Solar and giant “water battery” to slash university’s grid consumption by 40%

Queensland’s University of the Sunshine Coast is set to slash its grid electricity consumption by 40 per cent, using a combination of 2.1MW of rooftop solar and a massive on-site “water battery.”

The unconventional system, designed and built in partnership with Veolia and now fully installed, will use the more than 6,000 solar panels to cool the water held in the three-storey tank, via a complex thermal process.

The solar PV, which spans across campus rooftops and carpark structures, will produce enough energy to cool 4.5 megalitres of water, effectively acting as a 7MW battery, the university said.

That stored, cooled water will then be used for air conditioning – currently the single biggest consumer of electricity at the Sippy Downs campus.

The system is expected deliver an estimated $100 million saving to the university over the 25-year life of the project, and slash emissions by more than 92 thousand tonnes for the same period.

For the USC, which is aiming to become carbon neutral by 2025, powering the campus’ entire air-conditioning needs with solar is a major step towards that goal.

“For a regional university to be leading the way on this is proof that we don’t need to be in the big cities to be taking big strides in new ideas in renewables, and for us that’s very exciting,” said USC vice chancellor, Professor Greg Hill.

“This technology has the potential to change the way energy is stored at scale and we are hoping other organisations take inspiration and indeed copy us.

“The team behind this is already sharing the technology with schools, universities and companies around the world.

Hill says the technology will also be used as a teaching tool at the University, with energy savings tracked and recorded through real-time monitoring across the campus.

In comments on the project in May, Hill noted that the thermal system would use environmentally friendly refrigerant gas, and campus lake water, thus averting the need to use potable water.

The project was also said to be including an automated system that would select the most appropriate energy source at any given time, whether that was stored chilled water, solar energy or electricity from the grid.

“On cloudy days when the solar isn’t operating at peak, the system will use grid electricity at night-time when electricity rates are lower,” Professor Hill said.

“The system will react to changing conditions on campus and select the best source of energy to minimise energy use, carbon emissions and cost.”

Veolia Australia CEO Danny Conlon said the company had also gained a lot out of working with the USC on “such a unique and complex” project.

“By working closely with the University, we’ve delivered a solution that makes them a leader in sustainable energy management in Australia,” he said.

“We’re delighted about the environmental and financial benefits this will bring them.”

Queensland energy minister Anthony Lynham, who attended the official switching-on of the solar and storage system, said it was evidence that major organisations were “taking up the challenge” laid down by the Labor government, which has targeted 50 per cent renewable energy by 2030 and zero net emissions by 2050.

“This $12 million project has created 80 local construction jobs and adds to more than 42,000 rooftop solar systems on the Sunny Coast, and the 520,000 residential solar systems across Queensland,” Lynham said.

“This is the power of renewable energy: it’s clean and saves money, which is a win-win outcome for the environment and the economy.”