More than 1000 hectares of Queensland government land will be converted into one of the biggest solar farms in the southern hemisphere.

Renewables firm Acciona Energy will finance, construct and operate the $500 million project, which is expected to power up to 122,000 households at full capacity.

At the Aldoga site on Friday, State Development Minister Cameron Dick said the solar farm would provide 240 temporary construction jobs and 10 ongoing positions once complete in 2020.

Mr Dick said the project would also deliver a much-needed economic boost to the once-thriving mining region.

"By setting that target of 50 per cent renewable energy production in Queensland by 2030, we can attract this sort of investment," he said.

"We've got one of the youngest gas and coal-fired power generating fleets in Australia and those power generators will still have a significant role to play when it comes to energy production, but we're now going to plug in the sun."