The transformation of a coal-fired power station into a 42MW solar farm in Collinsville, north Queensland, is set to begin after the project reached financial close on Monday, with a $60 million commitment from the Clean Energy Finance Corp.

The $100 million project, which is being developed by the Australian arm of Thai company Ratch, marks the 10th project the CEFC has financed through its Large-Scale Solar Program – a total estimated project value of $900 million and a total generating capacity of more than 400MW.

Ratch Australia said on Monday that reaching financial close meant that construction of the 42.5MW solar farm – which was also a recipient of $9.5 million of ARENA grant funding – could start within weeks.

It follows the signing of a power purchase agreement in March, a deal with Alinta Energy to buy the PV farm’s electricity and large-scale generation certificates until the end of 2030.

“This significant milestone means we can now get on with construction of this project and if all goes to plan it will be generating electricity within roughly 12 months from now,” said Ratch’s executive general manager of business development, Anthony Yeates.

“It is really satisfying to get this project underway after such a long development process. We first started looking at solar power options for the site back in 2010 under the old Solar Flagships program.

“After considering lots of alternatives, we will be building a large array of solar PV panels that will generate electricity in essentially the exact same manner as the solar panels that are installed on house rooftops.

“CEFC and ARENA are very focussed on helping projects like ours proceed and we have certainly benefited from their experience with similar projects,” he said.

CEFC large-scale solar lead Gloria Chan said the green bank was particularly excited about the Collinsville project’s potential to showcase how old power station sites can be repurposed for renewable generation.

“Since our program’s launch in September 2015, the large-scale solar sector has transformed. Solar has become a progressively cost-competitive energy source and we are now at the tipping point of seeing Australian utility-scale solar projects becoming commercially viable without grant funding,” Chan said.

The 180,000-panel project will take advantage of existing electrical infrastructure including substations and Ergon Energy’s distribution network.

It is expected to be operational by June 2018 and produce enough energy to meet the needs of almost 15,000 homes.