The last seven days of detected price spikes, negative pricing intervals, record renewables and binding grid constraints across the NEM and WEM. 17 Aug 2026 to 24 Aug 2026.
South Australia (SA1) experienced high renewable penetration of 95.4% during the evening of 23 August 2026, driven predominantly by wind generation of 968.59 MW alongside battery output of 207.1 MW combined. Regional prices exhibited high volatility during this period, with rapid fluctuations between $55.68/MWh and $156.10/MWh across five-minute settlement intervals.
A binding constraint (T_BLINK_TV_NGZ) in TAS1 reached an exceptionally high shadow price of $8.35 million, indicating severe scarcity or transmission limitations affecting the region during the 21:20–21:50 settlement period on 23 August 2026. Regional spot prices ranged between $34–$52/MWh during this interval, with Tasmanian generation comprising approximately 1,200–1,300 MW of hydro and 290–360 MW of wind across the snapshot period.
Tasmania experienced a major constraint event on 23 August 2026 with binding constraint T_BLINK_TV_NGZ reaching an extremely high shadow price of $8.352 million, whilst regional prices remained moderate (ranging from $23.69 to $55.12/MWh). The constraint binding coincided with substantial hydro and wind generation across multiple settlement intervals, with total available renewable capacity exceeding 2,600 MW.
Tasmania achieved 100% renewable generation during the early morning period of 23 August 2026, with hydro, wind, and rooftop solar providing all generation capacity. Regional reference prices exhibited significant volatility, ranging from −$2.96/MWh to $64.20/MWh across the six consecutive five-minute settlement periods, suggesting rapid changes in system conditions or constraints.
South Australia (SA1) experienced sustained negative pricing during the early morning period of 23 August 2026, with two intervals recording prices around −$3/MWh. The negative pricing occurred against a background of high renewable generation, particularly solar (278–230 MW) and wind (169 MW) output, combined with moderate gas generation.
VIC1 experienced sustained negative pricing during the 05:45–06:20 interval on 23 August 2026, with prices reaching −$3.87/MWh and −$3.50/MWh across two intervals. The negative pricing occurred amid high renewable generation (wind and solar totalling approximately 1,669 MW) and substantial brown coal baseload (3,260 MW), creating oversupply conditions in the region.
QLD1 experienced sustained negative pricing across three consecutive intervals on 23 August 2026 from 02:50 to 03:20, with the minimum price reaching −$8.51/MWh. The event occurred during early morning hours with high solar generation (approximately 1,728–1,897 MW) combined with substantial coal-fired output (3,259 MW), creating an oversupply condition in the region.
TAS1 experienced sustained negative pricing at approximately −$4.62/MWh across two consecutive intervals (00:20 and 00:25 on 23 August 2026). This minor event occurred during a period of elevated renewable generation, with combined hydro and wind output exceeding 900 MW alongside rooftop PV contribution.
SA1 experienced sustained negative pricing of -$4.04/MWh during the 00:20 settlement interval on 23 August 2026, following a price dip to -$1.10/MWh in the preceding interval. The negative pricing occurred during a period of high renewable generation, with wind contributing 663.49 MW and solar contributing 330.05 MW to the regional supply mix.
VIC1 experienced sustained negative pricing with a minimum of −$4.67/MWh across two consecutive intervals (00:15 and 00:20 on 23 August 2026). Prices briefly dipped into negative territory before returning to positive levels, indicating a localised oversupply condition in the region.
South Australia (SA1) experienced high renewable energy penetration of 93.1%, driven predominantly by wind generation at 976.52 MW, with solar contributing 179.28 MW across the region. Regional spot prices remained relatively modest, ranging from $12.42 to $23.24/MWh across the five settlement periods shown, reflecting the abundant renewable supply.
QLD1 experienced sustained negative pricing at −$1.92/MWh across 2 intervals on 22 August 2026 at 21:25 and 21:35, following a sharp price collapse from $56.83/MWh earlier in the evening. The region's generation mix was dominated by coal (4,652.6 MW) and solar (1,752.6 MW combined), with wind contributing 763.52 MW, creating a substantial supply surplus relative to demand.
The WEM in Western Australia experienced a moderate price spike to $261.13/MWh in the 13:35 trading interval on 22 August 2026, representing a sharp increase from the preceding $146–151/MWh range. This single-interval spike occurred within a generation mix dominated by gas-fired plant (1,290 MW combined CCGT and OCGT) alongside substantial wind generation (353 MW).
Tasmania achieved 100% renewable energy penetration on 22 August 2026, with hydro and wind generation totalling approximately 2,062 MW across the settlement period. Despite high renewable supply, spot prices rose sharply from $24.09/MWh to $75.90/MWh over the five-minute intervals, indicating tightening system conditions rather than oversupply.
VIC1 experienced sustained negative pricing at $-0.10/MWh across two consecutive intervals (02:55 and 03:05 on 2026-08-22), representing minor negative price events. Prices declined sharply from $5.43/MWh at 02:40 to negative territory, with the region then recovering to slightly positive pricing shortly after.
NSW1 experienced minor negative pricing with a floor of –$0.11/MWh across two intervals on 22 August 2026 at 02:50–03:05 UTC, following a period of volatile pricing between $29.83 and $1.51/MWh. The negative pricing episodes were preceded by a sharp decline in regional spot prices, suggesting oversupply conditions in the overnight period.
TAS1 experienced sustained negative pricing at approximately $-0.05 to $-0.10/MWh across two consecutive intervals (03:05–03:10) on 22 August 2026. The event occurred during the early morning low-demand period with high renewable generation from wind (334–465 MW) and hydro (261–317 MW) sources.
A severe binding constraint (F_T+LREG_0050) emerged in the NEM with an exceptionally high shadow price of $232,000/MWh, indicating significant market scarcity and dispatch inflexibility. This constraint was the dominant binding limitation in the dispatch interval, substantially limiting power flow and creating substantial uplift costs for market participants.
A high-value binding constraint (F_T+NIL_ML_RECL_L6) with a shadow price of $2,944/MWh emerged in the NEM, significantly restricting dispatch flexibility. This constraint dominated the market pricing signal, with all other active binding constraints carrying substantially lower marginal values (under $9/MWh).
A binding constraint with an exceptionally high shadow price of $8.352 million was active in TAS1 during the 21 August 2026 morning period, coinciding with modest regional electricity prices in the $31–$48 range. The constraint remained binding across multiple consecutive settlement intervals whilst Tasmania's generation mix comprised substantial hydro and wind capacity with no gas-fired generation online.
SA1 experienced a moderate price spike reaching $375.79/MWh during the 08:35 interval on 21 August 2026, with prices remaining elevated at $375/MWh in the following interval before declining sharply to $130/MWh. This represented a sharp 2.4× increase from the preceding baseline of approximately $156/MWh.
Tasmania experienced 100% renewable energy penetration on 21 August 2026 during the early morning period, with hydroelectric and wind generation meeting all demand. Regional reference prices rose from $36.19/MWh to a peak of $60.16/MWh across the five-minute settlement intervals, despite the absence of thermal generation.
A high-severity binding constraint (T_BLINK_TV_NGZ) in TAS1 reached an extreme shadow price of $8.352 million, coinciding with a sharp spot price increase from $30.18/MWh to $90.42/MWh in the 00:05 settlement period on 21 August 2026. Tasmania's generation mix remained dominated by hydro (955–1226 MW) and wind (369–430 MW) throughout the event window.
QLD1 experienced sustained negative pricing of approximately −$3.73/MWh during the 23:00–23:05 UTC interval on 20 August 2026, following a brief period of near-zero or low positive prices. The negative pricing occurred during evening peak solar generation (~2,900 MW) combined with steady coal output (~3,140 MW), suggesting an oversupply condition in the region.
Tasmania achieved 100% renewable penetration during the 06:05–06:30 UTC period on 20 August 2026, with hydro and wind generation totalling approximately 1,230–1,450 MW across multiple snapshots. Prices ranged from $36.21–$54.95/MWh, with a spike to $54.95/MWh at 06:20 UTC followed by moderation.
SA1 experienced sustained negative pricing at −$1.10/MWh during the 03:25 interval on 20 August 2026, with a second interval at −$0.38/MWh immediately preceding it. This minor event occurred during a period of high renewable generation, with wind contributing 585 MW and solar 365–399 MW to the region's supply mix.
South Australia (SA1) experienced high renewable penetration of 87.5% during the early morning period of 20 August 2026, driven predominantly by wind generation (410.78 MW) and solar generation (312.54–334.26 MW). Spot prices remained relatively subdued, ranging from $16.12 to $68.51/MWh, with most settlement periods trading in the $20–$45/MWh band.
QLD1 experienced sustained negative pricing at -$1.31/MWh across two consecutive intervals (00:45 and 00:50 on 20 August 2026), following a period of near-zero pricing. The event occurred during a period of very high solar generation (approximately 5,806 MW combined across QLD regions) and moderate wind output (634 MW), with black coal generation at 3,443 MW contributing to oversupply.
A binding constraint (T_BLINK_TV_NGZ) in Tasmania reached an exceptionally high shadow price of $8,352,000/MWh during the 00:10–00:35 period on 20 August 2026, causing significant price volatility with RRP ranging from $40.22 to $88.16/MWh. Tasmania's generation mix remained stable with approximately 900–1,060 MW of hydro and 340–380 MW of wind throughout the event.
Tasmania (TAS1) experienced a moderate price spike with the spot rate rising sharply from A$110.83/MWh to A$374.26/MWh across two consecutive intervals on 19 August 2026, peaking at 23:10 UTC. This represented a 238% increase in pricing within 10 minutes.
Events are detected automatically by gridIQ from AEMO dispatch and constraint data, then enriched with AI-generated causal analysis. For the full searchable archive, see the event history. For deeper context on price spikes and negative pricing, read the negative-price explainer or browse live electricity prices by region.