Australian families could be saving up to $109 million more on electricity if the nation moved to a flexible export scheme for rooftop solar panels that has proven successful in South Australia, new data shows.

Though Australians are prolific adopters of rooftop solar, most households can’t export more than 5 kilowatts (KW) into the grid at a time because regulators are fearful of overloading the power grid.

But a recent trial of flexible exports in South Australia has allowed some properties to send up to 10kW into the grid when the grid isn’t overly congested – delivering windfall benefits to home owners and others.

Solar Analytics chief executive Stefan Jarnason has run the ruler over the program, and says the benefits could be enormous on a national scale, particularly as Australia moves away from fossil fuel electricity.

“Australia has the world’s highest uptake of rooftop solar,” Mr Jarnason said.

“But at times during the day we’re out at work and we’re generating more than we use, so we can export it back into the grid.”

Huge savings

Using data from 35,000 customers with rooftop solar, Mr Jarnason estimates Australia could save $109 million with flexible solar exports.

That’s because a third of Australian households are already using rooftop solar, meaning about 5 million megawatt hours in additional electricity could be pushed back into the grid every year.

“Flexible exporting lowers the cost of electricity for everyone, not just those with solar panels,” Mr Jarnason said.

“Recently, there have been times where all of South Australia’s energy demand has been met with rooftop solar panels.”

Traditionally, network operators in each state and territory have limited how much power houses with rooftop solar can export because it could end up overloading the grid, sparking blackouts.

But South Australia’s trial shows that when rooftop solar systems are synced with the internet and controlled through a central system, the amount exported can be varied dynamically to ensure the grid isn’t overloaded while increasing the amount of electricity that can flow back.

In other words, if it’s a sunny Sunday afternoon network providers might throttle the power rooftop solar owners export to limit congestion.

But when grid congestion is lower, the system can be throttled up to export much more power – though this does require households allowing regulators to control their rooftop solar systems.

Source: Australian Energy Regulator (click to enlarge).

South Australia’s trial is now being extended state-wide, but a national rollout could deliver enough electricity to power an extra 600,000 homes a year, Mr Jarnason estimates.

Mr Jarnasson said it’s now “absolutely inevitable” that the nation will follow South Australia’s lead in adopting flexible solar exports, arguing there are few, if any, downsides associated with it.

“Most of the time, about 99 per cent, you can export as much as you can,” Mr Jarnason said.

“The other 2 per cent of the time it’s reduced. It’s a rare occurrence.”

There are signs flexible exporting will become more widespread, with network providers in Victoria and New South Wales considering whether to take South Australia’s lead.

Victoria tested allowing households to increase their solar exports from 3KW to 5KW last year and in May announced a change that will see all new inverters installed with the capability to dynamically export by 2024.

Meanwhile, the Australian Energy Regulator (AER) is also currently reviewing regulations for the implementation of flexible solar exports, noting “rapid changes” in a recent consultation paper.

“When networks are not constrained, consumers can export more from their resources at times and locations where there is “spare” unallocated capacity, rather than be restricted to (potentially lower) static limits,” the AER wrote.