Battery Rebate To Deliver A Coal Plant Of Power In 18 Months

The federal battery rebate is set to play a crucial role in reaching Australia’s new 2035 emissions target, with SolarQuotes analysis revealing that the power output of additional battery storage capacity installed under the scheme will soon match that of Australia’s largest coal plant.

How Much Storage Capacity Has The Federal Battery Rebate Added?

Since the launch of the Cheaper Home Batteries Program on July 1, roughly 161MW of home battery power has been added to the grid per month. At the current pace, the amount added in about 18 months will match the output of Eraring power station – Australia’s biggest coal-fired power plant. Australia’s ageing coal plants are forecast to reach the end of their life in the coming years as Australia moves to cleaner energy sources to achieve its 2035 emissions target.

Batteries Are Rolling Out Fast

Based on figures provided by the Clean Energy Regulator, 43,519 home batteries were installed across July and August with an average nominal capacity of 19.2kWh.

This rapid takeup could prove instrumental to Australia meeting its new 2035 target to cut emissions by between 62%-70%, given Australia is currently only on track to cut emissions by 51% by that date.

A particular challenge for the grid over the next decade under this transition is the planned closure of pollution-heavy coal plants, but the large number of home batteries rolling out offers a promising way to cover their loss through the storage of renewable energy.

Rebate To Match Australia’s Largest Coal Plant

Eraring coal station, located in NSW’s Hunter Valley.

To take one example, the Eraring coal-fired power station in NSW, Australia’s biggest, has a generating capacity of 2,922MW.

Origin, the energy giant that owns both Eraring and SolarQuotes, signed a deal with the NSW government in May last year to extend the ageing coal plant’s closure date out from August 2025 to August 2027, with an option to extend again to April 2029, but recent analysis from Nexa Advisory warns that the “43-year-old generator is unreliable and incompatible with today’s dynamic electricity system”.

Analysis by SolarQuotes’ resident fact-checker Ronald Brakels finds that at the current rate, it will take 7 months for new battery capacity installed under the federal rebate to equal one hour of Eraring’s generation at full output.

“While the batteries will be able to store just short of one hour’s of Eraring’s output after 7 months, they they won’t be able to discharge that much to the grid … if we assume each battery installation can discharge an average of 7.5kW … we’re looking at around 18.2 months before batteries installed under the federal incentive can match the power output of Eraring,” Ronald says.

If fully charged, the batteries could supply this power for 2.56 hours, but Australia also needs to continue to add to solar and wind capacity so the batteries can be reliably and cleanly charged.

“But it’s not necessary to match its power output to achieve an economic kill of Eraring – the point where it becomes cheaper to shut it down and meet evening demand using home batteries and a combination of other methods than to keep it running. Other methods can include demand management, efficiency measures, investment in open cycle gas turbine capacity, and more wind capacity. Currently open cycle gas turbines are powered by natural gas or sometimes kerosene, but they don’t have to be run off fossil fuels in the future,” Ronald says.

Breakdowns Plague Ageing Coal Plants

The rapid uptake of solar batteries comes as Australia’s coal-fired power plants become increasingly unreliable as they reach the end of their life, with most of the country’s coal-fired power capacity over 40 years old. There were 128 unplanned coal unit break-downs over the previous summer – eight times more than the Australian Energy Market Operator forecasted.

Rooftop solar is already playing a key role in the transition away from coal, with Australia now boasting more household solar capacity than all remaining coal-fired power stations in Australia. The addition of batteries to store excess solar will further diminish the need for coal at times such as during peak evening periods.

There is a similar picture globally, with the International Energy Agency predicting renewable electricity generation will overtake coal this year, as warnings grow around the catastrophic impacts of climate change.

For more on the federal battery rebate, read our dedicated explainer page. To find out if a battery is right for you, read our deep dive on solar batteries.