In winter 2025, low wind days were dangerous as they produced extreme spot prices. In winter 2026, low wind days have been far less influential. Battery storage has broken the link between low wind and high prices, making wind a less influential price driver than it was a year ago.
Low wind used to mean high prices
The June 2025 data tells the story. The two most extreme winter price days in recent NEM history both occurred on very low wind days:
- 12 June 2025: Daily averages of NSW $1,694/MWh, VIC $1,786/MWh, SA $1,636/MWh — wind in NSW was just 3,090 MWh for the day, while VIC had 2,067 MWh
- 26 June 2025: Daily averages of NSW $1,951/MWh, VIC $2,049/MWh, SA $1,970/MWh — again with NSW wind at 11,582 MWh and VIC at 5,799 MWh
These weren't outliers in isolation as the entire June 2025 average was dragged to $256/MWh in NSW and $265/MWh in VIC as a result. Low wind in May 2025 also produced $545/MWh in NSW on 13 May and $253/MWh on 14 May. The pattern was clear: when wind dropped exacerbated by base load outages, prices spiked.
Wind price-impact has weakened
Looking at April and May 2026, days with low wind output no longer produce the price spikes they once did. Grouping days by wind output band and comparing average prices across the two years we note the gap is largest at the low end of the wind range.
In 2025, low wind days in NSW averaged $140/MWh; in 2026 the same low wind conditions average $87/MWh. The ceiling has come down as the most impactful low-wind days in 2026 are producing prices that would have been considered moderate in 2025.
Early June 2026 reinforces this trend shown by the same month that produced the extreme price spikes a year ago. The first eight days of June 2026 have averaged $42–$84/MWh across all mainland regions, with no spike events.
Here are the results of measuring the average spot price for NSW and Victoria against wind production.
NSW — Average spot price by daily wind output
| Daily Wind Output | Apr–May 2025 | Apr–May 2026 | Difference |
|---|---|---|---|
| Low (< 10,000 MWh/day) | $140.6/MWh | $87.4/MWh | –$53/MWh |
| Mid (10,000–20,000) | $120.7/MWh | $73.2/MWh | –$48/MWh |
| High (20,000–30,000) | $95.4/MWh | $67.1/MWh | –$28/MWh |
VIC — Average spot price by daily wind output
| Daily Wind Output | Apr–May 2025 | Apr–May 2026 | Difference |
|---|---|---|---|
| Low (< 10,000 MWh/day) | $122.9/MWh | $103.3/MWh | –$20/MWh |
| Mid (10,000–25,000) | $102.4/MWh | $72.9/MWh | –$30/MWh |
| High (25,000–45,000) | $59.3/MWh | $38.9/MWh | –$20/MWh |
BESS has lessened the risk of low wind
The growing role of BESS is discussed in our May-26 Generation Trends report.
In NSW, average BESS discharge at the 18:00 peak grew from 214 MW to 738 MW year-on-year, while gas dispatch at that same interval fell from 730 MW to 224 MW — an almost direct substitution.
In QLD, BESS at 18:00 reached 988 MW (the highest in the NEM) as gas fell from 1,307 MW to 815 MW. As the report puts it: "Gas and hydro have been displaced from their traditional peaking role."
In 2025, gas set the marginal price when wind dropped in the evening; in 2026, batteries fill that gap before gas is needed. This means on low wind days, the growing BESS capacity will step-in and then if required, the gas powered sector will follow.
The result is a dramatic collapse in evening peak prices:
| Region | May-25 Evening Peak | May-26 Evening Peak | Change |
|---|---|---|---|
| NSW | $349/MWh | $103/MWh | –70% |
| QLD | $197/MWh | $104/MWh | –47% |
| VIC | $132/MWh | $88/MWh | –34% |
| SA | $133/MWh | $97/MWh | –27% |
It is this evening peak, the window that previously amplified low-wind conditions into price spikes that has been structurally defused.
Wind still matters — just differently
Wind remains an important price driver, but its influence in 2026 is primarily through daytime and overnight suppression rather than the price-spike risk it carried in 2025. High-wind days still produce the lowest prices evidenced by SA averaging near-zero or negative on the windiest days of April and May. However, the asymmetry has narrowed as high wind pushes prices down, but low wind no longer pushes prices to extremes.
Our Challenges Facing Renewables report shows that in the Regions with a large established wind sector (i.e. SA, VIC and NSW), wind's generation-weighted average capture rate has already fallen to around 60% to 75% of the flat baseload price. In contrast, QLD where the wind sector is still relatively new and small, captures 98%.
The disparity tells the story that as wind grows, it increasingly sells into a market it has helped make cheap. This cannibalisation pressure will only intensify as QLD's rapidly expanding wind capacity matures; but for now, the more significant structural story is that BESS has defused the low-wind price spike risk that made wind's absence so consequential in 2025
We'll keep watching as the transition unfolds. The next test will be whether June 2026 can avoid the spikes that defined June 2025.
Wind Generation versus Price Charts
These charts show daily wind generation alongside the average spot price for each day, comparing 2025 and 2026 across April, May, and June (to date).
April
May
June
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