AEMO forecast shows 2,328MW NSW demand drop for Monday (2026-06-22) afternoon as NEM-wide low wind stretches to second day
A sharp intraday demand forecast swing in New South Wales compounds a two-day wind drought across the National Electricity Market.
AEMO's target demand forecast for New South Wales showed a 2,328MW drop for the period ending 16:25 on Monday (2026-06-22), a steep intraday decline arriving during the second consecutive day of suppressed wind output across the NEM. Low wind yield was recorded through Sunday (2026-06-21) into Monday (2026-06-22), as documented in WattClarity's pre-configured Trends Engine query from ez2view.5
A demand swing of that magnitude in a single afternoon window forces AEMO to lean harder on dispatchable capacity and interconnector flows. The target demand figure is what AEMO instructs the market to meet after adjusting for rooftop solar, battery charging and other distributed resources, so a drop of this size signals something significant shifting on the supply-demand balance.5
The low wind period that began Sunday (2026-06-21) is not unusual for June, but its timing compounds the operational challenge. Winter mornings in the NEM typically carry high demand for heating while solar output ramps slowly. When wind drops simultaneously, the gap falls on gas, coal, batteries and imports from neighbouring regions.5
NSW's remaining coal fleet carries much of the baseload, and any unplanned outage during a period of low wind leaves thinner headroom than traders might price in. The state's grid fragility under stress has precedent: politicians waited until noon on Wednesday (2024-11-27) to plead with households to throttle electricity use to keep NSW through spring without rolling blackouts, with AEMO's summer readiness media statement delayed that week because operators were managing the grid through the period.4
AEMO's forecasting accuracy is a live issue for the market. On Monday (2026-05-11), the operator released a Reviewable Operating Incident Report detailing how a self-forecast vendor glitch contributed to a frequency excursion on 19 August 2025. Market participants have since scrutinised AEMO's published target demand outputs more closely for anomalies, and the 2,328MW NSW swing will draw the same attention.1
The 16:25 period is operationally awkward because solar output is already fading by that hour, meaning the system loses two generation sources at once when wind is simultaneously weak. Traders watching the afternoon window on Monday (2026-06-22) would have been tracking whether actual dispatch outcomes matched the forecast and whether interconnector flows from Victoria and Queensland absorbed the gap.5
Longer-term NEM planning sets the context for why single-day wind events carry weight. AEMO's base case fleet projection reaches 50GW of wind, 49GW of solar and 45GW of batteries alongside about 10GW of gas. A high-cost-of-capital sensitivity scenario builds 62GW of batteries but only 7GW of gas.2 Under the base case, gas retains a meaningful backstop role during extended low-wind periods. Under the cost-stressed scenario, batteries must carry multi-day wind droughts — exactly the kind of event the NEM saw across Sunday (2026-06-21) and Monday (2026-06-22). June's low wind events are precisely the test that batteries can fail if state-of-charge entering the event is insufficient.2
Demand-side complexity is growing faster than the fleet transition. AEMO's CEO told Australian Energy Week on Thursday (2026-06-11) that average data centre demand through the first quarter of 2026 in the NEM was nearly 600MW, with 11 data centres totalling 5.4GW of ultimate load working through transmission connection queues.3 Those loads do not flex with the grid the way households can be asked to curtail. They run flat, narrowing the operator's tolerance for forecasting error.
The August 2025 frequency incident remains the reference point for what goes wrong when forecasting errors compound with physical stress. AEMO's incident report showed how the vendor glitch fed bad self-forecasts into the system, and the resulting excursion took time to correct. Generators and retailers holding spot-market exposure face real cost if a similar failure mode recurs during a period of low wind and fading solar.1
The unresolved question from Monday (2026-06-22) is whether evening demand — after solar has fully dropped off and wind remained weak — pushed AEMO into further forecast revisions and whether any interconnector constraints emerged. If wind stayed low through the evening peak, every available megawatt from gas and storage would have been in play. How the operator's actual dispatch tracked against its published forecasts will be visible in the market data and is worth examining against the August 2025 incident as a baseline.5,1