Sunday 10 May 2009

You just can’t clean coal, warn activists


The Sunday Times
May 10, 2009

Tricia Holly Davis

THE government’s latest plans to turn coal into a “clean” fuel are coming under increasing attack by climate-change activists and scientists.
They say the technology to be used (see below) would miss the majority of new coal-plant emissions – if it works at all. Carbon Capture and Storage (CCS) has been proven only on small power stations that generate about 30MW of electricity, but new coal plants would produce 50 times that power. CCS-fitted plants also require more coal to operate, using up 25% to 40% of the total power generated to run the carbon capture equipment.
Even the government’s former chief scientific adviser is perplexed by the plan. “The energy needed to run CCS is significant and that of itself is a real problem,” said Sir David King.
The bigger concern, said King, is that most of the emissions from new coal plants could go unabated.

“All new coal plants should be fitted with precombustion technology, where 90% of carbon emissions are captured, if we are to meet our climate-change targets,” said King.
The government wants to experiment with different types of CCS. According to a letter from Downing Street obtained by The Sunday Times, of the four new coal stations planned, at least one would be fitted with the precombustion system. Eon has drawn up plans for a 400MW precombustion plant in Lincolnshire, though there are a number of other candidates.
Another station would be fitted for postcombustion, where the carbon is removed after the coal is burnt, capturing only 20% to 25% of emissions. The other two plants are undecided.
A Downing Street official said testing various technologies is the best way of working out the costs of CCS – currently estimated to add £800m to each new coal station. “Britain can lead the global CCS market, but we need to make it cost-effective. If we demonstrate different technologies then we have a wider range of expertise to sell to the world.”
Under the government’s proposal, no new coal-fired power station will be licensed unless at least 400MW of gross capacity is fitted with CCS. However, this represents only about 25% of the total generating capacity of proposed coal plants.
The government said the entire capacity of the plant must convert to CCS within five years of the technology being technically and commercially proven. But nobody knows how long it will take to prove CCS works on a large scale. The government is banking on it working by 2025, but it could take longer.
There is also the question of how the government will enforce its plan. It is unlikely to pull the plug if a power company argues CCS is not a commercially viable option and delays installing it.
Friends of the Earth estimates the government’s experiment could add about 4,000MW of dirty energy to the UK’s electricity mix. This would contribute double the emissions of equivalent-sized gas power stations. This is on top of the pollution caused by existing coal plants.