The company responsible for Australia’s biggest CBD solar installation has invited public investment, making it the first community renewables project in Australia with a public share offering.

Sydney Renewable Power Company’s 520kW solar installation on top of the new International Convention Centre in Darling Harbour is the size of 12 tennis courts and will generate enough electricity to power about 100 homes each year.

Andy Cavanagh-Downs, the founding director of the project – which was set up and is run by a volunteer board – said he believed it was the first volunteer-run, for-profit company in Australia.

Cavanagh-Downs said the company’s founders wanted to find a way to involve the public directly in transitioning the economy away from fossil fuels.

“We’re clearly going to undergo a change as we move from a high-carbon to a low-carbon economy,” Cavanagh-Downs said. “Change can be awkward to deal with and the more you involve people in that process, the more that they’re part of it, the quicker and easier that change can come about.

“The other bit that we thought was attractive was – not everyone can put solar on their roofs.

“This is a really good way for renters and apartment-dwellers to invest in solar.”

The group will sell 519 shares in the unlisted public company, raising almost $1.5m to repay the loan that was used to finance the project.

Most of the company’s revenue comes from an agreement with the managers of the International Convention Centre, who will buy all the electricity produced by the installation. The company will also sell the renewable energy certificates it gets through the federal renewable energy target.

Each share, which costs $2,750, is roughly equivalent to owning 1kw of capacity and the company is expecting to make investors a return by paying dividends of at least $35,000 after the first seven months of operation, amounting to about $105 per share after the first year. That figure should increase each year, since the power purchase agreement includes a price increase of 3% each year.

In addition, the company will divide up its capital each year, distributing it to investors, since it aims to wind up after 25 years.

The project faces risks from a range of factors, including the potential of reduced solar output from bad weather or new buildings nearby creating shade.

Cavanagh-Downs said the company had no immediate plans to raise capital for any further projects but the board was keen to share its experience with others who were interested in creating similar projects.