“If the government wants to tackle greenhouse emissions, develop the most economical power option and improve the state’s power generation mix, it will choose to build a gas-fired power station,” Jones said.

The Government plans to build another base-load power station to help meet Perth's soaring electricity demand. The station's output for the next 25 years will be bought by state-owned utility Western Power.

Yesterday the state’s Environmental Protection Authority has described combined-cycle gas turbine generation as the best option for the base-load power station, saying a coal-fired station would produce about half the carbon dioxide of a gas-fired station, even with greenhouse gas offsets.

But the environmental watchdog has nonetheless approved three different proposals for a new coal-fired power station to be built near the coal town of Collie in the state’s South-West.

These are competing with a fourth proposal for a from Wambo Power Ventures for a gas-fired power station in Kwinana in Perth’s outer southern fringe, which has also received EPA approval.

The government must now decide which of the tenders it approves.

In January the EPA approved the $250 million Bluewater One coal-fired station in Collie, which earlier this month was granted approval by environment minister Judy Edwards. Construction of Bluewaters One is due to begin this month and it is intended to be onstream in August 2008.

In that case, the EPA had also warned that Bluewaters would generate about twice as much greenhouse gas as a gas-fired model, but the state government approved construction of the station.

The authority has now said each of the proposals for the new coal-fired station would produce nearly one million tonnes more carbon dioxide a year than modern gas-fired plants. In addition, it would produce other pollutants such as sulphur dioxide and dust.

“If you are going to have a greenhouse policy and be serious about applying it, then there is no economically viable large-scale power generation option other than gas,” Jones said.

“Western Australia has enormous supplies of some of the cleanest and cheapest gas in the OECD and clean coal technology will not be availabe for another 10 to 20 years.

“Very clearly the private sector thinks that gas is the preferrred option – 98% of privately owned electrivity generation in WA is gas-fired. Nor is there an energy balance issue – electricity generation is still dominated by Western Power and 68% of its generation is coal-fired. So if the government is looking to balance the mix of power generation, it should opt for gas.”

Tenders in for the new power station are due by tomorrow and the Government is expected to announce the successful bidder in September, with completion scheduled for 2007.