Solar holds midday down; the 8 PM-9 PM net-load ramp is the test

Three developments frame today's operating day. The forecast gross-load peak eased 2,403 MW since the prior issue to 87,021 MW at 4 PM CDT, a level still high against 90 days of realized peaks. MetisCast's evening P50 path sits $14.6/MWh above the cleared day-ahead curve at 7 PM CDT, versus a $2.3/MWh average gap across 17 joined hours. South Hub's $4.1/MWh RT-DA premium is mostly the systemwide $2.9/MWh convergence spread, leaving a $1.2/MWh local residual inside its own band, not a location-specific move.

Watch tonight: the net-load ramp into 8 PM CDT, forecast at 11,423 MW/h, the steepest one-hour move in 90 days of history; the cross-location RT-DA spread holding inside -$9.7/MWh to $8.7/MWh; and realized load staying within 2,277 MW of today's forecast vintage.

Yesterday's real-time prices crested in a tight evening window across the hub complex. North Hub posted the day's highest hourly mean at $86.7/MWh at 8 PM CDT, with Houston at $67.5/MWh, ERCOT Hub Average at $62.6/MWh, South Hub at $56.2/MWh, and West Hub at $46.9/MWh at 7 PM CDT.

Day-ahead awards for the same day cleared well below those real-time prints, topping out between $37.2/MWh at South Hub and $41/MWh at North Hub, with Houston at $39/MWh and West Hub at $37.4/MWh, all landing between 8 PM and 10 PM CDT.

Today's remaining-day cleared day-ahead curve prices the same evening transition, with peaks spread across a three-hour band: ERCOT Hub Average tops out at $39.1/MWh at 8 PM CDT, North Hub at $42.8/MWh at 8 PM CDT, Houston at $41/MWh at 7 PM CDT, West Hub at $39.6/MWh at 9 PM CDT, and South Hub at $37.4/MWh at 9 PM CDT.

Since the prior issue, West Hub's cleared curve and its day-ahead award both firmed, and South Hub's cleared curve firmed as well, with every hub's peak still resolving inside that 7 PM to 9 PM CDT band. That window lines up with the evening net-load ramp already set as today's decision window; the open question here is the level the market has priced into it, not the hour.

MetisCast's own path for ERCOT Hub Average disputes that level. Its P50 crests at $44.6/MWh at 7 PM CDT, an hour ahead of the cleared curve's $39.1/MWh peak, a $14.6/MWh gap that is the widest of the 17 joined hours against a $2.3/MWh mean divergence across the full vintage, with the model's P10-P90 band widening to $66.6/MWh at that same 7 PM CDT hour.

Tonight's real-time settlement decides which side of that gap holds: if the cross-location RT-DA spread breaks above $8.7/MWh, the cleared curve underpriced the peak; if it holds inside the -$9.7/MWh to $8.7/MWh band that frames the decision window, the day-ahead award stands as the better read of tonight's peak.

MetisCast prices ERCOT Hub Average +$2.3/MWh against the cleared day-ahead curve across 17 joined hours. Its P50 tops out at $44.6/MWh at Aug 14, 7 PM CDT while the market cleared $39.1/MWh at Aug 14, 8 PM CDT. The two agree on when the evening matters and disagree on what it pays.

South Hub's RT-DA premium is largely ERCOT's own convergence spread showing up locally. The ERCOT Hub Average's real-time premium over day-ahead averaged $2.9/MWh across 24 joined hours, a component shared by North Hub ($0.8/MWh), West Hub ($3.1/MWh), Houston ($3.6/MWh), and South Hub, the widest at $4.1/MWh.

Net of that systemwide piece, South Hub's local residual is $1.22/MWh, a middling reading against its own history, and no hub breaks its own residual threshold: none is separating from the system.

The one real dispersion is timing: West Hub's real-time price peaked an hour early, at Aug 13, 7 PM CDT ($46.9/MWh), while ERCOT Hub Average, North, South, and Houston all crested at 8 PM CDT. North Hub set the day's highest hub print, $86.7/MWh, above Houston's $67.5/MWh and South Hub's $56.2/MWh that same hour.

Outage capacity in effect at the cutoff sits at 9,788 MW, the 34th percentile of the trailing 90 days for this hour and weekday, a mid-pack reading rather than a stress signal, and still set to climb toward a 9,801 MW high later in the published vintage. Capacity net of load and the ancillary-service requirement, a narrower quantity that excludes imports and the largest single contingency, reads 8,029 MW at the evening peak hour, the widest such margin in the trailing 90 days; call that headroom, not a scarcity finding, absent aligned reserve, PRC and contingency data.

Seven forced-extension or maintenance outage events remain open in the fleet tonight. ERCOT confirmed no sudden large generation loss on Aug 13, and the operator is running from its primary control center as of early this morning after working from the alternate site the prior afternoon. None of these items shows up as a price driver in today's cleared curve or the overnight real-time prints. 8 sourcesSources for this statementGrid event: WAP_WAP_G6 Forced ExtensionERCOTGrid event: SCES_UNIT1 Forced ExtensionERCOTGrid event: PAD3_ESS_ESR3 Maintenance Level 1ERCOTGrid event: PINN_SLR_UNIT1 Maintenance Level 2ERCOTGrid event: CST1_SLR_SOLAR1 Forced ExtensionERCOTGrid event: NEDIN_NEDIN_G2 Forced ExtensionERCOTGrid event: B_DAVIS_B_DAVIG1 Forced ExtensionERCOTGrid event: Operational InformationERCOT

Two items belong on the forward watch list rather than today's tape. ERCOT froze its interconnection queue, with 2026 data-center submissions reaching 235,888 MW, a regulatory ceiling on load growth beyond this operating day. The August wildfire outlook separately flags above-normal fire risk across ERCOT and the southern Plains from heat and dryness, a transmission risk to track into tonight's ramp, not a factor behind today's cleared prices. 2 sourcesSources for this statementData Center Backlash Widens as Texas Freezes 474 GW Grid Queuenaturalgasintel.com · 2026-08-12T00:00:00.000ZAugust Wildfire Outlook Expands Risk Across U.S. Energy Regionsindustrialinfo.com · 2026-08-10T00:00:00.000Z

North Hub produced the day's highest real-time print at $86.7/MWh on Aug 13, 8 PM CDT, well above the other three hubs at that hour, yet its 24-hour RT-DA mean is only $0.8/MWh, a $2.9/MWh system component offset by a $2.11/MWh negative local residual, inside North's own $5.3/MWh residual threshold.

Houston Hub's real-time price sits at the 13th percentile of its trailing 24 hours and the 10th percentile of its trailing 30 days, soft versus its own recent range even as it carries the highest mean level among the four hubs. Desk attention belongs on North Hub's chart in the hub-detail grid: a break above $5.3/MWh in its own residual, independent of the systemwide band, would mark a location separating rather than the system moving.

Forecast-vintage policy. Every input in this issue was published at or before the knowledge cutoff. Forecast series are the latest vintage available at that instant and are never revised after the fact; realized history used for percentiles is guarded by the same cutoff. The preceding issue's frozen vintage is stored with the issue, so a revision is measured against what was actually published, not against a later correction. This issue could not close 3 analytical gaps: residual dispatchable demand, reserve, prc and contingency coverage, weather-to-market translation. Each is stated in the analysis rather than filled in by inference.

Source and quality note. 29 of 29 requested issue series were available; 16 longer-lookback series supported deterministic context. 13 event records were known at cutoff and 2 unchanged records were suppressed. Knowledge cutoff: Aug 14, 8:00 AM CDT.