Energy Minister Eric Ripper said Western Power would spend $94million over the next decade to develop renewable energy use and cut harmful emissions.
The green light for the wind farm cements the place of the Mid-West as the centre of an emerging wind farm province.
Ripper said the investment would result in a 60% increase in the amount of renewable energy sold by Western Power every year with the 40-megawatt first stage of the wind farm able to generate enough power for 25,000 homes.
The second green project given the nod was a small biogas plant south of Mandurah.
The two projects would slash greenhouse gas emissions by 138,000 tonnes a year, equivalent to taking 35,000 cars off the road.
The Minister said the new wind farm was one of 10 in the feasibility, planning or construction stages. There were already eight wind generators already operating in Western Australia.
Ripper said the Emu Downs wind farm, 30km east of Cervantes, would be a joint venture between the Stanwell Corporation and Griffin Energy, with Western Power as the main customer. Some 25MW of the 40MW first stage of the wind farm would be sold to Western Power and the remainder would be available to further develop the local renewable energy market.
The wind farm was expected to be operating by the end of 2005.
The biogas plant, south of Mandurah, would be developed by a local engineering company. The plant would use bacteria to break down various forms of biomass - usually green waste sourced from the Mandurah region - to produce a biogas to fuel a 1.2MW generator from late 2004.
"By recycling waste that would otherwise end up as landfill, this project is likely to make a major contribution to improving the local environment," the Minister said.