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| Coming to a farm near you get ready |
Previous posts have highlighted the growing doubts that gas has a role to play as an acceptable transitional fuel on the inevitable journey from fossil fuel to renewable energy. First came peer reviewed published research from Cornell University academics Howarth, Santoro and Ingraffea indicating that life cycle emissions from gas were little if any better than those for coal. Then came a cross post from Climate Progress where Joe Romm reported on damning new research carried out by the US National Center for Atmospheric Research showing that switching from Coal to Gas increases warming for decades and has minimal benefit even in 2100. Now comes an industry commissioned report which contradicts industry claims of the emissions benefits of transitioning to gas and finds that the life-cycle emissions of CSG may be higher than those of black coal used in the most modern coal plants currently being built in China. No surprise then that the industry tried to hush it up. This short report by Giles Parkinson is cross posted from Climate Spectator.
GREEN DEALS: Is CSG cleaner than coal?
A new report commissioned by the peak body of the oil and gas industry suggests that claims coal seam gas exports are up to 70 per cent cleaner than coal exports over their life cycle may not actually be valid. The report by Worley Parsons finds that this is true when compared to coal technologies that are no longer deployed, but it also finds that the life-cycle emissions of CSG may be higher than those of black coal used in the most modern coal plants currently being built in China.
Accounting for the life-cycle emissions of CSG has become a highly contentious point in the debate about the industry, and resistance to it, in particular, from the farming community. The Worley Parsons report, commissioned by the Australian Petroleum Production and Exploration Association, analyses a range of scenarios comparing CSG used in baseload and peaking plants, with a range of coal-fired technologies used in China.
While in the best case scenario, CSG does match the claims of the industry that it can be up to 70 per cent cleaner than coal, particularly when replacing the dirtier subcritical coal technology that the Chinese no longer build, the report notes that gas-fired power is likely to add to capacity in China, rather than compete against coal. “An existing coal-fired plant will not be taken off line and replaced by a gas fired plant," it says. "And, in general, large supercritical and ultra-supercritical plants of up to 1000MW are being built to replace redundant small, inefficient coal plants.”
In practice, then, the best comparisons lie between CSG and the ultra-supercritical coal plants, which has a base-case emissions of 0.78t/Co2e for every MWh produced. Combined-cycle baseload plants with CSG have a base case of 0.55t/Co2e for every MWh, while open cycle peaking plants have a base case of 0.75t/Co2e for every MWh. The graphs below show the ranges – the first is based on different scenarios on all emissions sources, while the second is just on power plant efficiencies, which can vary widely.
The report notes that, under the worst-case scenarios, supercritical and ultra supercritical coal-fired generation on a life-cycle basis would be superior, with CSG/LNG being 2 per cent and 6 per cent more GHG intensive than best-performing coal.
The issue for Australia is that, because of extraction and compressing processes, around 22 per cent of these emissions occur in Australia, with the rest at the point of consumption, whereas only 2 per cent of coal emissions occur in Australia when black coal is exported. Another issue is that Australia is building more open-cycle gas plants than combined cycle, principally because of increases in peak demand, and because of the ongoing uncertainty around carbon prices.
The issue for Australia is that, because of extraction and compressing processes, around 22 per cent of these emissions occur in Australia, with the rest at the point of consumption, whereas only 2 per cent of coal emissions occur in Australia when black coal is exported. Another issue is that Australia is building more open-cycle gas plants than combined cycle, principally because of increases in peak demand, and because of the ongoing uncertainty around carbon prices.
Matthew Wright, the head of Beyond Zero Emissions, which promotes a 100 per cent renewable grid in Australia and is critical of the rollout of gas, says the report makes it clear that gas exported to China will not be replacing coal. “And the examples show that – with the majority of gas-fired plants in Australia being old and outdated open cycle plants and running at lower efficiencies – in most scenarios compared to new-build coal there would be a substantial increase in emissions.”
Update
This report from Giles
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