Coolimba Power will provide a competitive energy solution for many consumers in the SWIS, and will be designed and operated in accordance with very high standards of environmental performance. It will represent best practice in terms of water use and sulphur emissions, and will be an Australian flagship project in terms of its ability to limit its future emissions of carbon dioxide. The Coolimba Power Station will become a low emissons power station, using carbon capture and storage technology.
The location of the power station will help to reduce the transmission network losses that currently exist transporting electricity from the Collie Basin and the metropolitan area into the Mid West region. Having a base load power station in the region will significantly reduce these losses and improve the reliability of supply in the region.
The location will also bring other environmental advantages. With limited access to seawater for cooling of the plant, the project will be built from the outset as air cooled, which will minimise the impact on ground water supplies. If the power station was built with a conventional cooling system, it would consume about seven to nine gigalitres per annum of water, traditionally seen as a plume from the station's cooling towers. The Coolimba Power Station will use air cooled condensers, requiring large fans to force air through radiators to condense the exhaust steam to water. Air cooling comes at additional cost and reduces the efficiency of the power station, but importantly, it will minimise the impact of the power station on the existing groundwater in the region.
The power station will still require access to a limited quantity of water for process water, but this should be sourced principally from the dewatering of the adjacent coal mine.
The Coolimba Power Station will be fuelled by coal mined from an adjacent coal deposit. This deposit contains sufficient black coal to supply the power station for its 30 year life, although the quality of the coal is not high by Australian standards. In particular, the coal contains above average amounts of ash and sulphur. Most Australian coals do not contain levels of sulphur that warrant its capture after combustion. However, the coal at Eneabba may require the capture of sulphur in the flue gas, depending upon the technology employed in the boiler. If required, the Coolimba Project will be equipped with flue gas de-sulphurisation (FGD) to capture the sulphur as gypsum before it is emitted to atmosphere. This will increase the water consumption of the project, and will require the use of limestone in reasonable quantities in the FGD plant.
The operation of the Coolimba Power Project is not expected to have an adverse impact on the community. The closest town is more than 20km from the Project site, and prevailing winds will favour non-populated areas to the north east of the Project area.
The coal will be mined using a dip-cut method. This mining method will allow virtually all of the mined area to be back filled to its original contours and returned to previous land use. In addition, Aviva proposes that all of the ash produced by the combustion of the coal will be returned to the mine for disposal, thus eliminating the unsightly ash ponds that surround many existing power stations.
Environmental approval studies for Coolimba Power have already commenced, including ground water monitoring and flora and fauna surveys, and results are expected to be finalised in 2008.
