New data centre demand over next four years will be just a fraction of new home battery capacity

The federal government’s Cheaper Home Batteries Program has materially exceeded expectations, according to a new analysis from the Commonwealth Bank of Australia – so much so that household battery storage will vastly outstrip future data centre electricity demand.

A new analysis published by the Commonwealth Bank’s Global Economic & Markets Research (GEMR) team has seeks to unpack the impact of the Cheaper Home Batteries Program, and compare it with the big energy, social and political topic of the moment – the anticipated boom in data centre capacity and consumption.

The CBA report notes that the scale of expected home battery storage capacity is now much larger than previously expected and the latest AEMO Integrated System Plan now anticipated around 39 GWh of home battery storage capacity by 2030.

“If these batteries are assumed to discharge daily (i.e. once per day), batteries could discharge an equivalent of 14.6 TWh/yr (terrawatt hours a year), or 6% of forecast NEM demand in 2030,” the CBA analysts write.

“The surge in household battery uptake over the past 12 months has been very significant and takes material pressure off the national grid, particularly in the evening peak.”

The CBA says the 27 GWh of additional home battery storage now expected in the NEM by 2030 (compared to last year’s forecast, before the rebate took hold) is equivalent to 10 TWh of discharging capacity.

That compares to an additional 1.3 TWh of new demand now expected from data centres, when compared to previous forecasts.

Does this solve the reliability concerns in the NEM? CBA says the two are not strictly comparable, but says the surge in household battery uptake is a material positive development, as it will help to reduce tightness in the NEM, particularly by shifting rooftop solar into peak demand periods.

“The reliability benefits would be even greater if we see higher uptake of VPPs over time, or other coordinated grid support mechanisms,” it adds.

Home battery installations recorded between July 2025 and May 2026 reached 401,185, an increase of 209 per cent compared to the same period a year earlier. There are now over 450,000.

And even though rebates are being ramped down at a steeper pace than originally planned, the federal government has nevertheless allocated an additional $4.9 billion to the program, heralding the “much larger household battery buildout by 2030.”