Households with solar batteries will be able to make money from their electricity storage capacity, thanks to new energy market rules.
The changes announced on Thursday are part of broader moves by the Australian Energy Market Commission to open up the national electricity market for both grid and household scale batteries.
The AEMC said homes set up with rooftop solar and storage will be able to sign up with "aggregator" businesses, which trade in the bundled-up capacity of many different energy users, and will pay for using home batteries when needed.
AEMC chair Anna Collyer says the reforms acknowledge that the national energy market is no longer one-way.
"The energy market is moving to a future that will be increasingly reliant on storage to firm up the expanding volume of renewable energy," she said in announcing the change.
The AEMC expects installed storage such as batteries will increase by 800 per cent over the next two decades.
Victoria plans to install a 300 MW battery near Geelong before next summer, while Origin Energy is building a 700 MW battery at its NSW coal-fired plant at Eraring in the Hunter Valley.
The AEMC reforms also create a new market for energy providers that can respond at lightning-quick speeds, to provide stability when the grid is under stress.
"As our energy mix continues to change, we will need these new, ultra-fast options," Ms Collyer said.
"They're like an insurance policy for keeping the energy system in balance and avoiding blackouts," she said.
Until now, the fastest service available in these specialised ancillary markets was six seconds, but the reforms could should see response times of one or two seconds, provided by grid-scale batteries.
Existing large-scale installations such as South Australia's Hornsdale battery have already slashed prices for ancillary power, a market traditionally dominated by gas-fired stations.
Under the current system, batteries have to register to participate in the market twice - to draw energy from the grid, and also to send it out.
The commission says it is planning to make the rules more flexible, so they work for services that have not even been invented yet.
"If we make the rules more elastic to focus on what market service you offer rather than who you are, they will stay relevant in the face of rapid change and support energy innovation," she said.