Australia's consumer watchdog is sounding the alarm over sluggish enrolment in virtual power plants, warning that energy companies must convince millions of households to share control of their home batteries with the grid — or face significant cost blowouts in the country's multibillion-dollar shift away from coal-fired power.

A new report from the Australian Competition and Consumer Commission (ACCC) has found that while a surge in home battery installations is delivering real savings for individual households and pushing down wholesale electricity prices, the broader grid benefits remain largely "incidental" because too few batteries are being charged and discharged in a coordinated way.

What Are Virtual Power Plants and Why Do They Matter?

Virtual power plants are cloud-based networks operated by power retailers or technology companies that aggregate thousands of household battery energy storage systems into a single, coordinated resource. In exchange for allowing their provider intermittent access to their stored electricity, participating homeowners receive financial credits on their power bills.

Because home batteries can soak up cheap, abundant solar energy during daylight hours and release it back into the grid after sunset — precisely when demand peaks — a well-coordinated network of these units can meaningfully reduce reliance on coal and gas generation. The ACCC noted that co-ordinated batteries can more reliably and efficiently respond to price signals, reducing the need for expensive grid-scale storage, improving system reliability and ultimately lowering costs for all electricity consumers.

Federal government rebates introduced around a year ago have triggered a threefold increase in home battery uptake, cutting bills for those who have adopted the technology and easing evening peak demand across the wider grid. But the ACCC says these gains are a fraction of what could be achieved if more batteries were operating in concert.

Participation Rates Are Falling Well Short of Targets

The gap between where Australia is now and where it needs to be is stark. Currently, only around 3 per cent of east-coast electricity customers have a home battery installed, and of those, just 24 per cent have enrolled in a virtual power plant scheme.

Under the Australian Energy Market Operator's 25-year blueprint for the least-cost transition away from retiring coal generators, approximately 26 per cent of households would need batteries by 2050, with more than half of those units participating in virtual power plants. At present rates, Australia is a long way from either target.

Robbie Campbell, chief executive of Plico — a company that installs batteries and operates a 5,000-household virtual power plant in Western Australia — said the consequences of inaction were straightforward: more investment in gas-powered "peaker" generators to cover shortfalls during periods of high demand.

"A battery sitting in a garage doing its own thing doesn't displace a gas peaker — a battery in a virtual power plant does," Campbell said. "Right now, most of them are sitting in garages."

Trust, Not Technology, Is the Barrier

Campbell was emphatic that the problem is not a technical one. The hardware and the software exist to make virtual power plants work at scale. The obstacle, he argued, is consumer trust — and an industry that has not done enough to explain how these schemes actually operate or what participants stand to gain.

"Households aren't going to subsidise the grid out of goodwill," he said. "Show them the money, show them how it's made, and they'll stay in a virtual power plant."

The message is clear: financial incentives need to be transparent, meaningful and well-communicated if energy companies hope to shift enrolment rates from a trickle to a flood.

Some Experts Push Back on the Pessimism

Not everyone agrees the situation is as dire as the market operator's modelling implies. At least one energy analyst has suggested that assumptions about how batteries behave outside of virtual power plant arrangements may be overly gloomy. A growing number of retail electricity products, it is understood, are being structured to encourage home batteries to absorb low-cost or no-cost solar energy at midday — behaviour that may be delivering grid benefits even without formal virtual power plant enrolment.

Even so, the ACCC's broader conclusion is widely shared across the sector: the energy transition's economics depend heavily on unlocking the collective potential of Australia's growing fleet of home batteries, and that will not happen without a concerted push to bring more households into coordinated networks.

With coal plant retirements accelerating and electricity demand set to grow as more Australians switch to electric vehicles and home heating, the window to get virtual power plant enrolment right — and avoid locking in expensive alternatives — is narrowing fast.