NSW Planning Minister Kristina Keneally announced today the power stations, proposed by Energy Australia and Delta Electricity, had been approved for a site north of Marulan.

The stations, worth $800 million, have the potential to generate up to 800 megawatts of electricity and support about 500 construction and 20 ongoing jobs, Ms Keneally said.

"These power stations will deliver an economic and employment boost to the Southern Tablelands as well as help secure the state's energy supply," Ms Keneally said.

Energy Australia's proposal is for a 350 megawatt peaking power station.

The Delta Electricity station would be rolled out in two stages: the first a 250-350 megawatt gas-fired peaking power station, while stage two would involve converting that station into a base load 400-450 megawatt facility.

Ms Keneally said a concept plan had also been approved for gas and water supply pipelines and transmission line infrastructure.

"Because the stations are situated next to each other, they have agreed to share supporting infrastructure," Ms Keneally said.