Will carbon capture and storage work?

Industrial pipework
Carbon capture sounds like a fantastical idea: dig up fossil fuels, burn them, then return the captured CO2 underground. But the hurdles that stand in its way are formidable

Things are hotting up for the carbon capture and storage industry.

Across the world, there are some 200 test projects are underway to see whether carbon capture and storage is viable, both technically and financially. Most are still at the planning stage and only eight are up and running. None is operating at anything like the scale needed to make a serious dent in our CO2 emissions, yet they are cited by supporters as proof that the basic concept does work.  

At the Sleipner gas field in the North Sea, Norwegian company Statoil is removing excess CO2 from the gas and storing it underground. A similar project is up and running at In Salah in Algeria, where Statoil has joined up with BP and Algerian firm Sonatrach. Captured CO2 is also being piped 330km from a coal power station in Beulah, North Dakota, to the Weyburn oil field in Saskatchewan, Canada, where it is pumped underground to help extract oil, a process known as enhanced oil recovery.

An upbeat industry

These examples were widely quoted at a conference on carbon capture and storage held by the Institution of Mechanical Engineers in London this autumn. The mood was ebullient: speaker after speaker called for urgent investment to build bigger demonstration plants before a global roll-out sometime in the 2020s. Tony Grayling, head of carbon capture and sustainable development at the Environment Agency, predicted that 'carbon capture and storage will play an important, if not essential, role in meeting our de-carbonisation targets.'

Grayling pointed out that no-one has yet built a full-scale demonstration project, with most existing tests applied to power outputs of just 30 or 40 megawatts. But in November the UK government confirmed plans to provide funds for up to four carbon capture and storage demonstration projects of 300 megawatts or more.

These will be funded at least partly by a levy on electricity bills, enshrined in the energy bill which has yet to be passed in Parliament. The Government has proposed that the Environment Agency will assess whether carbon capture is technically and financially viable by around 2020. 'This is an enormously ambitious timetable,' said Grayling. 'We are sceptical about whether there will be enough demonstration projects by then to make a proper assessment.'

Environmentalists split

Carbon capture has divided the UK green movement, with Friends of the Earth an enthusiastic supporter, while Greenpeace and the Green Party are lukewarm or downright hostile. In May 2008 Greenpeace branded carbon capture 'a scam'. Its report, 'False Hope', argued that carbon capture cannot be made ready in time to avert dangerous climate change, that storage may be unsafe and that the extra energy required to capture, transport and bury C02, would accelerate the exploitation of natural resources. 'False Hope' also argued that the cost of carbon capture would inflate electricity bills by anything from 21 per cent to 91 per cent.

Where could all the carbon go?
Prospective areas in sedimentary basins where suitable saline formations, oil or gas fields, or coal beds may be found Source: IPCC, 'Carbon Capture and Storage', 2005

Greenpeace appears to have softened its attitude since then. 'We are not ideologically opposed to it, but it shouldn't be seen as a silver bullet,' says Jim Footner, senior energy campaigner at Greenpeace UK. Footner is concerned that the prospect of carbon capture may be used to justify more coal plants, so emissions would carry on rising even if the bulk were captured. He also fears it may divert money and political will away from renewable energy and energy efficiency, which Greenpeace sees as more pressing priorities.

Similarly, Green Party leader Caroline Lucas says that while the party is 'not completely against the idea' of carbon capture and storage, it 'should certainly not divert attention and resources from energy efficiency and renewable power'. Investment in these areas would create many times more jobs than carbon capture and storage, Lucas adds.

Enormous quantities

In his latest book, 'Our choice: a plan to solve the climate crisis', climate change campaigner Al Gore argues that because of the huge energy cost of capturing and storing CO2, coal-fired power stations would have to burn 25-40 per cent more coal to produce the same amount of electricity, leading to significant environmental damage.

Gore also believes the sheer volume of CO2 capture that would be needed to make a difference 'strains credulity'. If all the CO2 emitted by US coal power stations were captured and converted into liquid form, the volume would be equivalent to 30 million barrels per day, which is three times the daily volume of US oil imports. Gore adds that finding suitable geological sites will be a mammoth undertaking. Former oil and gas fields will only hold a fraction of the world's CO2 output and the longer-term assumption is that most of it would be stored in saline aquifers 1 to 4km underground. Complex and time-consuming research is needed to identify which sites would be suitable.

However, Gore concludes that the transportation and burial of CO2 is likely to be safe, citing separate studies by the Massachusetts Institute of Technology and the IPCC. While noting that carbon capture and storage 'is probably impractical for many years to come', he believes that large-scale demonstration projects should be built 'to determine how realistic this idea might be'.

Taming King Coal

But despite the technological unknowns, the argument for at least experimenting with carbon capture is compelling. The Intergovernmental Panel on Climate Change has said carbon capture and storage could account for between 15 per cent and 55 per cent of the global economic effort to cut CO2 emissions by the end of this century. On top of this, coal fulfils 25 per cent of the world's total energy demand, while renewables provide just 0.4 per cent, according to 'The Future of Coal', a 2007 report by the Massachusetts Institute of Technology. It argues that 'coal use will increase because it is cheap and abundant'. The Institute notes that China is currently building two coal power stations a week, and the International Energy Agency predicts that the global demand for energy will rise 45 per cent by 2030 as developing nations industrialise. Lord Nicholas Stern, author of the 'Stern Review on the Economics of Climate Change', argues in his book A Blueprint for a Safer Planet, that 'China, India, Poland and others are likely to rely strongly on coal, perhaps 70-80 per cent or more, for the next few decades, largely because it is cheap, power stations can be built rapidly, and it is available internally and is thus secure.'

What could be captured?
Diagram of possible CCS systems, showing capture from industry, oil refineries, and electricity generation Source: IPCC, 'Carbon Capture and Storage', 2005

Stern calls for an immediate investment in 30, large-scale carbon capture demonstration projects around the world over the next 10 years, to test different geologies and types of coal: 'We must learn quickly whether it will succeed or fail,' he says. 'Even though it may only be a transitory technology between 2020 and 2050 as other technologies are developed, that is a crucial period.'

No choice

Jon Gibbins, professor of power plant engineering and carbon capture at the University of Edinburgh, believes the UK has no choice but to use carbon capture if we are to achieve an 80 per cent reduction in carbon emissions by 2050. 'We can't change the way our energy system works fast enough to do it without carbon capture and storage,' he says. He is convinced the technology can be made to work: 'There is no question of that, the issue is money and time.' Although carbon capture is likely to be expensive, Gibbins argues that it is unlikely to be any more expensive than electricity from offshore wind.

Figures given by electricity generator EON to a parliamentary select committee in 2008 suggest that electricity generated using coal with carbon capture would cost £68 per megawatt hour, compared to £42 without, while electricity from onshore wind farms would cost £75 per megawatt hour and, from offshore wind, £107 per megawatt hour. Perhaps, as Gibbins argues, the best way to resolve the cost issue is to build some commercial-scale demonstrations: 'How do you know until you've done it?' he asks.

Neil Crumpton, senior energy specialist at Friends of the Earth in the UK, believes that the case for carbon capture 'gets stronger every day'. Like Stern, Crumpton sees carbon capture as a 'transitional' technology to be used while countries make the switch from fossil fuels to renewables. Pilots such as Sleipner and Weyburn have proved that it can work, he believes, while the additional energy required will fall dramatically as the technology improves, from 25-40 per cent to as little as 15 per cent: 'I've spoken to enough engineers and credible sources to believe that 15 per cent or less is very possible,' he says. This claim is supported by Jonathan Forsyth, technology and engineering manager at BP's Alternative Energy division, who told the engineers' conference this autumn that there would be 'significant progress' over the next decade, with energy losses falling 'from 20-40 per cent to 10-20 per cent'.

Despite being an infant technology, carbon capture is already attracting strong public protest. Efforts by power companies Vattenfall and RWE to bury CO2 in Germany, and by Shell to bury CO2 at Barendrecht near Rotterdam, have been met with fierce opposition and threats of legal challenges. Like Gore, Crumpton argues that CO2 transportation and storage is perfectly safe - explosive gas and petroleum products far more dangerous than CO2 have been held safely underground for millions of years and subsequently transported through pipelines - but public fears will have to be addressed. 'There will have to be lots of public meetings and information given out,' he says.

However crazy and problematic carbon capture may seem, most leading thinkers on climate change seem to agree it is worth pursuing. Whether the public will back it remains an open question.

Mark Jansen is a freelance journalist

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