our waste by turning it into renewable energy.

What you must do

Operating an anaerobic digester

If you operate an anaerobic digester to treat food waste you may need:

Exemptions in Northern Ireland

You may need to register a paragraph 13 exemption for composting and storing biodegradable waste in Northern Ireland. If you have an exemption, you must comply with the exemption conditions.

DAERA: Paragraph 13 Composting and storage of biodegradable waste

If your waste includes animal by-products you must have approval for your anaerobic digester from Animal Health in Scotland or the Divisional Veterinary Offices (DVO) in Northern Ireland.

Animal by-products and food waste

Low risk waste activities in Scotland

In Scotland, if you carry out anaerobic digestion of less than, or equal to, 1 tonne of waste including Animal By-Product food waste at any one time in an enclosed system you may not need an authorisation from SEPA, if you collect and use the gas produced, and only treat the following wastes in the enclosed system:

  • Plant tissue waste
  • Horse and farmyard manure only
  • Fully biodegradable animal bedding
  • Animal tissue waste
  • Materials unsuitable for consumption or processing
  • Biodegradable kitchen and canteen waste
  • Biodegradable waste from markets only

SEPA low risk waste activities 

Burning biogas as fuel

If you burn biogas you must have an authorisation.

In Northern Ireland, you will need a:

  • waste management licence or exemption for an appliance with a rated thermal input of less than 1MW
  • a pollution prevention and control permit for new appliances with a rated thermal input of 1 MW or more. Plants with a thermal input rating of between 1 MW and 20 MW that were put into operation before 20 December 2018 will need a PPC permit by 1 January 2024 or 1 January 2029 depending on the size of the plant. 

Pollution prevention and control permits

Waste management licences

In Scotland, you may need an EASR authorisation. This will be either an:

  • EASR registration, for one or more electricity generators with a combined thermal input of more than 1 MW (from 1 January 2029)
  • EASR permit, for operating a medium combustion plant with a rated thermal input equal to or more than 1 MW and less than 50 MW, or for the combustion of fuels in installations with a total rated thermal input of 50 MW or more

SEPA: Combustion of fuels

Further Information

 

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