CARBON capture and storage plants will cut the greenhouse gas emissions of electricity by 20% less than previously assumed.
The claim is made in a new report by Professor Geoff Hammond of Bath University and Dr Craig Jones of Sustain. The article, published in the Energy Policy journal, said that CCS could deliver a 90% reduction in the direct emissions from a power station. However it doesn’t capture the upstream emissions of fuel production, for example, ‘fugitive’ methane emissions from coal mining and gas pipelining, which are 25 times more potent as a GHG than carbon dioxide.
Combined with the fuel penalty of a carbon capture and storage (CCS) installation – between 15-20% – which means an increase in upstream emissions, the report is said to prove that CCS cannot possibly deliver a 90% emissions reduction. In fact, when full life cycle emissions are considered, capture and storage may deliver only a 70% reduction in greenhouse gas emissions (GHG) for coal-fired electricity generation.
Jones, principal associate at resource efficiency company Sustain, said: “This report demonstrably proves the importance of full life cycle emissions. We believe that it’s time for governments to start considering these consumption-based emissions in their policy making.
“For example, with depleting North Sea gas reserves the UK is looking abroad to provide more and more of its fossil fuels. This will require longer transport distances and longer gas pipelines, which in turn gives rise to more fugitive methane emissions and its resulting GHG impact.”
Professor Geoff Hammond, founder director of Bath University’s Institute for Sustainable Energy and the Environment, added: “A 70% reduction in carbon emissions is a significant gain in terms of climate change mitigation. However, if Government departments and agencies presume that CCS can remove 90% of the carbon dioxide in the power station flue gases, they will seriously underestimate the challenge of achieving a decarbonised electricity sector.”
Currently, coal-fired electricity releases 1.09 kg CO2e per kWh of electricity delivered to the UK consumer. This was predicted to fall to 0.31 kg with CCS technology. While gas-fired electricity currently releases 0.47 kg this was also predicted to fall, to 0.08 kg, with CCS.