Underground movement

Scottish national pride had a boost last week. Along with the other ways it leads Britain - the oil industry, fine spirits, shortbread - it seems it could become one of Europe’s centres for carbon capture and storage. The geology of the Scottish sector of the North Sea could store up to 46 billion tonnes of carbon dioxide, according to a recent report from the Scottish Centre for Carbon Storage (part of the British Geological Survey) - more potential storage capacity than Germany, Denmark and the Netherlands combined.

This isn’t so surprising in geological terms, since the North Sea was long ago identified as a likely site for carbon storage, and all the interesting geology is in the Scottish sector. Most of the sites are saline aquifers, porous sandstone structures filled with salt water, which will gradually take injected CO₂into solution and slow down its re-emergence into the atmosphere as part of the carbon cycle enough to remove it from the greenhouse effect equation. At least, that’s the theory.

We’ve got no reason to doubt anything in the SCCS’s report; a look through the Executive Summary shows it’s all sound engineering. The use of CO₂ to enhance oil recovery; onshore hubs to collect CO₂ from power generation and industry before pumping it into a distribution network; interlinking this network to take other countries’ CO₂: it’s all there. But what we have noticed, along with many others, is that while there’s quite a lot of talk about CCS and increasingly detailed studies, there’s not very much action.

More than a year ago, I reported that RWE npowerwas planning to build a 1MW carbon capture unit at Aberthaw near Cardiff, set to come on-stream in 2008. It’s still not been built, let alone commissioned or brought on-stream, and in a recent discussion RWE told The Engineer that it was hoping to finish the plant next year. Even then, they aren’t anticipating storing the CO₂; it’ll probably just be released into the atmosphere, although the company does hope to prove the concept behind its carbon capture technology.

Similar stories abound. Although the government has a target for implementation of commercial CCS by 2015, there seems to be precious little concrete research. All of which seems to confirm what we’ve been told by clean-coal authorities such as Colin Snape of Nottingham University: CCS is a damn sight harder than it looks.

This hasn’t gone unnoticed, and leading environmentalists such as George Monbiot are quick to categorise CCS as ‘greenwash’ - a piece of propaganda trotted out by industry to make it seem more environmentally cautious than it is. While greenwash is undoubtedly around, the indications we have from speaking to academia and industry is that CCS isn’t in that category. It’s hard, but it’s possible, and without it, fossil-fuel-fired power stations cannot be part of our energy producing plans.

It’s enough to make you start looking longingly at some of the more outlandish geoengineering schemes that are featured in our latest issue, such as orbital sunshades or cloud-making machines. But we don’t think the engineers working on the concepts should be discouraged. CCS is something that needs a definitive answer to whether or not it will work, because governments around the world are already factoring it into their energy policies. If it’s a red herring, we need to know sooner rather than later.

We see the SCCS report as an encouraging development. The authors say that surveying needs to begin soon, so that processes can be put into place as soon as the technology becomes available, and they’re undoubtedly right. But we also need to see some answers from the engineers working on the technologies. Can greenhouse gases be shoved out of sight? Or is it this concept that needs to be put away?

Stuart Nathan

Special Projects Editor