a division of NEPIC

Heat

NEPIC, in conjunction with National Grid and Centrica commissioned a feasibility study to review the use of Bio SNG delivered via the gas grid as a way to decarbonise road transport and heat. Some of its conclusions were that it offers the possibility of substantial scale renewable methane production and the major processes required to produce it can be identified and assembled using existing technologies. This product has an application either as a transport fuel, or for industrial or domestic heating. The infrastructure for energy delivery is in place with the existing gas grid.

Renewable gas will have a key role to play in the future; the ENA/Redpoint study of November 2010 suggested that scenarios involving the continued use of gas could be up to £700bn less expensive than options that rely on complete electrification. Biomethane from anaerobic digestion is valuable but limited, and Bio SNG could potentially deliver much larger quantities of renewable gas.

Bio-SNG is formed during the conversion of thermally-derived synthetic gas into methane. Unlike biomethane produced by anaerobic digestion, feedstocks can include more durable material such as woody biomass and wastes that are not broken down in traditional anaerobic digester plants.  Although anaerobic digestion of organic material has been widely accepted as an important renewable energy technology, the production of Bio-SNG is required to move to higher levels of fossil fuel replacement.

Whilst the study was considering the use of Bio-SNG as a vehicle fuel, it showed that an attractive option may be to use Bio-SNG for domestic heating. Bio-SNG is a particularly attractive renewable vector as it can be readily utilised in existing applications - CNG (Compressed Natural Gas) vehicles or efficient condensing gas heating appliances. This compares favourably with the use of other renewable vectors which can impose significant demand-side constraints, which hinder take-up.

For heating, the study shows that the cost per tonne of carbon abated appears to be lower than domestic and commercial biomass boilers and ground source heat pumps. Similarly, for transportation, with the Bio-SNG delivered by the gas grid to customers and then made into CNG for use as a road fuel, the cost per tonne of CO2 abated appears to be significantly lower than the cost for electric vehicles and is a credible option for trucks where the electric option is not practical. 

The key advantages of Bio-SNG are: the ability to convert both woody biomass and wastes into fungible Bio-SNG; the utilisation of the existing gas grid which allows highly efficient transfer of energy from the Bio-SNG plant to the consumer; and finally the use of efficient heating appliances such as condensing boilers.

Along with all unconventional energy infrastructure development there is a need for novel financing strategies, as well as the necessary support regime. In terms of taking forward a UK demonstration project, the Study indicates that Teesside is a highly attractive location because of its chemical industry, ability to utilise waste heat and co-products and extensive high pressure gas grid.

North East Bioresources & Renewables, c/o NEPIC, Room H224, Wilton Centre, Wilton, Redcar, TS10 4RF | T +44 (0) 1642 442 560