Summary

  • Mistral Compute's public numbers describe at least four different things: a 1,400 MW design ceiling for the Campus AI campus at Fouju that remains in permitting; 700 MW of grid capacity pre-reserved with transmission operator RTE and explicitly not an accepted connection; staged connection tranches of 240 MW by the end of 2027 and 700 MW before the end of 2029; and 44 MW of powered capacity with 13,800 Nvidia GB300 accelerators at the Eclairion-owned Bruyères-le-Châtel site, financed by $830m of first-ever debt.
  • No document surfaced in this review records a dated energisation event for the 44 MW, yet a facility tracker labels the site "Operational" while the same record carries "Operational: not published" and names an end-June 2026 target; a separate aggregator asserts the site runs 18,000 GB200 systems, a fleet that cannot be the 13,800 GB300 units the debt financed.

The layer with a signed loan behind it

The most transaction-backed figure in the record is 44 MW. Reuters reported on 30 March 2026 that Mistral raised $830m in new debt — the company's first debt raising — to buy 13,800 Nvidia chips for a major data centre near Paris. Data Center Dynamics tied the same financing to 13,800 Nvidia GB300 GPUs and 44 MW of powered capacity at a site in Bruyères-le-Châtel, south of Paris, owned and run by French data centre firm Eclairion, with Mistral intending to start operations there by the end of June. CNBC named the seven lenders — Bpifrance, BNP Paribas, Crédit Agricole CIB, HSBC, La Banque Postale, MUFG and Natixis CIB — and reported the same 13,800 GPUs and 44 MW with operations targeted in the second quarter of 2026, alongside a stated objective of 200 MW across Europe by the end of 2027.

Committed money against named hardware and a stated power envelope is a stronger class of evidence than a status label. It is still evidence about financing and delivery, not about serviceability. The same report recorded what the financing replaced: an earlier plan to procure 18,000 Nvidia GB200 GPUs from French cloud provider Scaleway at a 40 MW site opening in summer 2025, which was delayed, with Mistral opting for the newer hardware generation instead.

The 2025 announcements describe a different cluster

Fluidstack's March 2025 announcement said the cluster for Mistral AI would be housed at Eclairion's 40 MW site in Bruyères-le-Châtel, roughly 40 km south of Paris, designed to scale beyond 18,000 GPUs with potential expansion to 100 MW+, with the first tranche slated to be operational by summer 2025 and powered by 100% decarbonised electricity. Nvidia's June 2025 announcement described Mistral AI building an end-to-end cloud platform on 18,000 Nvidia Grace Blackwell systems in the first phase, with expansion across multiple sites planned in 2026.

Set against the March 2026 financing, three quantities move at once: 18,000 systems becomes 13,800; 40 MW becomes 44 MW; summer 2025 becomes an end-June 2026 operating intention. Those are not rounding differences. They describe different fleets and different dates, and only the later set has a disclosed financing behind it.

Mistral's own timeline stops short of a megawatt

Mistral's compute page gives a company timeline: July 2025, GB200 racks land; December 2025, GB300 arrives and the alpha stack is live on GB200; February 2026, GB200 serving production; a Sweden site with EcoDataCenter "in motion"; and a target of 1 GW of sovereign capacity at frontier scale across the EU by 2030. The page attaches no megawatt figure to any of those dates, and terms such as "racks land" and "serving production" are not defined there, so the timeline is a sequence of events rather than a capacity measurement.

At the AI Now Summit on 28 May 2026, CTO Timothée Lacroix described the existing 40 MW facility at Bruyères-le-Châtel, built in collaboration with Eclairion, as having been training models since early 2026, and set out a 10 MW inference-only site at Les Ulis in Essonne opening in the third quarter of 2026 plus a Borlänge, Sweden site planned through 2027 to host Nvidia's Vera Rubin GPUs, within what VentureBeat reported as a €4 billion programme in France and Sweden targeting 200 MW by 2027 and 1 GW by 2030. That account pairs 40 MW with training "since early 2026"; the March financing pairs 44 MW with an intention to start operations by end-June 2026. Whether those describe the same capacity layer, a planned increase, or two different measurement conventions is not established by either document.

The grid: pre-reservation, then tranches, then a ceiling

The Fouju campus adds a second kind of number. RTE, the French transmission operator, states that the State asked it to pre-reserve capacity on four sites, including 700 MW at the ZAC des Bordes site in Fouju, Seine-et-Marne, under a procedure approved by CRE on 7 May 2025 for rapid connection of very high-power consumption facilities. Its own wording is decisive: pre-reserved capacity "is immediately reserved and will be taken into account in the exploratory studies and technical and financial proposals (and not accepted)". Pre-reservation is a queuing instrument, not a connection.

The project's public consultation page describes the connection in two phases — a first 700 MW under the Fast Track programme for the initial phases, then 1,400 MW to supply the campus at full capacity — and states that, as of its text, contracting between RTE and Campus IA covers only that first 700 MW. It requires a new 400 kV substation cut into the 400 kV Chesnoy–Morbras 1 and 2 lines, and targets progressive commissioning from 2028.

A Campus IA and RTE accelerated-connection announcement puts finer numbers on the same sequence: a first power tranche of 240 MW available by the end of 2027, a second tranche of 700 MW before the end of 2029, with electrical infrastructure designed to allow a rise to 1,400 MW — framed as a design capability, not as contracted power. The BEP Research tracker attributes to a May 2026 French Senate question record confirmation of the 1.4 GW target and the public inquiry, and states that only 700 MW has so far been contracted with RTE, half the headline figure; the same tracker lists the project as being in permitting with an expected December 2028 date.

Read together, 1,400 MW is an engineering envelope, 700 MW is the first contractual phase, and 240 MW is the nearest dated tranche. Quoting any one of them as "capacity" without its category overstates what is committed.

The label problem

Two third-party records apply an operating status that the primary financing reporting does not. Scrutica's facility record lists the site as "Operational" with 44 MW recorded as operating capacity and 13,800 GB300 Grace-Blackwell GPUs, Eclairion as owner and operator, and an announcement date of 30 March 2026 — while the same record carries "Operational: not published" and describes the operational date only as a target of end-June 2026. On 18 June 2026, AI Chat Daily asserted that "Mistral's 44MW Bruyères-le-Châtel site is operational with 18,000 NVIDIA GB200 systems", framing it as the first node of a 200 MW European roadmap by 2027 and a planned 1.4 GW Campus AI hub. That fleet count cannot describe the same fleet as the 13,800 GB300 units the debt financed.

A record that simultaneously asserts a status and notes the absence of the underlying event is evidence about labelling practice, not about capacity. The practical consequence for a reader is narrow but important: as of the documents reviewed here, there is no published energisation event, no metered-load figure, and no acceptance notice that would convert 44 MW from a financed envelope into serviceable capacity on a stated date.

What would settle the question

Four documents would resolve most of the ambiguity, and none appears in the record reviewed here: a dated energisation certificate or metered-load publication for the Bruyères-le-Châtel site; the executed RTE connection contract with its tranche schedule and milestone terms; the $830m facility agreement with its drawdown conditions and security over the accelerators; and asset-level delivery records for the 13,800 units.

Until at least one of those exists publicly, the defensible statement is that Mistral Compute has financed and is installing a 44 MW cluster in Essonne against an operating intention, while the larger campus figures remain designed, pre-reserved or staged capacity rather than connected capacity.