Origin Energy has been awarded the tender to design, build, own and operate the 924 solar panels. It is one of the largest installations of its kind on an Australian building.

Tender documents published in October said the mint wanted to "reduce greenhouse emissions and total electricity costs through environmentally sustainable energy" via a solar photovoltaic energy generation system on the Deakin property's 900-square-metre roof.

Origin will operate and maintain the solar system, which will be installed in the coming months, and sell the generated solar energy to the mint via a 15-year power purchase agreement.

A Mint spokeswoman said the institution expected the panels to be ready for use in late November.

She said the system would have a power rating of 264 kilowatts, up from the 230 kilowatts outlined in the original tender, because of "

The solar cells will not be visible from the ground in order to preserve the building's heritage aesthetics.

The spokeswoman said the conserved energy was expected to save the mint 3 per cent of its annual costs.

Mint chief executive Ross MacDiarmid said the installation of the solar panels would reduce the mint's carbon footprint as well as save money.

"This move by the Royal Australian Mint will make a significant environmental impact by reducing greenhouse emissions and with a cost reduction, these panels are a real investment for the mint's future," Mr MacDiarmid said.

Origin energy markets chief executive Frank Calabria said Origin was pleased to be delivering a cleaner energy solution for the organisation.

"This is one of the largest solar PPA installations on a building in Australia to date, and demonstrates how large organisations are now making the most of solar energy," he said.

"Solar can deliver businesses benefits to both their bottom line and their carbon footprint, and it is great that the mint is leading the way for big business in Canberra."