Cracks in carbon capture schemes

Courier Mail
Friday 10/12/2010 Page: 80

There is growing opposition in Australia and overseas to projects proposing to store carbon underground

FOR years it has been billed as a way for the world to keep generating electricity from fossil fuels without burning up the planet. But in contrast to solar power, which has been fondly embraced even in people's own homes, plans to use carbon capture and storage (CCS) technology to slash greenhouse gas emissions from coal and gas-fired power stations have proven controversial. So much so that some projects have now been ditched.

Scientists say developed nations' emissions need to start falling by 2015 and be almost zero in about 30 years to have a strong chance of holding global warming to 2C the target most countries, including Australia, have adopted. Emissions from coal-fired power stations are the major contributor to climate change and gas-fired generators are also large emitters. CCS is intended to catch 65% to 90% of plant emissions, turn the CO₂ into liquid and pump it underground to be stored forever, with no leakage.

Its complexity and cost mean it has been in experimental mode for years and no power station with capture and storage at major scale exists anywhere. CCS needs to get a move on given the deadline looming for emission cuts and because it faces a challenge from emission-free solar and wind power stations that are now arriving in force in the global energy market. A 1000-MW solar power station starts construction this month in the US and an 845-MW wind farm has also been approved there.

By contrast, in Germany, which is home to the world's most advanced carbon-capture pilot plants, utilities RWE and Vattenfall had to shelve plans to store carbon from two leading projects due to community concerns, including fears over water pollution. And protests by residents and the local council last month caused the Dutch Government to cancel a plan by Shell to store carbon underground at Barendrecht. "They're saying what if the CO₂ has heavy metals and gets into groundwater, even in a thousand year's time.

And saying, we know it's going to be stored a kilometre underground, but what if the strata has a crack and the stuff can leak (upward) until its into our groundwater", said Robin Batterham, Australia's former chief scientist who was recently in Germany to advise on CCS. Similar concerns are surfacing here, where developers are now working to pin down sites for CCS plants and storage.

The Queensland Government has released 13 land areas for industry to explore for storage in the Blackall-Tambo area near Emerald, the Roma-Wandoan area and the Chin area, covering the Surat, Bowen, Galilee and Adavale basins. Queensland farmers' organisation AgForce says there are concerns that planned underground carbon storage in Queensland's Surat Basin and other basins may harm the Great Artesian Basin or the Murray-Darling Basin.

"The Surat Basin is over the GAB and is interrelated with the Murray-Darling Basin, and if we start having significant GAB impacts, then will the last one on the Darling Downs please turn the lights off. It's as simple as that", AgForce spokesman Drew Wagner said. "The reality is we do not know what impacts (CCS) may have on underground water. We don't know what impacts it may have on inter-aquifer relationships and we also may find it's going to have impacts in terms of tying up prime agricultural land".

NSW Farmers' Association president Charles Armstrong last week said CCS could leave the public with a dangerous, expensive legacy. Swiss miner Xstrata's unit CTSCo has been shortlisted as a preferred tenderer for carbon storage in Queensland. CTSCo would look to transport and pump into the Surat Basin up to 2.5 million metric tons of liquid CO₂ a year from a Wandoan coal-fired power plant that would be built by Stanwell Corporation and General Electric, with government funding.

CTSCo will start its community engagement process, or detailed talks with local communities, once it receives permit conditions likely next month or in February and has decided on its specific preferred sites. A 2009 study for the Queensland Government said the Surat Basin was a potentially prime target for high volume carbon storage but said more study was needed into links between water bodies and that well field location "is critical to mitigation of detrimental contamination effects".

"The cost of remediation strategies for damage to existing infrastructure resulting from CO₂ contamination could be prohibitive. Environmental impacts could be severe but remain speculative and cannot be quantified with currently available information", the study said. But it said several factors "contribute to a high level of confidence in an adequate safety margin".

CTSCo project director Alan du Mee said the Wandoan project would store CO₂ up to 2km underground in sites that are generally isolated from potable water. "The first stage is drilling holes to test rock properties and water quality. Later comes CO₂ testing, pumping it down and seeing what happens.

In each of those stages you're monitoring if there is any interaction with water supplies", Mr du Mee said. "(It's a) development project so that we all understand what does this take, what does it do, is it going to work, can we do something with CO₂. It's all 'gently, gently'. In the end, it's the communities and public at large that are going to decide whether this thing's going anywhere."