A NEW method for storing carbon dioxide could help to unlock the North Sea's vast storage potential, researchers claim.

New industry-backed research suggests that injecting carbon dioxide into rocks at more than one point simultaneously could offer the key to the storage of greater volumes of the greenhouse gas.

The CO2MultiStore study, a research partnership which includes the Scottish Government and Scottish Enterprise, reached their findings after a study of rocks beneath the North Sea, which has been used by scientists and prospective site operators to predict the performance of a potential CO2 storage.

They estimated the Captain Sandstone, an extensive sandstone formation which lies more than a mile beneath the Moray Firth, could securely store at least 360 million tonnes of CO2 in just one sixth of its area.

The figure, which is estimated to equal the amount of CO2 emitted by Scotland's energy supply sector over 23 years, is based on carbon dioxide being injected at a rate of between six and 12 million tonnes per year over 35 years.

The process of storing CO2 captured from power plants and industrial facilities in deep geological formations, called carbon capture and storage (CCS) – is considered a major technological solution for meeting climate change aims.

And it is thought that the study’s conclusions will help build confidence among regulators and investors in the secure containment of CO2 within ‘multiple user’ storage formations.

While CCS technology is considered to be a crucial technology in meeting climate change targets, it has so far proved prohibitively expensive. The UK is estimated to have the potential to store around 78 billion tonnes of CO2, while the government predicts the CCS industry could be worth £6.5bn a year by the early 2020s.

The government is currently considering bids from Peterhead's gas-fired power station in Aberdeenshire and Drax coal-fired power station in North Yorkshire in a £1bn competition to encourage the development of CCS technology. A decision is not expected until early next year.

Dr Maxine Akhurst, from the British Geological Survey, which led the CO2MultiStore project, said: "Our study is one of the keys that will unlock the potential CO2 storage capacity underlying the North Sea and release this immense storage resource.

"Our results show that by using more than one injection site in a single sandstone, operators can store greater volumes of CO2 compared to using a single injection site, so increasing Europe's capacity to reduce greenhouse gas emissions."

But WWF Scotland, the environmental group, warned against relying on the technology to achieve climate change targets.

Its director Lang Banks said: "While a better understanding of the techniques that might one day be used to store carbon is important, there's no guarantee that the technology will be commercialised and rolled out in time, meaning Scotland's climate targets could easily be missed.

"Although we'd still like to see CCS tested at Peterhead, given how slowly this technology is progressing, it would make sense for ministers to also explore alternative paths to cutting carbon.

"Independent research has shown not only is a renewable, fossil-fuel free electricity system perfectly feasible in Scotland by 2030, it's actually a safer bet."

Scottish Energy Minister Fergus Ewing said: "This research confirms how the huge CO2 storage resource potential beneath the North Sea can be optimised, which, combined with the infrastructure already in place, again reinforces the huge opportunity for Scotland around CCS.

“CCS can contribute significantly to the diversity and security of electricity supply, and also has a unique role to play in providing a continuing supply of flexible clean fossil fuel capacity that is able to respond to demand in the way that other low-carbon technologies cannot.”