Summary

  • Montana, North Dakota and New Mexico filings describe Crusoe engines running on gas their applications call otherwise-flared — named machines, per-engine limits, one pad at a time.
  • None of those documents quantifies the flare displaced. The 220,000-tonne avoidance figure is a 2022 company model, and the proposed Longhorn campus in Texas runs on pipeline-quality gas instead.

Anyone comparing AI capacity on its emissions line is comparing numbers made by different machines, in different accounting frames, under assumptions chosen by different parties. The operator behind one of the louder claims in that comparison spent its early years bolting reciprocating engines onto oil wells so that gas coming off the separator burned inside an engine instead of at the tip of a flare. Regulators wrote that arrangement down, unit by unit, at named facilities. What they did not write down is how much flaring went away.

That gap is the whole argument, and it is narrower than the marketing that grew out of it. The permits are real. The displacement is real in the sense that a regulator accepted the description and issued limits for equipment that would consume the gas. But the headline climate figure — more than 220,000 metric tons of CO2-equivalent avoided — is not a permit finding. It is a model the company published itself, and it rests on two parameter choices any buyer of that capacity should be able to name.

The fleet has also left the premise behind. The 2024 Texas filing for the Longhorn Data Center near Abilene describes twelve 35-megawatt simple-cycle turbines fed by pipeline-quality natural gas, a fuel with no flare to displace at all. Twelve units at 35 MW each is 420 MW of proposed capacity. The first Crusoe sites were permitted at two engines apiece.

Two engines, three mentioned

Montana's Department of Environmental Quality issued Air Quality Permit #5317-00 to Crusoe Energy Systems for the Shirley facility, header dated 6 December 2024 (Montana DEQ #5317-00). It authorises up to two Waukesha 9394 GSI engines, each rated at no more than 2,500 brake horsepower — the shaft output a regulator uses as the denominator for per-engine limits — with air-fuel-ratio control and non-selective catalytic reduction, a catalyst that converts nitrogen oxides into nitrogen and water.

The fuel sentence is the one the business rests on: field gas that "would otherwise be sent to a process flare for combustion". The per-engine ceilings are 0.83 pounds per hour or 0.15 grams per brake-horsepower-hour of NOx, 1.65 lb/hr or 0.30 g/bhp-hr of carbon monoxide, and 0.17 lb/hr or 0.03 g/bhp-hr of volatile organic compounds.

The greenhouse-gas section does not do the work the pitch needs. It assesses what the generators emit; it does not quantify what the flare would have emitted. It also refers to three engines while authorising two, and its tonnages disagree with each other by orders of magnitude — one line gives 23.41 metric tons CO2e per year beside totals in the thousands. Those figures are internally inconsistent, so they are not used here for either side of the comparison.

The site has changed hands since. Permit #5317-02, issued 11 November 2025 to NYDIG DFM, LLC for the same Shirley facility, records the transfer from Crusoe, the replacement of #5317-00 by #5317-01, and of #5317-01 by #5317-02 (Montana DEQ #5317-02). The successor keeps the two 2,500-brake-horsepower Waukesha engines and is classed as a true-minor source — emissions below the thresholds without a taken limit, as against a synthetic minor, which accepts an enforceable cap to stay under them — so the annual synthetic-minor certification goes away. A displacement arrangement that outlives its originator as an equipment schedule tells you something about how much of the claim was ever attached to the company rather than to the pad.

Fort Berthold, where EPA wrote the permits

EPA Region 8 keeps a register of the Clean Air Act permits it issues. It lists Charging Eagle 21-25 as TMNSR-TAT-008173-2022.001, a true-minor source issued 29 August 2022, and Crosby Chase CTB as SMNSR-TAT-008149-2023.002, a synthetic-minor revision issued 9 February 2024 (EPA Region 8 permit register). Both sit on Fort Berthold Indian Reservation land in North Dakota, which is why a federal agency rather than the state did the permitting.

The Charging Eagle application states the purpose plainly: three 2,500-horsepower Waukesha 9394GSI engines on RimRock's pad, sized to consume production gas otherwise destined for flaring and to power small data centres (Charging Eagle application). Crusoe also asked the agency to treat its generator set as a source separate from the oil-and-gas operator next door. That boundary matters, because without it the engines would be counted inside the operator's potential to emit.

The air quality impact analysis filed alongside is the closest this record comes to the comparison (Charging Eagle analysis). It assigns 0.42 pounds per hour of NOx to the tank flare and 0.59 to the gas flare, and gives those flares heat release of 3.95 and 6.55 million British thermal units per hour — a rate of heat, which is what MMBtu/hr measures. The conclusion says the project emits less than business-as-usual flaring. What it does not contain is an annual avoided tonnage or a CO2e calculation. The flare rates are inputs to air-quality modelling, not a measured baseline.

Crosby Chase arrived a different way. EPA's permit page records issue on 9 February 2024 and effect from 11 March 2024, docket EPA-R08-OAR-2023-0443 (Crosby Chase permit page). The agency's 2021 memo to file for the earlier version of the action describes a 484-hp compressor, a 2,500-hp generator and a 13,106-kW turbine running on central-tank-battery gas "that would otherwise be flared" to power small data centres (EPA memo, 2021). The memo weighs air and endangered-species effects, not greenhouse gases, and it calls the same action a true minor in one place and a synthetic minor in another. That inconsistency is in the file.

Twelve engines and a box that does not add up

New Mexico's Gold State modification application 10145M1, dated 24 May 2024, describes five already-permitted Waukesha engines and asks for seven more: twelve 2,500-horsepower units on field gas described as otherwise flared, with catalysts and air-fuel-ratio controls (Gold State application). Table 2-P reports 130,938 short tons of CO2e per year of proposed facility emissions. Emissions, not avoidance. The number counts what the engines put into the air, and in the same table the filing ticks the box for staying below 75,000 tons.

The department's legal notice for agency-interest number 41141 in Lea County restates the twelve-engine total and a proposed figure above 75,000 tons a year, and gives a preliminary intent to issue on or before 27 September 2024 (NMED legal notice). An intended deadline is not an issuance. The signed New Mexico permits are not part of this record, so issued terms for Gold State are not established here.

The number that travels

The only fleet-level figure in the record is the company's own. A Crusoe publication dated 10 November 2022 estimated that nearly 2,700 metric tons of methane would have escaped had the gas it consumed instead been flared, and claimed more than 220,000 metric tons of CO2e avoided (Crusoe GHG article). The comparison assumes 99.91% combustion efficiency in the generator against 91.1% for an open flare, and converts methane at a 20-year global-warming potential of 82.5 — the multiplier that turns a mass of one gas into a CO2-equivalent mass over a chosen horizon. Methane's 20-year multiplier is far larger than its 100-year one.

Three things follow, and none of them is that the number is false. It is a model rather than a measurement, and its two most consequential parameters were chosen by the party making the claim. The 20-year convention is legitimate and is also the one that produces the largest headline. And a permit's CO2e total and an avoided-emissions figure sit in different frames: one measures what an engine emits, the other models what an unperformed flare would have emitted. They do not net, and they are not netted here.

For a capacity buyer the question is not whether the company once did something real. It is whether the arithmetic behind a contract's emissions line survives contact with a site audit. The question is specific enough to ask in a procurement meeting: separate from your permit limits, show the displaced-flare tonnage per site, the combustion-efficiency baselines used, the GWP convention chosen, and whether the campuses now being sold still qualify for the counterfactual at all.

What the Texas filing says about the next fleet

The Longhorn application reached TCEQ on 15 August 2024, sixty pages prepared by Pinyon Environmental, proposing six 35-MW Titan 350 turbines and six 35-MW GE LM2500 turbines, all simple-cycle, meaning exhaust heat is thrown away rather than recovered for extra electricity (Longhorn application). The turbines "will be fueled by pipeline quality natural gas", with selective catalytic reduction and aqueous ammonia injection, more than 300 operating hours a year, and a 0.14 lb/MWh NOx standard. It is an application; final authorisation terms are not established.

The filing contains no avoided-flaring comparison, and none would be coherent. Pipeline gas is bought, metered and burnt; it displaces no flare at a wellhead. This is the point where a fleet-level avoidance claim stops covering the fleet. The premise that made the early sites interesting does not scale with them, because scaling meant buying a different fuel.

What this record contains, and what it does not

There is no Colorado issued permit in it, no signed New Mexico permit, and no final Texas authorisation. That leaves a documented equipment class, documented limits, a documented fuel description, and not one regulator-computed displaced-flare figure. Site-level avoided tonnage and permitted emissions are different quantities, and the first is the one no inspected document supplies.

The Crusoe Energy Systems LLC record is the corporate identity under examination here. Earlier BTW reporting covered the financing, the gigawatt campuses, the engine order and the two-Crusoe name collision in the ARIN address book. None of it asked what the fuel was. The answer is that the fuel changed and the sentence did not.