Cutting carbon emissions easier said than done

Australian
Thursday 15/3/2007 Page: 10

Switching to clean coal is an enormous commitment that neither the Government nor the Opposition should underestimate

THE Howard Government this week announced its largest grant yet for projects to reduce greenhouse gas emissions and save the planet: $100 million for a clean coal plant in Victoria's Latrobe Valley.

There's one in the eye for those who say the Government is too infested with climate change sceptics to take the issue seriously. Even the Opposition welcomed the announcement, while berating the Government for dragging the chain. We're all greenhouse warriors in an election year.

The money will go into a demonstration project to build a 400 megawatt power generation plant at the Loy Yang coalmine. Industry Minister Ian Macfarlane and Environment Minister Malcolm Turnbull said it would produce power more efficiently, at lower cost, with 30 per cent lower carbon dioxide emissions than conventional brown coal.

But let's get this into perspective. The new 400MW plant compares with the more than 30,000MW of capacity in coal-fired power stations in Australia. brown coal is the dirtiest coal, producing as much as twice the carbon dioxide of black coal. The aim of the demonstration project is to dry the brown coal to make it cleaner, but that would still leave it dirtier than black coal.

Moreover, generating electricity from black coal is itself a very dirty process when it comes to greenhouse gases. The grant does not cover developing the process to capture carbon dioxide from coal-fired plants, let alone transporting and storing it.

The Government has funded some projects for this purpose: $60 million for commercial scale demonstration of the capture and storage of carbon dioxide at Barrow Island in Western Australia and $50 million for a demonstration project of carbon capture on existing power stations. But these are very small and preliminary steps down the road of taking carbon dioxide out of the atmosphere. From little things, big things grow: and they will need to, given the sheer scale of the challenge. The Barrow Island project aims to take up to 3.2 million tonnes of carbon dioxide out of the atmosphere a year.

That sounds impressive until we learn the staggering overall quantities involved. Just one typical 1000MW coal-fired power station produces five to six million tonnes of carbon dioxide a year. That adds up to 150 to 180 million tonnes a year from burning coal in Australia, a figure that is continuing to grow and which in turn is about one-third of total greenhouse gas emissions.

Clean coal trips off the tongue easily enough, but what is involved in capturing hundreds of millions of tonnes of carbon dioxide? Politicians anxious to defend the coal industry make it sound easy but seldom go into the detail. Labor's resources and energy spokesman Chris Evans says most of the technology for the capture and storage of carbon dioxide "has been proven". Up to a point.

A 2005 paper by the International Energy Agency and the Organisation for Economic Co-operation and Development says: "Proven cost effective means for removing and sequestering [that is, burying] most of the CO2 emissions from coal-based power plants do not currently exist." But it adds that the prospects over the next two decades are promising.

As for Australia, the development of technologies "would require a significantly greater level of commitment on the part of industry and government than in the past". Although this does not take into account the projects announced since, it remains a valid point.

The widely used term of carbon capture and storage is shorthand for a very complex process, even without considering the sheer volumes involved. First the carbon dioxide has to be captured in the power generation process. There are three main methods being worked on and at least two of them require large amounts of energy in themselves.

Britain's Department of Trade and Industry argues that one of them, post-combustion capture, involves a well-established technology but that the largest operating unit, in California, captures less than 10 per cent of the gas put out by a small, 500MW coal-fired power station.

After the carbon dioxide has been separated, it has to be compressed to a liquid or dense gas form another energy intensive process that makes it suitable for transport through pipelines. Moving the carbon dioxide is proven technology, with the US using pipelines to take it to wells to help extract oil.

But it also is not cheap. Existing pipelines such as those used for natural gas are not suitable, meaning dedicated pipelines have to be built at a cost which a University of California study estimates at $US1 million ($1.3 million) per kilometre to move large volumes.

Huge amounts of storage are required and in theory they are available, including in Australia, in the form of depleted oil and gas fields, coal seams that cannot be mined and saline aquifers. But they often are a long way from power plants and, as the study by the IAE and OECD says,"considerable research and development effort is still required to clarify and confirm these options". Once stored, the carbon dioxide has to be monitored to ensure against leakage.

Perhaps all these hurdles can be overcome in time. They require sticks and carrots in the term of a carbon tax or a trading scheme with a cap on emissions. The Government is moving gradually towards the second option, which also is the one the Opposition supports.

The inevitable result of the investment required to clean up coal is that the cost of producing electricity increase greatly. The CSIRO estimates it will double, which would make other options, such as wind, solar and nuclear more competitive.

If we take the Stern report on the economics of climate change literally, we cannot wait 20 years to clean up coal, an argument that has led the Greens to propose phasing out the coal industry, including exports. With coal our biggest export earner no major party leader is going to agree to that. It would be a futile gesture, in any case, in the absence of an international agreement to prevent importing countries simply switching to other sources of supply.

But we should not pretend that the path to clean coal will be easy, or that we can continue living forever off our bounty of cheap coal.

Labor has committed to reducing greenhouse gases by 60 per cent by 2050 without saying how it will get there beyond an unspecified increase in the Mandatory Renewable Energy Target. Like the Government, it is in denial.