Commercial Energy Report – May 2026

May was the month winter pulled into the wholesale market. A single cold front on Monday 18 May pushed daily averages above $170 per MWh across NSW, QLD and VIC, with the same morning recording the lowest renewable share of the month at 17.7 percent. That one day did most of the work behind a 37 to 81 percent jump in monthly averages across the mainland.

This report covers the mainland National Electricity Market (NEM), the wholesale market run by the Australian Energy Market Operator (AEMO) that connects QLD, NSW, VIC and SA. Tasmania is outside scope. Prices shown are wholesale spot prices, not retail contract rates, though sustained spot movements feed into where retailers price contracts at renewal.

May 2026 monthly averages

What drove the month

Three things lined up in May. First, the seasonal shift into winter morning peaks across the southern states, with cold conditions across NSW and VIC pulling demand up at exactly the time solar output is at its weakest. Second, a low-wind window on 18 May took renewable supply to its monthly floor of 17.7 percent at 05:00, the same morning all three eastern states recorded their daily peaks. Third, coal availability stayed reasonable but did not have the headroom to absorb the demand spike without spot prices clearing well above $170 per MWh.

The contrast with the renewable maximum on Friday 8 May (73.8 percent at midday) shows the operating range the grid is now running between. Procurement timing within a billing period matters more than it did even two years ago, because the spread between high and low renewable windows is wider than it has ever been.

What this means for your contract

For businesses with a renewal in the next six months, the May data is a useful checkpoint rather than a signal to move. ASX Energy forward markets for CY27 and CY28 did not respond meaningfully to the spot strength, which tells you the market still views May as a winter event rather than a structural reset. That said, the gap between the cheapest mainland forward curve (VIC) and the most expensive (NSW and QLD) has not closed, so state-by-state pricing still matters when comparing offers. The full report walks through each state’s daily price chart, the ASX Energy CY27 and CY28 base swap table, the renewable record events, and the 90-day fuel mix.