They share a unit, gigawatts, and nothing else.
Researched by an agentic pipeline. Reviewed and approved by the editor before publication.
If your compute plan depends on a data centre that will make its own power with on-site gas, the most reliable number you have is the smallest one. Cleanview, a US energy-data vendor, tracks 59 behind-the-meter data-centre projects totalling about 90 GW of announced capacity. About 2 GW of that is operating today. That is 2.2% of the total1.
The large numbers that sit next to it — record gas-turbine order books at Siemens Energy and GE Vernova — do not close that gap. Neither manufacturer says how much of its gas order book is for data centres, and neither says how much is for on-site plant rather than grid-connected plant. Orders tell you equipment is being reserved. They do not tell you that a specific campus will be energised on a specific date.
This brief sets out what is running, what is ordered, what limits the conversion from one to the other, and what a planner can reasonably build on.
Cleanview's tracker splits the ~90 GW as follows1:
| Stage | Share of ~90 GW | Basis |
|---|---|---|
| Operating | 2.2% (~2 GW) | Vendor estimate from permits, filings and satellite imagery |
| Under construction | 1.2% | Vendor estimate |
| Permitted | 36% | Permit documents |
| Announced or early-stage | 60% | Announcements and press releases |
The operating figure is concentrated. Cleanview attributes the large majority of the ~2 GW to xAI, and says Colossus 1 and 2 outside Memphis account for 1,498 MW of operating gas-turbine capacity on their own, a fleet that grew as xAI added dozens of temporary mobile turbines1. Remove one developer and the operating record of on-site gas for US data centres is a few hundred megawatts.
Two points about the basis of these numbers matter before anyone plans with them.
First, this is one vendor's tracking. Cleanview says it analysed "hundreds of permit documents, SEC filings, utility filings, and press releases" and used Airbus satellite imagery to check project status1. That is a sound method, but the dataset is not public, the report page carries no publication date, and no regulator or metering record confirms the ~2 GW operating figure. It is an informed estimate, not a measurement of delivered energy.
Second, the denominator is announced capacity. A 60% share that "exists only as announcements or early-stage plans"1 is not a pipeline in the engineering sense. It is a list of intentions. Any ratio built on ~90 GW inherits that softness.
Statewide data points the same way. Global Energy Monitor, as reported by Inside Climate News, counts 81.7 GW of operating gas generation in Texas against 99.4 GW in development and 22.4 GW recently announced, and says the 12 largest planned gas projects in the state are all intended to run data centres9. Those development figures cover all gas generation, not data centres alone, and they are proposals. GEM's own project manager said it is "nearly impossible nowadays to guess what is a pie in the sky proposal, and what has a real chance of getting built"9.
The supply side looks strong, and on its own terms it is.
| Manufacturer | Figure | Basis | Data-centre share disclosed? |
|---|---|---|---|
| Siemens Energy (Q3 FY26) | 73 gas turbines, 15 GW booked | Company-reported via Blockspace; includes reservations converted to orders | No |
| Siemens Energy (Q3 FY26) | Gas Services orders €10bn; backlog €73bn | Company-reported via Blockspace | No |
| GE Vernova (Q2 2026) | 116 GW: 53 GW equipment backlog + 63 GW slot reservations | Company-reported; reservations are not firm orders | No |
Siemens Energy's booking of 73 turbines comprised 25 large and 48 industrial units, which the company put at 15 GW "including customer commitments converted from earlier reservation agreements"3. Those unit and GW figures do not appear in the text of Siemens Energy's own earnings release, which reports a record group order intake of €17.9bn and attributes growth to "a new record order intake at Gas Services" without a turbine count2. On the earnings call, Siemens Energy's chief executive said medium-sized gas turbines "are often selected for distributed power generation and data center applications"3. That is a statement about the suitability of a product, not a disclosure of who bought it.
GE Vernova reported that gas power equipment backlog and slot reservation agreements grew from 100 GW to 116 GW in the quarter, and that it expects at least 125 GW by year-end 20265. Of the 116 GW, 53 GW is equipment backlog and 63 GW is slot reservations67. A slot reservation holds a manufacturing position; it is not a binding equipment order. GE Vernova's widely quoted data-centre figure — more than $5bn of data-centre orders in the first half of 2026, more than double its 2025 total — sits in the context of its Electrification business and, in CompressorTech2's account, includes "grid and electrification equipment"56. It is not a measure of gas turbines sold for on-site data-centre power.
No manufacturer in this record discloses what share of its gas-turbine orders is for data centres, or for behind-the-meter plant. Any claim that turbine order books are supplying the ~90 GW of announced on-site capacity is an inference, not a reported figure.
The two sets of numbers also cannot be added or netted against each other. Cleanview's ~90 GW is announced site capacity across turbines, reciprocating engines and fuel cells; the manufacturers' figures are equipment bookings and reservations for every customer type and every region. They share a unit, gigawatts, and nothing else.
The route from order to energised campus is gated by manufacturing rate, by equipment type, by site work and by permits.
GE Vernova shipped 3 GW of gas turbines in Q2 2026 and says it is moving from roughly 3 GW to 5 GW a quarter from Q3, an annualised rate of 20 GW, with 24 GW targeted for 2028 and 30 GW for 203056. These are targets, not output. Siemens Energy said it shipped 6 GW in the quarter, and that its annual production of medium-sized gas turbines is rising from about 50 units in fiscal 2025 to about 80 in fiscal 2026, with larger expansion contributing from fiscal 202734. Against a 116 GW GE Vernova book alone, a 20 GW annual rate implies years of queue, before any site work begins.
Siemens Energy's chief financial officer said that "across parts of our portfolio, lead times are now three to four years and beyond"4. She did not say this applies to every gas-turbine class, and it should not be read as one.
Equipment choice sets the calendar. GE Vernova's gas power chief said an aeroderivative installation can be commissioned in about six months, while a heavy-duty turbine "may require another 18 months of site work" after leaving the factory6. Cleanview says heavy-duty combined-cycle turbines "have long lead times and are largely unavailable" to these projects1. That is why developers lean on smaller units: Cleanview finds Caterpillar engines and Solar Turbines hold the largest share of tracked projects (33%), with more than 8.8 GW permitted, and Bloom Energy fuel cells 14%1.
The heavy-duty route is opening at the margin. Doosan Enerbility held a ceremony on 6 October 2026 for its first gas-turbine export to the United States — a 380 MW H-class unit for a data-centre and energy project led by SpaceXAI8. That is one unit, and no in-service date has been disclosed.
The write-downs are visible in the record. Cleanview reports that Nebius is struggling to obtain an air permit for a 400 MW on-site gas plant, and that seven of nine compute tranches under its $17.4bn agreement with Microsoft depend on that plant coming online in 20261. In New Mexico, the state blocked a gas pipeline meant to fuel a 2.45 GW on-site plant for a Stargate project; Cleanview's satellite analysis suggests it is likely to miss its 2027 target1. Both accounts come from Cleanview and have not been independently confirmed here.
The only capital-cost figures in the record are estimates. SemiAnalysis puts all-in capital expenditure at $1,700–2,000/kW for both aeroderivative turbines and reciprocating engines, and $1,500–1,800/kW for industrial gas turbines, "at current rates", with no stated source year and a note that costs are "consistently rising"10. No realised contract price for on-site data-centre generation is disclosed. A planner can use these as an order of magnitude; they are not a quoted price.
It establishes that on-site gas for US data centres is, as of mid-2026, overwhelmingly announced rather than running: about 2 GW operating against about 90 GW announced, on one vendor's estimate1. It establishes that gas-turbine order books and reservations are at records, on the manufacturers' own reporting35. It establishes that the conversion from equipment to energised site is gated by factory rates, by the scarcity of heavy-duty units and by permits and fuel supply.
It does not establish how much of those order books is for data centres, or for on-site plant. It does not establish the ~2 GW operating figure through any regulator or metering source. And Cleanview's own forward view is conditional: between 2.8 and 3.2 GW operating by end-2026, and a cumulative 13 GW by end-2027 only "if all projects with signed tenants reach their construction timelines—a big if", with a downside of about 5 GW1. Those are projections, and the range between them is the planning risk.
Treat on-site gas as capacity that exists when it is running, not when it is ordered. The defensible planning base for 2027 is Cleanview's downside of about 5 GW of on-site capacity in operation by end-2027 across the projects it tracks, not the ~90 GW announced and not the turbine order books, which belong to every customer the manufacturers serve.
For any specific campus your compute depends on, the decision test is four questions: is the generation equipment a firm order or a reservation; is it an aeroderivative or engine fleet that can commission in months, or a heavy-duty unit with 18 months of site work after delivery; is the air permit issued; and is the fuel supply contracted and physically connected. A project that cannot answer yes to all four is on the 60% of the list that is still an announcement, whatever its press release says.
Do not scale the national 52 GW, or Cleanview's 2 GW of gas, into a figure for data-centre storage.
Oversubscription shows demand for allocations; it does not show how much of the allocated time ran jobs.
Treat memory as a priced, volatile input with a public supplier side and a private buyer side, and plan on the private side.