Two Norwegian carbon capture projects – used by the Scottish Government to justify its support of the controversial technology – reportedly faced problems which could have caused carbon dioxide (CO2) to leak.
The Scottish Government is a big financial backer of carbon capture and storage (CCS) and claims Scotland has the potential to be the “centre of a European hub” for CO2 storage.
CCS involves catching CO2 from the production and burning of fossil fuels, or other dirty industrial processes, and storing them under the ground or the sea. As long as it stays in place, this stops the CO2 entering the atmosphere and contributing to the climate crisis.
Scottish ministers have pointed to the apparent success of CCS at the Sleipner and Snøhvit gas fields in Norway as proof that its reliance on the technology to help Scotland meet its climate targets is “credible”.
But recent analysis of expert research on the two projects by the global think tank, the Institute for Energy Economics and Financial Analysis (IEEFA), found that both projects had seen unexpected storage behaviour “that could have led to leakage”.
Rather than being lauded as “pioneers” of CCS as they have been by the Scottish Government, Sleipner and Snohvit’s issues should actually “call into question the long-term technical and financial viability” of storing carbon underground, the IEEFA report argues.
Environmental campaigners said the research showed the Scottish and UK governments had “fallen for industry greenwash” on CCS. Because there are no large-scale CCS projects operating in the UK, attempts to store carbon off Scotland’s coast would be “proceeding by trial and error”, one argued.
The Scottish Government pointed out that its independent advisers had described CCS as “a necessity, not an option” to achieve net zero. Its energy secretary, Neil Gray, said studies found “a ‘very high level’ of confidence in the long-term security of CO2 contained in typical UK CCS storage complexes”.
The government believes that five million tonnes of CO2 could be stored under the North Sea as soon as 2030. It estimates 46 billion tonnes of CO2 storage capacity exists under Scottish waters.
Sleipner and Snøhvit have only stored a combined 22 million tonnes of CO2 in total so far, having first come online in 1996 and 2008, respectively. Both projects capture and store CO2 from the production of natural gas.
Despite their relatively small size – and the fact their storage locations were in areas studied extensively – the IEEFA study argues that “CO2 had not behaved as geologists initially expected at either project”.
At Sleipner in the Norwegian North Sea, CO2 moved upwards from the original storage site into a previously unknown geological layer three years into operations. “Had this unknown layer not been fortunate enough to be geologically bounded, stored CO2 might have escaped,” the report claims.
Meanwhile, at Snøhvit in the Barents Sea pressure in the storage site “rose rapidly to alarming levels” just a year and a half after CO2 was first injected. The storage capacity there was far lower than predicted by engineers, a problem which required expensive investment to fix.
On Monday, the prime minister, Rishi Sunak, announced that Scotland’s first CCS facility, the Acorn Project at St Fergus in Aberdeenshire, will receive a share of £20bn of funding from the UK Government. The Scottish Government had already pledged £80m of support for Acorn.
The announcement came alongside renewed commitments by Westminster to allow new oil and gas exploration in UK waters. Opponents of CCS claim it distracts from the need to invest in renewables and is being pushed by the fossil fuel industry so that it can continue drilling for oil and gas.
Acorn — which lists fossil fuel giants Shell and Harbour Energy as partners — will transport CO2 and store it a mile and a half under the North Sea.
Initially this captured CO2 is expected to come from a collection of industrial sites and power plants in the Central Belt and on the north-east coast, known collectively as the ‘Scottish Cluster’.
Acorn could also be used in future to store CO2 captured elsewhere in the UK or internationally and transported to Scotland by ship.
The author of the IEEFA report, Grant Hauber, told The Ferret that “nowhere in the world has CO2 storage been attempted at such a scale as that proposed” in Scottish and wider UK waters.
“Once CO2 is injected into the ground, it is effectively on its own. All engineers can do is to regulate how much volume of CO2 is injected at a certain pressure. They cannot fix leaks in the rock. They cannot dictate where the CO2 will move. They cannot stop it from leaking once it starts.
“If projects meant to securely and permanently store CO2 begin leaking, whether a year into operations or twenty years hence, what does that do to Scotland’s decarbonisation strategy?”
Both the Scottish and UK Governments have fallen for industry greenwash.
Alex Lee, Friends of the Earth Scotland
Erik Dalhuijsen – a petroleum engineer who has worked on CCS for over a decade – warned a Scottish Government committee in 2021 that rather than a poster child for CCS, Sleipner might be its “most visible failure”.
Dalhuijsen, who also co-founded the group Aberdeen Climate Action, told The Ferret there are additional “huge risks” associated with potential leakage from “old oil and gas wells”, including in the UK context.
“The way these were left behind was never intended to hold CO2 underground, and many can no longer be found, let alone repaired,” Dalhuijsen claimed.
Dalhuijsen added that CO2 needs to stay underground for “roughly 10,000 years” before it hardens and stays there permanently. “The normal industry understanding of risk is completely inadequate for this duration, and risks and impacts of leakage are greatly under-estimated,” he claimed.
Alex Lee, climate campaigner at Friends of the Earth Scotland, agreed. Lee said: “This research raises real red flags about a project that Scottish Ministers have hailed as a pioneer, and used to justify their over-reliance on CCS technology to meet climate goals.”
“The fact is there is no large scale carbon capture and storage scheme working anywhere in the UK and so the industry will be proceeding by trial and error.
“Both the Scottish and UK Governments have fallen for industry greenwash rather than face the reality that the only solution to the climate crisis is a fast and fair phase out of oil and gas.”
The Scottish Government energy secretary, Neil Gray, said research by Marine Scotland had found the likelihood of leaks from the CCS industry off the Scottish coast to be “low and produce minimal environmental impact”.
Gray added: “A further study commissioned by the UK Government found a ‘very high level’ of confidence in the long-term security of CO2 contained in typical UK CCS storage complexes.
“The independent Climate Change Committee has described CCS as a ‘necessity, not an option’ to achieve net zero emissions.”
A spokesperson for the Acorn Project said: “Acorn’s stores will meet the directives and guidelines set out by the North Sea Transition Authority. Comprehensive containment risk assessment processes, regular monitoring and plans for appropriate mitigation and corrective measures will all be in place.
“We are completely confident that the mitigation and safety measures we will have in place mean the potential for CO2 to escape our stores 2.5km below the sea bed is not significant, as required by the NSTA.”
Equinor – the Norwegian-state energy firm which operates the Sleipner and Snøhvit projects – was asked to comment.
Main image: iStock/Coatesy
This story was updated at 09:50 on 7 August 2023 to correct a comment by Erik Dalhuijsen about the potential for CO2 to leak through old oil and gas wells.
It was updated again at 14:32 on 16th August 2023 to reflect an incorrect paraphrasing of Erik Dalhuijsen’s comments, which did not suggest there was a specific risk of CO2 leakage at the Acorn project.
This Ferret story was also published with the Herald. Our partnerships with other media help us reach new audiences and become more sustainable as a media co-op. Join us to read all our stories and tell us what we should investigate next.
