National Grid is investigating the possible future reuse of some of its high pressure natural gas transmission pipelines to transport carbon dioxide from power stations and heavy industry to storage offshore.

Scotland and the Humber region in England have been identified as offering some of the best opportunities for Carbon Capture and Storage (CCS) in Europe, with power stations and other heavy industry close to the North Sea oil and gas fields which, when depleted, could provide storage for their carbon dioxide emissions.

CCS networks in Scotland and Humberside could together result in a reduction of up to 78 million tonnes of carbon dioxide (60 for Humberside and 18 for Scotland) going into the atmosphere every year. That’s equivalent to taking nearly all of Britain’s cars off the road.

Alongside this substantial reduction in greenhouse gas emissions, CCS would also bring benefits to security of electricity supply by allowing coal to remain part of a future diverse low carbon energy mix.

Coal generation, with its flexible output, could play a valuable role in meeting the UK’s future energy requirements alongside a large proportion of intermittent wind generation and large but inflexible nuclear generators.

National Grid is exploring opportunities to apply its expertise in gas pipelines to CCS. It is looking at developing networks where clusters of power stations or other heavy industry adopting CCS use the same pipeline infrastructure. This would be much more practical and economic than the wasteful duplication of each building its own separate pipeline.

1. Instead of being released into the atmosphere, carbon dioxide is captured at power stations and heavy industry and is compressed.
2. The compressed carbon dioxide is pumped through a network of pipelines, some new and some formerly used for natural gas, to a suitable well previously used for gas extraction.
3. The carbon dioxide is pumped through the well into porous rock which previously held gas deep beneath the sea bed.
4. The carbon dioxide filters into the porous sandstone reservoir, filling the tiny spaces which once held natural gas. It is trapped from escaping by the layers of solid rock above, just as the gas was trapped for millions of years.

• More Key Facts about Carbon Capture and Storage.