Australia’s rooftop solar boom can be good news for networks: study

A new study has demonstrated the key role that distributed solar and storage could play in managing the shift to renewables, transforming Australia’s world-leading uptake of rooftop PV into a major asset to networks, rather than the liability it is often portrayed.

The $5 million ARENA-backed Networks Renewed project, led by the University of Technology Sydney’s Institute for Sustainable Futures, teamed energy network incumbents with tech innovators to find distributed energy solutions to network side problems.

The trial was conducted in Collombatti and Bellingen in regional NSW, and Yackandandah in regional Victoria – an area of “network constraint” in the state where a group of 90 homeowners with solar have been given subsidised battery storage, inverters and smart gateways.

What they found was that both solar and batteries can support network voltage – which translates into a success, the report notes, that opens the door to a suite of new business opportunities “based on the premise that rooftop solar can be an asset to everyone.”

It also means that the solar PV hosting capacity of Australia’s networks could be increased, allowing more opportunities for homeowners with solar systems to export energy to the grid and be paid for doing so.

These are important findings for a number of reasons, not least of all to counter the proliferation of mainstream news reports that cast Australia’s booming uptake of rooftop solar as a thorn in the side of networks.

As UTS research author Dani Alexander explained to RenewEconomy on Monday, this is not strictly accurate.

“Coming into this project we were quite clear that solar was not the cause of all voltage problems, but rather, solar was just unveiling existing voltage problems.

“We need to be very clear – it’s not about [rooftop solar and batteries] solving the problems they’re causing, but it’s being a part of the solution to a broader problem.

“We wanted to show that distributed solar is the tip of the iceberg, and underneath there are all of these unseen opportunities that we should be able to tap into if we can show that they work.”

And show this, they did.

Crucially, the study found that smart management of behind the meter solar and storage is not just about managing “real power” – or load shifting – but about providing vital “reactive power” services, allowing the networks to control and optimise voltage across the grid; a first in Australia.

According to the results, voltage was substantially corrected in two low voltage networks, with some positive impact observed at the high voltage level.

The project also successfully integrated DER-based voltage support services into network operating practices, with four inverter types successfully controlled via Reposit (NSW) and Mondo (Victoria).

“Not only did the trial prove that voltage can be managed during high solar export periods – it also proved that VPPs can successfully be used to manage network constraints when they occur,” said Dean Spaccavento, the CEO of Reposit Power, whose energy tech business provided the “smart gateways” for the NSW part of the trial.

The three-year study also demonstrated the vital role that teamwork will play in making Australia’s transition to renewables a success.

Alongside Reposit, the project brought together fellow energy technology leader Mondo (in Victoria), network operators AusNet Services, United Energy and Essential Energy, and the Australian PV Institute.

“A part of this project – the fascinating aspect to it, but one that required quite a lot of time – was bringing all the partners together so that we had this core goal,” said Alexander.

“We need those incumbent businesses and then the niche innovators coming in … and this was a fabulous representation of how it can work really well, bringing in all those partners, as well as state governments, and ARENA.

“We need to have everyone involved in solving the problem, otherwise the risk is you end up with a lot of very specific solutions that can’t be implemented outside of their own setting,” she said.

The engagement of customers was also largely a success, with those who participated in the trial said to be happy with their involvement, and keen to engage further, and more deeply, with their energy production and use in the future.

“From the customer side we had really positive feedback and interest early on,” said Alexander, who noted that in some parts of the study, 30 per cent of customers approached to take part signed up.

“By partnering with our customers, we demonstrated a new way to maximise their solar generation and enable our rural networks to host more solar power,” said Alistair Parker, the executive general manager of regulated energy services at network operator AusNet Services.

Chantelle Bramley, who heads up strategy, regulation and corporate affairs at Essential Energy said the project had provided real-world evidence of how distributed energy resources can improve outcomes for customers and networks.

“This type of capability is vitally important as we look to support greater penetration of renewable generation, maximise value to customers, while maintaining downward pressure on network charges,” she said.

But of course, there’s a way to go yet.

While the Networks Renewed project has demonstrated the multi-layered value of distributed solar and storage, “deeply integrating” these capabilities into the electricity system is another matter.

“We have demonstrated that it can be done,” Alexander told RE. “It’s the ‘seamlessly’ part that still needs to happen. …The set and forget.”