Real-Time Blew Past Yesterday's Day-Ahead Call; Tonight Prices Another Spike
Thursday, Oct 8, 2026 · ERCOT data as of 8:00 AM CDT
Issue of Oct 8 · generated 8:21 AM CTLatest
Real-time blew past yesterday's day-ahead call at the evening peak, consistent with falling physical reserves.
- Tonight's curve prices ERCOT Hub Average at $153.60/MWh, the highest of its trailing 30 daily cleared peaks, though the curve has missed recently.
What changed since the last issue#
Yesterday's 6 PM-9 PM CDT watch resolved as blowout, not fade: real time ran 1.4 times above the day-ahead range at Oct 7, 7 PM CDT, consistent with physical reserves falling from 17,735 MW to 9,660 MW in three hours. The premium peaked at $82.53/MWh at West Hub, then reversed to a -$45.85/MWh discount for the hub average by 9 PM CDT.
Notable readings
- West Hub real-time peakusual $55.46 to $139.21/MWh · Oct 7, 7 PM CDT
- $255.55/MWh
- South Hub real-time averageusual $26.76 to $45.99/MWh · Oct 7 to Oct 8
- $64.40/MWh
- South Hub real-time peakusual $47.45 to $119.36/MWh · Oct 7, 7 PM CDT
- $209.72/MWh
- ERCOT Hub Average real-time averageusual $28.07 to $51.55/MWh · Oct 7 to Oct 8
- $64.37/MWh
Real-time overshot day-ahead by 1.4x as reserves fell at the peak#
All four hubs converged on a single peak hour, Oct 7, 7 PM CDT, when ERCOT Hub Average reached $224.90/MWh, ranking at the 93rd percentile of its trailing 30 daily peaks; that spike is consistent with physical reserves dropping from 17,735 MW to 9,660 MW within three hours.
A net-load ramp of 4,798 MW into the hour and wind running 38.6% below the forecast published before day-ahead close are contributing factors alongside the reserve decline. A positive system load forecast miss is ruled out: system-wide actual load ran 1,023 to 1,427 MW below both the forecast published before day-ahead close and the latest forecast published before the hour.
| Location | Hour | Real time over day-ahead | Typical hub | Beyond the typical hub | Usual hourly range | Reading |
|---|---|---|---|---|---|---|
| North Hub | Oct 8, 7:00 AM CDT | -$8.5/MWh | -$9.4/MWh | $0.9/MWh | $6/MWh | Within its usual range |
| South Hub | Oct 8, 7:00 AM CDT | -$9.2/MWh | -$9.4/MWh | $0.2/MWh | $8.5/MWh | Within its usual range |
| West Hub | Oct 8, 7:00 AM CDT | -$14.7/MWh | -$9.4/MWh | -$5.3/MWh | $7.1/MWh | Within its usual range |
| Houston Hub | Oct 8, 7:00 AM CDT | -$9.6/MWh | -$9.4/MWh | -$0.2/MWh | $6.7/MWh | Within its usual range |
Tonight's curve prices the highest peak in 30 trailing days; model runs lower#
Tonight's cleared day-ahead award for ERCOT Hub Average lands at $153.60/MWh for the 8 PM CDT hour, sitting above every one of its trailing 30 cleared peaks and well outside its usual $53.01 to $100.04/MWh range. Net load is set to ramp 12,617 MW/h into 7 PM CDT, with forecast generation outages running 21,583 MW. The house model prices the same 16 hours $8.60/MWh below the curve on average, with its widest gap $71/MWh at 9 PM CDT.
What to watch today#
- South Hub beyond $8.5/MWh over the typical hub between 4 PM and 10 PM CDT would flag a new local dislocation, not last night's system move.
- ERCOT Hub Average's real-time-minus-day-ahead spread averaging above $9.3/MWh across 4 PM-10 PM CDT would mean tonight ran hotter than the curve prices.
- System demand topping 77,447 MW at Oct 8, 5 PM CDT would cross a chosen monitoring threshold above the cutoff's forecast peak.
- West Hub real-time averaging above $139.21/MWh between 6 PM and 9 PM CDT would mark a new breach of its usual range tonight.
Ask the agent
The agent answers from this issue and checks the live data.
Sources and web research
Web research: Completed for this issue; it did not add a source-backed explanation beyond the grid, operator, and regulatory evidence cited below.
- National Digital Forecast Database maximum-temperature forecast · NOAA/NWS · Official historical WMS rendering valid 2026-10-09T00:00:00.000Z UTC. The exact PNG bytes and source request were archived with this issue.
11 Ask the Grid datasets, frozen at the issue cutoff
- Dataset: ercot.lmp_by_settlement_point · Ask the Grid data catalog · Supports ERCOT Hub Average real-time price, North Hub real-time price, South Hub real-time price, West Hub real-time price, Houston Hub real-time price in this issue.
- Dataset: ercot.spp_day_ahead_hourly · Ask the Grid data catalog · Supports ERCOT Hub Average day-ahead price, ERCOT Hub Average cleared day-ahead price, North Hub day-ahead price, North Hub cleared day-ahead price, South Hub day-ahead price, South Hub cleared day-ahead price, West Hub day-ahead price, West Hub cleared day-ahead price, Houston Hub day-ahead price, Houston Hub cleared day-ahead price in this issue.
- Dataset: ercot.system_load · Ask the Grid data catalog · Supports ERCOT system demand in this issue.
- Dataset: ercot.load_forecast · Ask the Grid data catalog · Supports ERCOT system load forecast in this issue.
- Dataset: ercot.supply_demand · Ask the Grid data catalog · Supports ERCOT committed capacity, ERCOT capacity forecast in this issue.
- Dataset: ercot.sced_system_lambda · Ask the Grid data catalog · Supports ERCOT SCED system lambda in this issue.
- Dataset: ercot.hourly_resource_outage_capacity · Ask the Grid data catalog · Supports ERCOT forecast generation outage capacity in this issue.
- Dataset: ercot.hourly_ruc_committed_capacity · Ask the Grid data catalog · Supports ERCOT RUC committed capacity in this issue.
- Dataset: ercot.shadow_prices_sced · Ask the Grid data catalog · Supports ERCOT binding constraint count, ERCOT maximum absolute constraint shadow price in this issue.
- Additional Ask the Grid market series · Ask the Grid · ERCOT battery fleet net output, ERCOT wind generation, ERCOT wind forecast, ERCOT solar generation, ERCOT solar forecast, as published at the issue cutoff and kept with this issue.
- Metis 1 Preview nodal price ERCOT Hub Average probabilistic price forecast · Ask the Grid · Forecast issued Oct 8, 7:30 AM CDT, version L20260916b. The low-end, middle and high-end forecasts are averages of the model's intervals within each complete hour.
Written by the grid agent from 29 market series, and checked against them before it was sent. All requested series were fetched.
All issues
| Issue | Generated | |
|---|---|---|
| Oct 7 to Oct 8, 2026Reading | Oct 8, 2026 | |
| Oct 6 to Oct 7, 2026 | Oct 7, 2026 | |
| Oct 5 to Oct 6, 2026 | Oct 6, 2026 | |
| Oct 4 to Oct 5, 2026 | Oct 5, 2026 | |
| Oct 3 to Oct 4, 2026 | Oct 4, 2026 |