Network congestion is stopping millions of Australians selling their surplus solar power to the electricity grid, but a trial of new technology to unblock the network could deliver a hip-pocket boost to householders across the country.
The Australian Renewable Energy Agency (ARENA) is working with network operators and fitting smart inverter technology to 600 houses in areas where the network is most constrained so access to feed-in tariffs for supplying the grid is fairer.
Most rooftop panels lack technology to regulate supply into the grid.Credit:Glenn Hunt
"With household solar continuing to grow, it is really critical that we can maximise the potential of rooftop solar," said ARENA chief executive Darren Miller.
Export limits are placed on rooftop solar panels at the time of installation, which disadvantages households that had their panels installed most recently – particularly in areas with the highest uptake of panels.
Because those panels cannot regulate output, to avoid overload, networks have to set limits calculated by capacity on the sunniest day. That means the opportunity to take maximum power supply on cooler days is missed.
"Just as we wouldn't stop people driving just because the roads are gridlocked a few hours a week, it is not fair to stop people exporting solar power from their homes just because the grid is congested a few hours a week or a few days a year," Mr Miller said.
"At present, solar owners who got in early are able to sell their surplus electricity back to the grid without limits, but late adopters are restricted – which is also unfair."
ARENA and network operators AusNet in Melbourne and SA Power Networks in South Australia are conducting the trials, worth a total of $4.8 million.
"A smart and flexible solution for solar energy exports is a win-win," said Andrew McConnell of AusNet Services. "It means more Australian homes and businesses can benefit from solar panels, and that our energy mix becomes cleaner overall."
Australian government feed-in tariffs for households that supply solar power to the grid have led the country to the highest installation rate in the world. More than 2 million of the nation's 13 million homes have been fitted with panels. Around 200,000 rooftop solar systems are being installed each year across the country.