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Potential for Renewable Gas in the UK
A report prepared for the National Grid, The Potential for Renewable Gas in the UK, shows that renewable gas will significantly contribute to the UK's renewable energy and carbon reduction targets for 2020.
It shows that renewable gas can deliver a secure energy supply for the country and at the same time help in waste management and reduce the need for landfill waste disposal.
The National Grid report says that to deliver renewable energy in the future, the country must source it from a variety of areas, but to date the potential for renewable gas has been largely overlooked.
At present, the UK's renewable gas supply is mainly derived from landfill gas and sewage gas. At the moment 1.4 billion cubic metres of renewable gas are produced in the UK, meeting just one per cent of the country's total demand.
This gas is used to generate electricity because of the incentives contained in the Renewable Obligation Scheme, but the report shows that this is not the most efficient use of this resource.
At present it is just 30 per cent efficient in its use, but the report says that if it was delivered to the grid and pumped to homes the efficiency rate would rise to 90 per cent.
However, before it can be added to the national grid, the gas needs to be cleaned and upgraded, as is happening in other EU countries such as Germany, France and Austria.
To upgrade the gas to biomethane, Anaerobic Digestion is used for wet wastes such as manure and gasification is use to clean gas from dry wastes such as energy crops.
The UK demand for gas is at present about 97 billion cubic metres with a residential demand of 35 billion cubic metres, and the report says that renewable gas could contribute between five per cent and 18 per cent to this total UK gas demand. In the ultimate scenario painted by the National Grid report, about 50 per cent of residential gas demand could be renewable.
This ultimate scenario, which the report describes as the "Stretch" scenario, shows that renewable gas could provide 18 billion cubic metres or about 10 per cent of the UK's total needs and two thirds of the government target for renewable energy of 15 per cent by 2020.
Source - National Grid plc
To deliver this proportion of renewable gas by 2020, the government would have to find £30 billion, with £20 billion of this being spent on renewing the infrastructure to handle the waste.
However, the report points out that this is work that would have to be carried out in any case.
"Given that this could deliver two thirds of the 2020 renewables target, this cost compares very well with the likely costs of delivering other large scale renewables such as wind," the report says.
It adds: "The analysis indicates that the cost of delivering renewable gas to UK homes is likely to compare very favourably with other proposed solutions for heat such as retrofitting heat pumps or storage heaters to existing homes on the gas grid.
"Furthermore, although the cost of carbon abatement with renewable gas may be slightly higher, it must be noted that renewable gas represents a unique solution for heat in the UK."
The infrastructure to deliver the gas to the consumer is largely in place and is being upgrades and has been paid for by the consumer.
Source - National Grid plc
The report adds that it is not only a solution for heat but it also acts as a means of addressing waste management issues.
It says that whether renewable gas is used on the main grid or not, the infrastructure to handle the waste materials being produced already will have to be upgraded as less and less waste is allowed to go to landfill.
"Anaerobic Digestion (AD) and gasification are both good alternatives for treating waste," the report says.
Anaerobic Digestion is already well established and although gasification is not so visible, it represents a better alternative to incineration, as far as emissions are concerned.
The report calls on the government to adopt a series of policies to press the cause for renewable gas.
It calls for:
- A commercial incentive for renewable gas producers to upgrade and inject their gas into the grid rather than generate electricity.
- A comprehensive waste management policy for the UK.
- A regulatory framework to provide incentives and to clarify roles and responsibilities of the gas transporters regarding renewable gas connections
- Continued support for research and development in renewable gas and upgrade technology.
February 2009
