Carbon Capture and Storage (CCS) is a method of capturing carbon dioxide emissions from fossil fuel power plants and storing them so that they are not released into the atmosphere. The carbon dioxide is compressed at pressures of around 100 atmospheres until it turns into a dense liquid. It is then injected into porous rock layers several kilometers underground where it is retained by overlying layers of impermeable rocks for tens of thousands of years.
It is said that CCS applied to a modern conventional power plant could reduce emissions by up to 90%. The importance of CCS as one of the tools against global warming is highlighted in a report by the International Energy Agency, which found that CCS could contribute to a 19% reduction in global CO2 emissions by 2050, and that fighting climate change could cost over 70% more without CCS. It is popular opinion that fossil fuel and nuclear power is needed to balance the intermittency and cost of renewable sources but also that we need to reduce CO2 emissions drastically, so surely investment in this technology is a no-brainer?
In its 2010 spending review the UK Government announced that it was investing £1 billion to support the first UK CCS demonstration project. Whilst nothing has yet been built there are 4 projects in the pipeline. These projects will act as the proving ground for the technology and they will be watched closely because one of the major shortfalls of CCS is that it isn’t proven and there are many doubts about it’s viability. Prof Stuart Haszeldine from Edinburgh University says “the UK has a huge amount of potential storage, amounting to about 700 years worth of emissions, but that is as yet unproven; and no commercial company is going to go ahead and build a CCS facility costing maybe £1bn if they don’t know they’ll be able to inject CO2 for 30 years into that site.”
There are unfortunately several other problems with the technology. Costs of CCS are currently estimated between $50 and $100 a tonne of CO2. The value placed on CO2 at present is far below that range, meaning that for CCS to flourish the carbon price needs to rise or CCS costs need to fall: in reality, both have to happen. Also, CCS requires a lot of energy to implement and run- up to 40 percent of a power station’s capacity- so the power advantage that fossil fuels have over renewables will be reduced. Another concern is the environmental risk. What happens if the carbon dioxide leads out underground? Or in the open sea?
At first glance it seems that CCS is the perfect solution to fossil fuels big foe carbon dioxide but in reality there are many complexities. The costs, risks and uncertainties challenge investment in the technology. Money used to invest in CCS could instead be used to promote clean, renewable energy growth, after all, CCS will only ever be a temporary measure whereas the infrastructure for wind, solar and tidal energy can remain for many years to come.