Prime Minister Julia Gillard has approved the construction of the southern hemisphere's largest solar power project on Queensland's western Darling Downs.

She made the announcement while touring the Kogan Creek coal-fired power station near Dalby, north-west of Brisbane.

CS Energy will spend $104 million installing solar panels at the plant which will generate an extra 44,000 megawatt hours of electricity per year.

"I am very confident this project is going to be a standout - a standout in Australia, a standout in the world - about how power generation can be changed to give us a cleaner-energy future," Ms Gillard said.

Ms Gillard says the project could be one of many under the new carbon tax scheme.

"With the clean-energy future I want for our nation, I want it to be a norm," she said.

"That's why we have to price carbon, to create the right incentive that we do have a clean-energy future."

Ms Gillard says the project will prevent the release of 35,000 tonnes of carbon into the atmosphere.