Prometheus Targets 2027 Power on 2.5 GW Istmo Dual-Fuel Outside ERCOT

Prometheus Hyperscale and Istmo Energy are advancing a 2.5 GW behind-the-meter data center campus in Pecos, Reeves County, with Phase 1 at 1.5 GW and first power targeted for 2027. Dual-fuel supply from Istmo’s co-located fractionation facility feeds piped natural gas and ethane straight to the campus, so the project never enters the ERCOT interconnection queue.

Closed-loop cooling is the stated water design, and the sponsors frame islanded power as insulation from Governor Greg Abbott’s large-load audit and from ratepayer scrutiny. Prometheus is also planning a 500-acre Kaufman County site and a Wyoming islanded campus that starts at 1.25 GW.

Governor Josh Shapiro signed Executive Order 2026-05 on August 18, pulling AI data center proposals out of Pennsylvania’s Fast Track program, banning developer NDAs, and requiring local approval plus full cost responsibility for generation, transmission, distribution, water conservation, and annual energy and water reporting before DEP will process permits. Pennsylvania still shows 100+ proposed projects, with only five holding all first-phase permits.

Electoral pressure is rising elsewhere. The NRSC flagged data centers as a midterm “sleeper issue”; Rep. Byron Donalds used ratepayer-protection framing in Florida’s gubernatorial primary; former Sen. Sherrod Brown has centered Ohio opposition against a Pike County build where OpenAI has secured 8 GW of a 10 GW campus. In Minnesota, MCEA CEO Kathryn Hoffman is hitting NDA-driven opacity around hyperscale load and water, with Hermantown’s Google proposal already in dual litigation over environmental review and zoning.

Schaper Energy Consulting LLC filed Aug. 20 in PUCT Control No. 59142 (Item 54), backing ERCOT’s electrical maturity tests but warning that end-stage community-impact gates on site development, real estate, contracts, and local-authority calls sit outside ERCOT’s objective standards. Schaper says disputes with TSPs and interconnecting large loads will “ultimately require resolution by the courts,” and it disputes ERCOT’s Aug. 20 claim that it has capacity to process an expanded audit while Batch Zero attestations remain uncleared.

At an Aug. 19 House State Affairs hearing chaired by Rep. Ken King, R-Canadian, ERCOT President and CEO Pablo Vegas said ERCOT will audit roughly 200 GW of pending large-load proposals (facilities expecting at least 25 MW) and finish by late November or early December, then launch the batch study on demand, interconnection cost, and transmission buildout. Audit findings are expected to reach the PUC, TWDB, TCEQ, and lawmakers by year-end; operators that can’t document water offsets, self-supplied power, ratepayer protection, and neighborhood coexistence before that handoff carry schedule and posted-capital risk through the next study cycle.

Bottom line: lock verifiable maturity evidence now, and demand written criteria and timelines before more deposit capital sits behind subjective gates.

Reeves County’s dual-fuel design is the clearest Texas proof point that self-supplied power is how operators convert midstream adjacency into energization dates the queue can’t match. Phase sequencing through 2027, with optional custom facilities in 2028, keeps capital tied to demand instead of a single COD bet.

Fuel-path and air-permit sequencing still sit on the critical path, and community pushback on large on-site generation is already campaign material in other states. Turbine scarcity is pushing some sponsors toward whatever iron is available, which tightens both schedule and local narrative risk.

Bottom line: treat private generation as a full development workstream with fuel contracts, TCEQ air timing, and county engagement running in parallel with the building pad.

Texas still can’t inventory datacenter water. TCEQ deputy water-quality director Robert Sadlier told the House panel TCEQ doesn’t require water-consumption disclosure on datacenter permit applications; TWDB water supply director Temple McKinnon said the board only surveys existing sites, not the proposed pipeline. PUC responses cover just 28 companies and fewer than 100 facilities; TWDB’s separate survey sits at a 29% response rate and still skips proposed load.

In the Permian, nearly 1 billion gallons a day of oilfield produced water is still going to injection wells that are running out of capacity. Railroad Commission Commissioner Jim Wright urged TCEQ to finalize workable discharge and rangeland permits; TCEQ holds EPA primacy and has accepted river-discharge applications since 2024 but has issued none, while a land-application rule remains proposed. Closed-loop claims without county water-district sign-off, including at Reeves County Water Control and Improvement District 1, are the near-term permit friction.

Bottom line: file water offsets, reuse, or alternate supply before the year-end audit package, or budget carrying cost while agencies write the standards your silence left blank.