King Street Energy
Proposed Gas Storage, King Street, Cheshire
After many years of self-sufficiency, the UK became a net importer of natural gas in 2004 and this trend will continue. The UK is moving from virtual self-sufficiency to being 80-90% reliant on imports by 2020.
In this respect NPL Estates, through its wholly-owned subsidiary King Street Energy (Cheshire) Ltd, is responding to the need for more underground gas storage in the UK by bringing forward the King Street development near Rudheath in Cheshire.
The site was formerly part of the operational Holford brinefield and has an existing planning consent for brining and underground waste disposal. It is proposed to store gas in underground cavities leached in the salt layer some 400m below the surface. The thick salt layer coupled with the overlying marl makes the conditions ideal for gas storage.
NPL is proposing to construct ten cavities, each with a volume of 400,000 cubic metres. It is expected that up to 240 million cubic metres (mcm) of gas will be stored in total, of which up to 160mcm of working gas will be moved in and out during normal operations.
The supporting gas processing facility will be located on the centre of the King Street Site. The existing screening and planned tree and hedge planting will lessen the visual impact and the facility will be engineered to ensure that noise and other emissions will be kept to a minimum.
On the King Street site, there will be a need to bring in drilling and other equipment from time to time but once completed the wellheads will be secured in small compounds and fully screened from the surrounding area. Most of the project space will be returned to long term agricultural use.
In order to speed the development to assist the Government’s timetable objectives, NPL proposes to construct a twin pipeline system between the Mersey Estuary and the King Street site to supply leaching water and to discharge the weak brine. Other gas storage projects in the district take water from the local rivers and pass the brine to process users. However, the rivers have little remaining abstraction capacity and there is no scope for local companies to process more brine for some time to come. The amount of salt which will be discharged into the sea will be minimal compared with the size of the Cheshire/Staffordshire long term reserves.
The pipeline system will include pumping stations at both ends of the line and one set at approximately the half-way point. These facilities will be largely underground. There will be a need for an intermediate storage tank system at the King Street end to provide a buffer between the brining and pipeline operations. All such facilities will have substantial screening to minimise the visual impact.