Australia is home to the planet’s biggest battery. It is also the world’s leading market for household batteries.
But Canberra researchers suggest medium-sized batteries — shared between several hundred homes — could be just as crucial for the energy grid’s future.
- The ACT Government is considering a community battery for the suburb of Jacka, to be shared among households
- Research suggests shared, mid-sized batteries are a cheaper, more effective way for homes to store solar energy
- The network operator is looking for ways to stop households flooding the grid with excess solar power
The ACT Government is considering giving residents of a new suburb shared access to such a battery, which would be about as big as a shipping container.
The proposal would benefit up to 500 homes in Jacka, a community that will have solar cells on every roof.
If it goes ahead, it will store households’ unused energy, earning them more money and preventing their excess electricity from destabilising the power grid — a problem of growing concern to the grid’s operator.
It will also allow more people to benefit from battery technology, which to date has been used almost exclusively by wealthy households.
‘Cheaper and more efficient’
Community-scale batteries are not yet used in Australia’s biggest energy network, which includes South Australia and all eastern states.
However, modelling by Australian National University (ANU) researchers shows the mid-sized batteries can be cheaper and more effective than household batteries.
A research leader of the ANU’s battery and grid integration program, Marnie Shaw, says Australia has the world’s highest rate of rooftop-solar generation, and needs ways to store that electricity.
“Batteries save households money because they allow you to use solar energy that you produce during the day later in the evening when you need it, and that energy will be cheaper than buying energy from the grid,” she said.
“So having any kind of battery storage will be cheaper for households.
An ANU simulation of a battery linked to 200 homes suggested each household would save about $15 a month in power costs in today’s energy market.
But one of the main beneficiaries would be the power network itself, as the battery would substantially reduce the amount of solar energy flooding the grid during daylight hours.
Batteries can stabilise the grid
Last month, the Australian Energy Market Operator (AEMO) said it needed the power to stop households exporting their excess electricity at critical periods, to avoid damaging the grid.
Its chief executive, Audrey Zibelman, said AEMO would do this only during emergencies.
“This is very temporary, very limited and, really … a last-resort control we need if we were worried the system would otherwise go black,” she told 7.30.
However, the growing use of batteries is already beginning to solve this problem.
Dr Shaw’s early modelling suggests household batteries can lessen potentially damaging energy flows during peak periods by about 25 per cent, while a community battery can be up to twice as effective.
But she says all types of power reserves — home, community and large-scale — are important for the network.
Government keen, but deal not yet done
The ACT passed a milestone last year when its entire electricity use was matched by purchases from renewable sources.
This means Canberra is now effectively 100 per cent powered by green energy, though still reliant on Australia’s main grid.
Deputy Chief Minister Yvette Berry said suburban planning was an important part of fighting climate change.
However, the Jacka battery remained a proposal at this stage, which the Government was examining with the ANU and power utility Evoenergy.
“There’s a lot of work to do in that space, because innovation is happening every day in battery storage and solar energy,” she said.
“So we want to make sure we get it right.
The Government is also trialling other ways to improve green energy use and efficiency in new suburbs.
In Whitlam, for example, it is subsidising home owners who buy rooftop solar, electric vehicle charging points and efficient appliances.
However, Dr Shaw said one of the main advantages of a community battery, compared with other initiatives, was it could benefit a wider range of people.
“This is one of the problems with household batteries — they require a large upfront investment and that’s out of reach for some people.”