Carbon capture and storage (CCS) is a technique to remove carbon dioxide from industrial pollution – and especially from power stations – and compress, transport and store it perpetually in secure underground structures such as expired gas and oil fields and other geological formations.
CCS is experimental, unproven technology at the scale required, and if it works the majority of CCS deployment will not occur until the second half of this century, according to the 2005 Intergovernmental Panel on Climate Change special report on carbon dioxide capture and storage.
The Australian Labor government’s CCS initiative, announced on 25 February 2007 when it was in opposition, envisages the technology only “entering the grid” after 2030, a timeline that takes it off the table as a near-term emissions reduction option. If nations in the Asia-Pacific adopted a climate change strategy based on CCS technology, by 2050 emissions would still rise by over 70%.
While a large 2007 study from Massachusetts Institute of Technology expresses confidence that large-scale CCS projects can be operated safely, it worries that “no carbon dioxide storage project that is currently operating has the necessary modeling, monitoring, and verification capability to resolve outstanding technical issues, at scale.”
In other words, it is not possible to know at this stage if the whole technology package will work. Proposed new plants in North America including the much-lauded FutureGen have being scrapped before construction started, largely because they were not cost effective.
As a new and complex technology, CCS, like nuclear energy before it, seems destined to be dogged by cost overruns, unforeseen problems and delays. The biggest concern is that stored emissions could slowly leak over the long term, deferring today’s problem to create a monster greenhouse headache in the future.
CCS is inconsistent with a low-emissions goal because the technology is likely to capture only a portion of greenhouse pollutants, and is energy intensive. If it is possible to capture 80-90% of the carbon dioxide from a coal-fired power station, it would require newly-constructed stations to burn 11-40% more coal to produce the same output; and it would cost more for retrofitted power stations which have lower CCS efficiencies.
The IPCC finds that CCS would double the cost of the electricity where storage sites are distant from power stations, increasing the cost of coal-fired power with CCS to more than that of many renewable energy sources, especially as increasing economies of scale and technology improvements are predicted to halve the cost of renewables generation over the next two decades. Capture expert Greg Duffy told a 2006 Australian parliamentary inquiry that CCS would double the cost of base-load electricity generation, and reduce the output from a power station by about 30%. Dr Lincoln Paterson of the CSIRO told the same enquiry that beyond 100kms the transport costs may become “prohibitively expensive”.
A year earlier, a report from five CSIRO Energy Technology researchers predicted that the cost of electricity from concentrated solar thermal plants would be competitive with coal-fired generation (without CCS) in five to seven years. The report was suppressed by the federal government while hundreds of millions of dollars were allocated for “clean coal” research, and solar thermal initiatives were driven overseas.