The report looks at how all the biodegradable waste streams such as sewage, food and wood could be turned into biogas and injected into the gas distribution system.

At the moment there is a small quantity of production of biogas in the UK coming from landfill and sewage plants, but it is being used to generate electricity. The National Grid says these valuable waste resources could be used more efficiently by turning them into biomethane, which could meet 50% of the domestic gas needs and help achieve renewable energy targets for 2020.

Two processes are highlighted by the National Grid for producing the biogas: anaerobic digestion which turns wet waste such as sewage and animal manure into biomethane, and gasification which is better suited to drier wastes and energy crops.

In cost terms, it is estimated that biogas would be a similar price to other renewable energy sources. However, because the UK already has an extensive gas grid, there would be little need for disruptive infrastructure development.

The report concludes that there are no insurmountable technical difficulties to delivering biogas. The main hurdle will be to get the right commercial incentives in place so waste can be turned into biomethane for gas grid injection rather than electricity. This needs to be allied with a comprehensive waste management policy.