A floating solar farm built on a sewage treatment plant in Lismore has been officially switched on.

The 100-kilowatt project – a result of a partnership between the council and community solar energy facilitator Farming the Sun – will generate enough electricity to cover 12 per cent of the plant’s needs, saving about $24,000 a year, with a payback of 11.6 years.

The design means the solar can be expanded across the plant’s overflow ponds, with the goal to eventually go 100 per cent renewable.

Opened by parliamentary secretary for renewable energy and Northern NSW Benjamin Franklin, the launch event also featured Climate Councillors professors Will Steffen and Lesley Hughes, Lismore mayor Isaac Smith and local solar farm investors.

“This is an historic occasion for Lismore. We have demonstrated that you can collaborate with your community and provide renewable energy solutions for a regional city,” Mr Smith said.

“I am so excited our local investors were here to celebrate this milestone. It is their conviction and passion to see a renewable energy future that has made this project a reality.”

The solar farm, along with another 100kW system at Goonellabah Sports & Aquatic Centre, was funded by 20 local investors under a first-of-its-kind financial model under the Lismore Community Solar Initiative.

Lismore City Council environmental strategies officer Sharyn Hunnisett said the model had already generated interest nationally and internationally as a model of government/community cooperation.

She said the local investors were getting a rate of return better than that of a bank.

“The project has not been without its challenges to establish and get operational, but now that we have done the hard work we have a model others can emulate,” she said.

“We hope to see renewable energy projects like this taken up between councils and communities right across Australia, whether that’s using sun, wind or wave technology.”

The project is part of the council’s strategy to generate 100 per cent of its electricity from renewables by 2023.

In 2014 just one per cent of council’s electricity was being supplied by renewable energy, though at the end of 2018 it is expected to jump to 14 per cent.