Underground gas caverns approved

14 gas chambers will be constructed a mile and a half down

A £500m project to create 14 gas storage caverns 1.5 miles (2.4km) under the Dorset coast has been given the go-ahead.

The natural gas chambers will house one billion cubic metres (1,000 billion litres) of gas - 1% of the UK's total gas demand - underneath Portland port.

On Friday, Dorset County Council agreed planning for the scheme and infrastructure to transport the gas.

Construction at the Upper Osprey former naval base will start this summer.

The caverns are due to be ready for the winter of 2015.

The project is possible due to thick Triassic rock salt under Portland.

The 220 million-year-old rock can be dissolved safely using seawater to create impermeable caverns to store natural gas.

Jim Knight, MP for south Dorset, said: "The gas storage project is in the national interest and it brings substantial benefits to people in south Dorset."

Permanent jobs

The project is expected to bring more than £2m investment for local projects over the next two years as well as creating 25 permanent jobs.

Andrew Hindle, chief executive of Portland Gas, said: "The decision is good news for south Dorset and for the nation as a whole."

"In national terms, the need for gas storage is urgent and Portland will be very important in safeguarding our energy security in the future."

The Department for Business, Enterprise and Regulatory Reform (BERR) is expected to announce its decision on a planning application for a pipeline to take the gas to the National Grid.