On 6 July 2022, in Strasbourg, the European Parliament rejected the motion that would have blocked the Complementary Climate Delegated Act. Final tally: 328 in favour, 278 against, 33 abstentions. Fifty votes of margin out of 639. From that moment on, nuclear power, together with natural gas, entered the EU Taxonomy of sustainable investments.
For financial markets, and by extension for anyone building data centers in Europe, the implications are larger than the political coverage suggested.
What the EU Taxonomy actually is
Regulation 2020/852, in force since 2020, is not an environmental law. It is a law about capital.
It establishes a common dictionary of "sustainable" economic activities meant to direct private investment flows. Six objectives: climate mitigation, adaptation, water, circular economy, pollution, biodiversity. Three tests:
- Substantially contribute to at least one objective.
- Do no significant harm to the others (the DNSH principle).
- Meet minimum social and labour safeguards.
An activity that clears these tests can be labelled "taxonomy-aligned". For European banks, pension funds and asset managers, that label is not a vanity tag: it is the foundation of their disclosure obligations under the SFDR and, since 2024, under the CSRD.
In plainer terms: no Taxonomy alignment, no green bond.
The 2022 delegated act and the political compromise
The Complementary Climate Delegated Act (CCDA), adopted by the Commission in January 2022 and in force from 1 January 2023, added two contested entries: nuclear and natural gas, classified as transitional activities.
The DNSH conditions for nuclear are demanding, at least on paper:
- an operational plan for a deep geological repository for high-level waste by 2050 (no EU member state has one today);
- adoption of accident-tolerant fuel by 2025;
- a dedicated financial fund for decommissioning and waste management;
- construction permits for new reactors granted by 2045.
Austria and Luxembourg filed a case before the Court of Justice of the EU seeking annulment. The case is still pending. The regime is operational regardless, and the first nuclear-eligible green bonds were issued in 2023 by EDF.
The three Europes of nuclear power
The Union does not speak with one voice. A clear geography has emerged, and it shapes where it will be financially attractive to locate the next wave of data centers.
| Country | Nuclear in mix 2024 | Policy stance | Active hyperscalers |
|---|---|---|---|
| France | 70% | EPR2 programme, six new reactors | AWS Paris, OVH, Scaleway |
| Finland | 33% | Olkiluoto 3 in operation since 2023 | Google Hamina, Microsoft Espoo |
| Sweden | 30% | Post-2022 nuclear revival plan | AWS Stockholm, Microsoft Gävle |
| Czech Republic | 36% | Dukovany tender awarded 2024 | Microsoft Prague |
| Hungary | 47% | Paks II under construction | Limited |
| Germany | 0% | Atomausstieg completed 15 April 2023 | AWS Frankfurt, all majors |
| Spain | 20% | Phase-out scheduled 2027-2035 | Microsoft Madrid, AWS Aragón |
| Belgium | 41% | Phase-out postponed to 2035 | Google Saint-Ghislain |
| Italy | 0% | 2025 nuclear bill under debate | Few hyperscale DCs |
In 2023, in Paris, the European Nuclear Alliance was founded: fourteen member states coordinating common positions in Brussels. On the opposite side, the "Friends of Renewables" group led by Berlin, Madrid and Vienna. The two coalitions clash on every delegated act that follows the CCDA, including the low-carbon hydrogen package.
Why a data center operator should care
The most immediate effect runs through the cost of capital. A data center powered by a dedicated PPA with a French nuclear plant can today:
- be financed through green bonds issued under the EU Green Bond Standard in force since December 2024;
- access European Investment Bank credit lines reserved for taxonomy-aligned activities;
- compress the spread demanded by ESG investors, in some cases by 15-25 basis points according to Climate Bonds Initiative 2024 figures;
- enter the portfolios of Article 9 SFDR funds, until now closed to operators relying on natural gas even when efficient.
Then there is the reporting front. The CSRD requires large undertakings, hyperscalers included, to disclose detailed Scope 1, 2 and 3 emissions. Nuclear electricity carries an emission factor of 12-25 gCO2/kWh, against 400-900 for combined-cycle gas and 820-1,000 for residual German coal. For an operator selling compute capacity to European financial or public-sector customers, that gap flows directly into the client's own sustainability accounts.
The point is particularly sensitive for AI workloads. A new-generation GPU training cluster draws between 30 and 100 megawatts continuously for months. If that consumption is covered by certified low-carbon electricity, the resulting product (a foundation model, an inference service) carries a radically different emissions profile. Commission proposals on the AI carbon footprint, expected in 2026, are likely to move in this direction.
Finally, there is price stability. The French nuclear PPAs signed in 2023-2025 by Microsoft, Amazon and Meta sit around 70-80 €/MWh on 10-15 year horizons. Iberian solar is cheaper during daylight hours, but requires storage and backup for the 24/7 baseload of an AI data center. In the United States, Microsoft's September 2024 restart deal with Constellation for Three Mile Island Unit 1 is the explicit template several European operators are trying to replicate with EDF and Vattenfall.
The other side of the ledger
It would be naive to present the Taxonomy as an unqualified windfall.
First problem: the DNSH test is largely hypothetical. No EU member state currently operates a deep geological repository for high-level waste. Finland's Onkalo is the most advanced site, but commissioning is not expected before the end of the decade. Issuers of nuclear-eligible green bonds therefore lean on plans, not on commissioned facilities.
Second: the greenwashing accusation. Several NGOs and a meaningful share of institutional investors view the nuclear label as a political compromise rather than a technical verdict. Storebrand, PensionDanmark and other Nordic funds have excluded nuclear from their "dark green" portfolios even after 2022.
Third: the long-term lock-in. An EPR2 reactor has a 10-15 year build time and a 60-year operating life. A solar park is built in 18 months and pays back in eight years. For anyone planning data center capacity beyond 2040, the question is not only "is it green", but "is it the right technology for the load profile?".
What to expect over the next eighteen months
The CJEU ruling on the Austrian challenge is expected by the end of 2026. An annulment of the nuclear inclusion would force the Commission to rewrite the CCDA, with potentially retroactive effects on green bonds already issued. The scenario, according to Bruegel analysts, remains unlikely but not negligible.
On the industrial side, France aims to close contracts for the first three EPR2 reactors by 2027. The Czech Republic awarded Dukovany to KHNP in 2024, with commercial operation targeted for 2036. Poland signed with Westinghouse for the first AP1000 at Choczewo.
For Italian data centers the picture remains peculiar. Without domestic nuclear generation and with a power mix still heavily gas-dependent (above 45% in 2024), Taxonomy alignment runs through green electricity imports via interconnectors or large-scale solar PPAs. The nuclear bill currently in the Italian Senate would change the horizon, but on timelines that stretch well past 2035.
In the meantime, operators planning capacity in France or the Nordics start with a measurable financial advantage. It is not a victory of nuclear over renewables. It is, more prosaically, a victory of regulatory classification over the market. Which is precisely what the Taxonomy was designed to do.