The ABC has reported that the energy company, Alinta, has announced plans to convert two coal-fired power stations to solar thermal technology.

Alinta had been planning to close the 240 megawatt Playford B coal-fired power station in Port Augusta later this month. The 520 megawatt Northern coal-fired power station, also in Port Augusta, had been expected to be operated for only six months a year.

It is estimated that the Playford B power station emits 1.77 million tonnes of greenhouse gases a year and that the Northern power station emits 3.62 million tonnes of greenhouse gases a year.

The new announcement follows a visit to Port Augusta last week by Greens leader, Christine Milne, when she called for conversion of the coal-fired stations to solar-thermal power.

It is expected the solar-thermal option will create 360 full-time jobs but could cost as much as three times the amount of a gas-powered plant.