daily · Clean Energy

Battery growth quadruples to 27 GWh and starts lifting midday wholesale power prices in Australia's NEM

Australia's National Electricity Market has undergone a structural pricing shift as grid-scale battery storage expanded from 5.5 to 27.1 gigawatt-hours, pushing midday prices from near zero to $25-30 per MWh, according to an AEMO data analysis published October 22, 2026. Battery charging demand is now outpacing solar's price suppression at midday while cutting evening peaks by an estimated $63 per MWh.

By Greener Numbers Editorial Team · Published October 22, 2026 · Updated 10/22/2026

Grid-scale battery storage is beginning to push midday wholesale electricity prices up across Australia's National Electricity Market, reversing the price suppression long caused by rooftop and utility solar, according to an analysis of AEMO data published by Renew Economy on October 22, 2026.

Over the 30 days to October 7, the NEM average spot price ran at $68 per megawatt-hour against $59 a year earlier. Midday prices climbed from around zero to $25-30 per MWh, a rise that outweighed a fall in the evening peak from roughly $130 to $95 per MWh. Part of the overall increase is seasonal - spring evening peaks are modest, leaving batteries less to shave - but the midday increase itself marks a structural shift: growth in battery charging demand is now outpacing growth in solar generation during the middle of the day.

A multiple regression on the AEMO data, with explanatory power around 68%, attributes a $29 per MWh midday increase and a $63 per MWh evening decrease to the expansion of grid battery storage from 5.5 to 27.1 gigawatt-hours. Reduced wind output at midday added a further $8 per MWh.

The inversion carries mixed implications for the energy transition. Over a full year, lower evening prices have so far mattered more to average costs than higher midday prices, and battery charging continues to soak up surplus solar that would otherwise flood the market. But the shift signals that the era of free midday solar is ending, changing the revenue math for new solar projects even as it strengthens the case for storage.

Official source: reneweconomy.com.au ↗