Solar panels love the sun. But the heat? Not so much.
A Western Australian-developed technology that can keep solar panels cool to optimise generation efficiency and capture the excess heat for other uses is on track for deployment in Europe.
Sunovate’s technology is a type of solar PV-thermal (PVT) system that draws heat away from the panels and reroutes it to another use, such as space heating or a heat source for heat pumps.
Glen Ryan, a renewable energy engineer behind the Bombora wave power technology, co-founded Sunovate alongside managing director Cesira Leigh after learning that his household solar system was underperforming on hot summer days when he expected it to be generating at peak efficiency.
The company in 2019 attracted attention from the World Energy Congress as one of the top 100 international start-ups in the field of energy transition. It was also recognised at Climate-KIC’s Climate Launchpad competition, and has been named a partner in the RACE for 2030 CRC, a federal government backed research partnership to support a customer-centred clean energy transition in Australia.
The company is currently monitoring a protype project in Perth that is showing promising results so far, with the system achieving up to 50 per cent conversion efficiency.
The small team experienced a few setbacks during Covid, but Ryan expects to make the first sales of the product pending a successful trial.
It gets hot on the roof
The way rooftop solar panels are typically installed in Australia – flat against the roof – make the panels even hotter because hot air gets trapped unearth them. A tin roof, which reflects heat, exacerbates the heating effect further.
Ryan’s tech solves this problem by cooling the panels with air and collecting excess unused heat from the PV module and using it to heat space and water, or it can be used with a heat pump for industrial and commercial applications.
On average, he says a 10°C temperature drop improves efficiency by 4-5 per cent, with newer panels typically better equipped to handle the heat.
While some other PVT systems use liquids for heat exchange, Ryan’s company has opted for an air-based transfer mechanism because it can service multiple functions at once and it “can’t boil and it can’t freeze.”
“We can also dump it into the atmosphere with no consequences.”
The other benefit of using air heat transfer is it’s compatible with the traditional ducted heating solutions in many Australian buildings.
The technology can be retrofitted onto existing solar systems as well as installed new.
Ryan also expects the technology will increase the longevity of solar panels.
Large scale applications first
Ryan says there’s a lot of interest in domestic applications but the company is wary of targeting residential sector initially because each installation is unique.
“Roofs don’t tend to accommodate AC at the best of times so every solution becomes quite bespoke.”
The plan is to focus on commercial markets where the integration piece is easier, and volume can be achieved quicker.
“Once you get volume, you can bring costs down.”
Agricultural and industrial settings that use heat (up to 150 degrees Celsius) for processing goods are suitable early candidates, he says.
So far, Ryan is seeing interest from European customers, as well as a few mining companies in Australia. He says Europe is a more mature market for low carbon thermal energy solutions, with the New Green Deal in the EU offering attractive policy settings for the technology.
“Europe is ten to 15 years ahead of Australia in some of these aspects.”
European countries also have a lot of infrastructure that is compatible with PVT, such as district heating and cooling.
He says that once the company carves out some clear customer pathways it will be able to invest in lower cost manufacturing and deployment. Eventually, he imagines the technology will be suitable for homes.
“As an emerging tech we need to be laser focused on where to employ the product first.”
What it will take for Australia to catch up
Ryan initially saw promise for PVT in the Australian market with its hot climate but has since shifted the focus to Europe where there’s a big appetite for low carbon heat.
He says few organisations in Australia understand the low carbon thermal energy space well.
“People think natural gas is clean.”
There’s also a little in the way of policy on renewable heat, with clean electricity the focus of targets and technology development in Australia.
He’d like to see renewable heating targets in Australia to help technologies like PVT to enter the market.