Nuclear PPAs for data centres: the 2026 European guide (SMR, baseload, pricing)

TL;DR — the essentials in 60 seconds

A nuclear PPA (Power Purchase Agreement) is a long-term electricity offtake contract (10 to 20 years) backed by a nuclear plant, delivering 24/7 baseload supply — unlike solar or wind PPAs, which are intermittent by nature. Three models coexist in Europe in 2026: PPAs with an existing plant (France's new post-ARENH framework is a direct example), SMR projects led notably by Rolls-Royce and EDF/Nuward, and direct data centre–reactor coupling, popularised in the US by Microsoft–Constellation (Three Mile Island) and Amazon–Talen Energy (Susquehanna). Prices vary widely by market: around €65-70/MWh for French long-term industrial contracts post-ARENH, versus $100-115/MWh for the flagship US deals. Nuclear availability (capacity factor) generally exceeds 85-90%, against 15-45% for wind and solar. For AI data centre operators, the question is no longer "nuclear or renewable" but a 24/7 carbon-free mix — exactly what Voltarione lets you build on a single map.

What is a nuclear PPA?

A nuclear PPA is a bilateral contract in which a buyer — data centre, hyperscaler, electro-intensive industrial — commits to purchasing a defined volume of electricity generated by a nuclear plant, at a price fixed or framed in advance, over a long duration.

The fundamental difference with a renewable PPA lies in the generation profile:

• A solar or wind PPA delivers intermittent energy, with an average capacity factor of 15 to 45% depending on technology and geography.
• A nuclear PPA delivers baseload energy: stable, continuous output, with a capacity factor generally above 85-90% outside scheduled maintenance outages.

For an AI data centre, whose compute load is continuous and critical, that stability has direct operational value: less dependence on battery storage, less reliance on backup supply, and a carbon footprint smoothed across 24 hours rather than correlated with sun or wind.

The 3 nuclear PPA models in Europe in 2026

1. PPA with an existing plant

The most mature model — and the one that has just been deeply reshaped in France. ARENH (regulated access to incumbent nuclear power), which capped alternative suppliers' access to 100 TWh/year of EDF nuclear output at €42/MWh, expired on 31 December 2025. Since 1 January 2026, two new schemes replace it:

• The Universal Nuclear Payment (VNU), a redistribution mechanism triggered when EDF's revenues exceed certain price thresholds (€78/MWh and €110/MWh), returning 50 to 90% of the excess to consumers.
• Nuclear Production Allocation Contracts (CAPN), reserved for electro-intensive industrials: bilateral 10-to-15-year contracts negotiated directly with EDF, generally priced between €65 and €70/MWh — EDF expects 1,800 MW of capacity available through this channel, deliverable from 1 January 2027.

This new framework — built on logic close to a Contract for Difference between the French state and EDF — is the most direct entry point for a European data centre seeking existing nuclear capacity at a negotiated price.

2. SMRs (Small Modular Reactors) under development

Small modular reactors (typically 300 to 500 MW) are designed for faster, more standardised deployment than conventional reactors. 2026 marks a clear acceleration in Europe:

• Rolls-Royce SMR stands out as the continent's most advanced developer, with three major contracts already signed: in the UK (technology selected by Great British Energy – Nuclear for the Gwyndod site in Wales), in the Czech Republic (early works contract with ČEZ for up to 3 GW at the Temelín site), and in Sweden (selected in June 2026 by Videberg Kraft — a Vattenfall subsidiary — for three 470 MW reactors on the Värö peninsula, Sweden's first nuclear project in over 40 years, backed by a public support mechanism of roughly €19.7 billion over 12 years).
• Nuward (an EDF subsidiary) revised its design in 2024 after several delays, refocusing on proven technologies: a 400 MWe reactor with a cogeneration option. Conceptual design is targeted for mid-2026, with detailed design now announced for 2031. A Joint Early Review already brings together eight European nuclear safety authorities — France, the Netherlands, Poland, Sweden, Finland, Czechia, Belgium and Italy — with its third phase started in January 2026.
• In Poland, the government approved a Rolls-Royce SMR project, and industrial group Industria is exploring the technology to decarbonise a hydrogen cluster.

Upside: capacity designed from the outset for dedicated coupling with an industrial site or data centre, with unprecedented cross-border standardisation momentum. Constraint: a realistic commissioning horizon between 2030 and the mid-2030s for the first projects; contracts signed today cover future capacity.

3. Direct data centre–reactor coupling

The model popularised in the United States, with two references that now frame the entire European discussion:

• Microsoft–Constellation: a 20-year PPA signed in 2024 to fund the restart of Three Mile Island Unit 1 (835 MW), renamed Crane Clean Energy Center, for an investment of roughly $1.6 billion and a targeted return to service in 2028. Analysts estimate the price between around $102/MWh (BMO Capital) and $110-115/MWh (Jefferies) — a significant premium over market prices, justified by volume and long-term guarantees.
• Amazon–Talen Energy: after a 2024 acquisition of the Cumulus data centre campus (960 MW) adjacent to the Susquehanna plant for roughly $650 million, the two groups signed an expanded PPA in June 2025 covering up to 1,920 MW of "front-of-the-meter" capacity, ramping in 120 MW increments through 2042, with joint exploration of new SMRs on Talen's Pennsylvania land.

In Europe, direct coupling remains embryonic, but growing interest in SMRs dedicated to industrial sites — notably in Sweden, Czechia and Poland — points to a comparable trajectory in the medium term.

Price and availability

The two markets (regulated French/European vs US over-the-counter) are not directly comparable: they reflect very different regulatory frameworks and premium levels.

Nuclear vs intermittent renewables

Key European countries for nuclear PPAs

• France — Europe's largest nuclear fleet, new CAPN/VNU framework live since January 2026, Nuward in detailed design. See the French market.
• Sweden — nuclear returns after 40 years, three Rolls-Royce SMRs selected (Videberg Kraft/Vattenfall), public support framework of nearly €20 billion.
• Czech Republic — ČEZ–Rolls-Royce SMR early works contract at the Temelín site, up to 3 GW targeted.
• United Kingdom — Rolls-Royce SMR selected by Great British Energy – Nuclear, first site at Gwyndod (Wales).
• Poland — government plan approved for a Rolls-Royce SMR, industrial interest in decarbonised hydrogen coupling.
• Netherlands, Belgium, Italy, Finland — joined the Nuward joint safety review, a sign that the SMR market is structuring at European rather than national scale.

Hybridising nuclear + renewables: the 24/7 CFE strategy

What most large buyers (hyperscalers, AI data centres) target is not "nuclear or renewable" but 24/7 carbon-free energy (CFE): pairing a stable nuclear base with renewables to optimise weighted average cost and supply resilience. Amazon-Talen illustrates it well: the nuclear PPA secures the base, while Amazon explores SMRs in parallel for future growth — a portfolio logic rather than a bet on one technology.

That is the logic Voltarione applies to its marketplace: rather than limiting the capacity search to a single technology, the platform lets you cross-reference nuclear, wind, solar, hydro and biomass sites on one map, with shared availability and price filters — building a mix that answers both the baseload need and the carbon constraint. A single entry point, where until now you had to approach utilities, SMR developers and brokers separately.

FAQ

Does a nuclear PPA guarantee a fixed price for the full term?

Terms vary by model: French CAPNs negotiate a long-term bilateral price with EDF, while US PPAs such as Microsoft-Constellation are fixed-price contracts over 20 years. France's VNU provides for redistribution if market prices exceed certain thresholds.

Can you sign a PPA on an SMR that isn't built yet?

Yes — that is the common structure of current European SMR projects: Rolls-Royce, ČEZ, Vattenfall and EDF have all signed agreements covering future capacity, with milestones tied to design, certification and then construction.

What is the difference between a nuclear PPA and the old ARENH mechanism?

ARENH was a French regulated scheme giving access to incumbent nuclear output at a fixed €42/MWh, which ended on 31 December 2025. It is replaced by CAPN (negotiated bilateral contracts) and VNU (a redistribution mechanism), at higher price levels (€65-70/MWh).

Is direct data centre–reactor coupling possible in Europe today?

The model is less widespread than in the US, but SMR momentum in Sweden, Czechia and Poland — with projects designed from the outset for dedicated industrial sites — is structurally close to it.

What is a realistic timeline to secure a nuclear PPA in Europe in 2026?

For an existing French plant, the first CAPN volumes are deliverable from January 2027. For an SMR, commissioning remains set between 2030 and the mid-2030s depending on the project.

Are European and US nuclear prices comparable?

Not directly: French CAPNs sit within a regulated framework (€65-70/MWh), whereas US deals such as Microsoft-Constellation reflect an over-the-counter market with a premium for restarting a dedicated asset ($100-115/MWh).

Going further

To explore nuclear and renewable capacity available across Europe, compare prices by technology and connect directly with producers, browse the Voltarione interactive map. See also: 24/7 hourly matching, corporate PPA, case studies, French market, by industry.

Sources

• World Nuclear News — EDF simplifies Nuward SMR design
• ASNR — Third phase of the Nuward joint review
• Rolls-Royce SMR — Our Progress
• Utility Dive — Constellation plans 2028 restart of Three Mile Island
• Utility Dive — Talen to sell Amazon 1.9 GW from Susquehanna
• Opera Énergie — ARENH 2026: upcoming mechanisms
• 8Advisory — France's post-ARENH market transformation