Soft September LMPs, Hard Large-Load Queues
On 26 September 2026, ERCOT’s system peak still looked like late summer: Eden Energy’s prior-day recap puts actual load near 78.5 GW in hour ending 17, with Dallas, Austin, and San Antonio in the mid-90s°F and Houston near 90°F. Net load rose into the evening as solar declined – the classic ramp shape. What did not appear was a scarcity-style spike. Hub-average day-ahead locational marginal prices (LMPs) averaged about $32.96/MWh; real-time averaged about $26.16/MWh, for a day-ahead-minus-real-time (DART) spread near +$6.80/MWh.
The strongest real-time hour in that recap was HE 19 at roughly $37.52/MWh – moderate relative to ERCOT’s historical scarcity hours, consistent with renewables plus dispatchable generation covering the ramp without reserve emergency pricing. In parallel with soft LMPs, ERCOT’s large-load process remains constrained by the Batch Zero verification and audit path under Planning Guide Revision Request (PGRR) 145. Provisional Batch Zero classifications (base, studied, excluded) went to interconnecting transmission service providers around 3 September 2026.
ERCOT briefings in that docket also cite an illustrative near-term stack: on the order of 17 large-load data center/crypto projects totaling about 6,608 MW of peak demand over five years that have finished ERCOT processes except approval to energize – figures that belong in planning dashboards, not in a claim that 6.6 GW is already consuming. When megawatts sit just short of energization, commercial offtakers and generators still price option value on future peak coincidence, congestion, and ancillary needs.
That forward premium can coexist with $26–$33 hub averages for three independent reasons: Developers who read only the September energy tape may underbid hedges and on-site flexibility. Capacity at the collar can stay elevated while energy markets print unremarkable shoulder-season LMPs – exactly the split large loads care about when they buy “power” as a bundled retail product. The last days of September 2026 offered a clean price-tape lesson: ERCOT can look cheap on energy while large-load interconnection remains administratively expensive.