What is it?
Anaerobic digestion harnesses the natural process of organic materials (such as agricultural manure, slurry, food waste, miscanthus or maize crops) being broken down by bacteria.
How does it work?
Organic matter is broken down by bacteria in the absence of oxygen in a closed vessel. This process produces biogas that can be used to generate both heat and power.
The biogas can be refined further with carbon dioxide and other impurities being taken out to produce biomethane which can be used to fuel transport, or injected into the natural gas grid network.
The residue from the process is known as digestate and can be used as a liquid fertiliser, or separated into a fibre and sold for soil conditioning, and the liquor can be applied to farmland as a low grade fertiliser.
Is it suitable?
Anaerobic Digestion can be carried out in a small scale system, for example located on a farm and operated by farmers, or serve businesses (or clusters of businesses) that have access to a large amount of food waste.
Alternatively it can be carried out in large centralised systems, for example to treat municipal food waste being diverted from landfill by local authorities.
If the biodegradable material fed into an anaerobic digester is a waste (manure, slurry, food waste), the resultant digestate (residue) is subject to waste regulation controls.
What are the benefits?
- Anaerobic digestion is a well proven renewable energy and waste management technology.
- Receive payment for energy exported to the grid: Small scale generators of electricity (up to 50KW) can apply to a Smart Export Guarantee (SEG) Licensee to receive payment for the electricity exported back to the National Grid. SEG Licensees offer different rates, therefore generators should shop around to find the best SEG rate. To see the current list of SEG Licensees click here.
- It provides an environmentally safe waste management/ disposal method and generates clean power.
- It reduces the amount of greenhouse gas emissions by capturing methane from decomposing organic materials.
- An additional income can be gained from the sale of the digestate.
- Systems installed by an accredited contractor (MCS approved) can earn you money from the Smart Export Guarantee (SEG)
Rural Community Energy Fund
The Rural Community Energy Fund (RCEF) is a £10 million programme which supports rural communities in England to develop renewable energy projects, which provide economic and social benefits to the community.