Waste not, want not

Half of Britain’s domestic gas needs could be met by turning waste into biogas, according to the latest report from National Grid.

The UK currently generates around one per cent of its energy from biogas produced by landfill and sewage plants.

This gas, however, is used to generate electricity at efficiency levels of around 30 per cent.

According to the report, if it were injected into the gas grid, then this could be delivered straight into consumers’ homes and utilised for heating at efficiency rates in excess of 90 per cent.

This would help achieve renewable energy targets by 2020.

Biogas can be produced via anaerobic digestion, which turns wet waste like sewage into biomethane, and gasification, which is typically used for drier wastes.

Following Europe’s lead (where biomethane is already being injected into gas grids) the report claims that these processes will allow Britain to reach its energy targets by 2020.

Total gas demand in the UK is approximately 97bcm, with residential demand at around 35bcm.

National Grid states that renewable gas could contribute between five and 18 per cent of this demand. In the future, this figure may rise to 50 per cent once renewable technologies are established in Britain’s infrastructure.

Janine Freeman, head of National Grid’s Sustainable Gas Group, said: ‘Biogas has tremendous potential for delivering large-scale renewable heat for the UK but it will require government commitment to a comprehensive waste policy and the right commercial incentives.

‘Biogas has benefits on so many fronts. It is renewable and could help to meet the target of 15 per cent of all our energy coming from renewable sources by 2020. It provides a solution for what to do with our waste with the decline in landfill capacity and it would help the UK with a secure supply of gas as North Sea sources run down.’

While biogas is similar in price to other renewable energy sources, it has the added benefit of being compatible with the existing gas infrastructure. The National Grid believes that the main challenge will be to ensure effective commercial incentives are put in place in order to use biomethane for gas rather than electricity.