There is no shortage of research questioning the credibility of carbon capture and storage as an effective tool in the fight against climate change, but a new report out of America's Stanford University goes one step further, arguing that adding CCS to coal plants could be worse than having none at all.
The research, by Professor Mark Jacobson, compares the data from a coal plant with carbon capture and use (CCU) and a plant that removes carbon from the air directly (synthetic direct air carbon capture and use, or SDACCU), both of which use gas to power the carbon capture technology.
It finds that both of the plants either increase or hold constant their contributions to air pollution and reduce little more than 10 per cent of carbon emissions, before even considering sequestration or fugitive emissions.
And then there are the other drawbacks of the technology, including the high social cost of unfettered pollution and the high financial cost of installing the equipment.
"All sorts of scenarios have been developed under the assumption that carbon capture actually reduces substantial amounts of carbon," said Jacobson.
"However, this research finds that it reduces only a small fraction of carbon emissions, and it usually increases air pollution.
"Even if you have 100 percent capture from the capture equipment, it is still worse, from a social cost perspective, than replacing a coal or gas plant with a wind farm because carbon capture never reduces air pollution and always has a capture equipment cost. "
On the other hand, he adds, "wind replacing fossil fuels always reduces air pollution and never has a capture equipment cost."
The report is not alone in slamming the door on CCS as an effective carbon "escape route" for countries like Australia that wish to keep their coal fires burning. There have been many.
One, published late last year from consultancy Lazard, estimated that energy from an integrated gasification combined-cycle (IGCC) plant with carbon capture would cost $ US231 per megawatt hour (MWh), far more expensive than both solar and wind generation.
But the data from Jacobson is damning about the ability of the technology to do its “one job” of preventing carbon from getting into the atmosphere in the first place. According to the data, the carbon captured at the two plants amounts to around 10-11 per cent of overall emissions produced, averaged over 20 years.
This is in stark contrast to some of the more optimistic and common estimates of carbon capture technologies, the report notes – including those bandied about by some of Australia’s top politicians – of around 85-90 per cent of emissions.
The research also looks at the social cost of carbon capture – including air pollution, potential health problems, economic costs and overall contributions to climate change – and finds it hardly an improvement at all on a coal plant without the technology.
Even when the capture equipment is powered by renewable electricity, Jacobson concluded that it is always better to use the renewable electricity instead to replace coal or natural gas electricity or to do nothing, from a social cost perspective.
"The low net capture rates are due to uncaptured combustion emissions from natural gas used to power the equipment, uncaptured upstream emissions, and, in the case of CCU, uncaptured coal combustion emissions," the report says.
"Moreover, the CCU and SDACCU plants both increase air pollution and total social costs relative to no capture."