One Step Off The Grid

The northern New South Wales city of Lismore on Tuesday formally opened the country’s largest floating solar installation, and flagged plans to increase its size five-fold or more and to add battery storage.

The 100kW floating solar farm is installed on the East Lismore sewage treatment plant, and along with a 100kW solar installation at a local aquatic centre forms a key part of the local council’s plan to source 100 per cent of its electricity needs from renewable energy by 2023.

Also planned is a 5MW ground mounted solar farm – with a scoping study already underway -.

But it is both the choice of a floating solar farm, and the ground-breaking community ownership model that makes the Lismore installation unique in Australia.

The two 100kW installations were largely funded by community members under the “Farming the Sun” initiative, which combines community funds with the council balance sheet to enable projects to go ahead.

“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,” Lismore Mayor Isaac Smith said.

He said he hoped 2018 would be a “breakthrough year”, when “even the worst of the (climate and solar) skeptics realise that the time has come.”

Ben Franklin, the local National Party MP, and the state’s secretary for renewable energy, said it was an example of change in the electricity market in the way that power is generated, distributed, and valued.

“It is the first community owned council investment model of its kind, and it shows the hunger in the community when the shares were snapped up so quickly,” he said.

“It shows the community is passionate about renewable energy, and that is will put money where their mouth is. This is the future, and today in Lismore we are part of it.”

The floating solar farm was switched on earlier this month and will provide about 12 per cent of the sewage plant’s annual electricity needs.

Lismore Council’s environmental strategies officer Sharyn Hunnisett said a decision to expand the facility to 500kW, or possibly more, would be made this year.

It is likely to follow the same community funding model, where the community lent money to the council to build the project, and then repaid with interest at a commercial return to the investors.

Hunnisett said battery storage would also likely be added when its costs reduced sufficiently. At that stage more solar would be added and the excess output stored for use at night.

The innovative floating design – using technology from Ciel et terre Hydrelio, and installed by Adelaide-based Suntrix, provides capacity for the solar farm to expand across the overflow ponds. Council’s aim is to eventually power the treatment plant from 100 per cent solar energy.

The floating solar plant also has some unique advantages. It operates at a cooler temperature than other solar farms, so has improved efficiency, reduces evaporation, and solved problems about where to install solar.

Hunnisett said the financial model – the first of its kind in Australia – has attracted interest both nationally and internationally, and many council representatives were on hand for a technical briefing at the plant after the opening.

“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.”

The floating solar farm technology features 1,200 floats, 280 solar PV modules (each of 355Wp), and 15 on shore and in water anchors and restraining systems.

The largest floating solar systems currently under construction are a 13.7MW system in Japan, to be opened In March, and a 70MW project in China.

Floating solar farm stats:

The East Lismore Sewage Treatment Plant is Council’s highest electricity consuming site (1,577,726 kWh annually), which accounts for 27% of Council’s total electricity consumption.

The 100kW floating solar farm will produce around 12% of the site’s needs (178,437 kWh annually) with a saving of $24,000 per annum and a payback of 11.6 years.

Lismore Council’s renewable energy goal stats:

Council needs to generate 6,600MWh of renewable energy to reach its goal – equivalent to 825 households.

Council started with 1% renewable energy in 2014. Council will be generating 14% by the end of this financial year.

Council’s large-scale solar plant will be 5MW.

Council’s electricity use has decreased 20% since 2010.

Council’s energy costs in 2013 were $1.6 million – last financial year costs were down to $1.1 million.

Council has saved 8,611 tonnes of CO 2 in seven years. This is equivalent to taking about 1,800 cars off the road.

This article was originally published on RenewEconomy’s sister site, One Step Off The Grid, which focuses on customer experience with distributed generation. To sign up to One Step’s free weekly newsletter, please click here.