Data centres: Spain ties grid access to 80% renewable power, hour by hour

A grid permit with new conditions attached

On 27 August 2026 Spain's ministries for the Ecological Transition, the Economy and Digital Transformation put to public consultation a draft royal decree on the energy-sustainability, resilience and digital-sovereignty requirements for data centres, under an urgent procedure authorised by the Council of Ministers on 25 August, with comments due by 4 September FACT. The mandate dates from March: the first additional provision of Royal Decree-Law 7/2026 (BOE, 21 March) ordered those requirements to be set by royal decree, including "additionality and hourly-correlation criteria" for renewable consumption, and provided that non-compliance could cost a data centre its grid access and connection permits FACT.

The legal basis existed; what is new is the quantification INTERPRETATION. Data centres of 1 MW or more — aggregating sites under the same owner — will obtain or keep their permits only if they cover 80% of their consumption through self-consumption or renewable power purchase agreements with plants located in Spain whose commissioning certificate is no more than 18 months older than the data centre's start of operation (Article 8), and if in every hour at least 80% of the energy consumed is backed by renewable generation from that same hour (Article 9) FACT. Qualifying contracts must name specific plants, run for at least ten years, be executed as a public deed and exclude both financial hedges at parent or group level and organised-market products backed only by guarantees of origin (Article 12) FACT.

In the ministry's words, "every new megawatt consumed must be accompanied by a new renewable megawatt installed in the previous 18 months" FACT.

What the headline leaves out

First, the calendar. The consultation did not close on 4 September. By a resolution of the Directorate-General for Energy Planning and Coordination dated 2 September, at the request of "several interested parties", the deadline was extended to 10 September 2026 at 17:00, with no change to the text FACT. That deadline did indeed close on 10 September at that hour, amid a final wave of comments and criticism from industry associations (SpainDC, APPA, AEE) and several regional governments — Comunidad de Madrid, Aragón, Andalucía, Extremadura and Cantabria — with no government concession on the 80% hourly requirement reported by the press consulted as of the close FACT. After that, according to the regulatory impact assessment, the draft goes to the competition and markets authority (CNMC), the Office for Regulatory Coordination and Quality and the Council of State for their reports, all on an urgent track, and enters into force twenty days after publication in the Official Gazette (BOE) FACT.

Second, the 80% hourly rule is not the only route. Article 7 deems the requirements met when the system's renewable share exceeds 90% in year n-2, subject to an annual cap on hours of grid consumption FACT. And the third additional provision empowers two directorates-general to amend by resolution that 90% share, the 80% figures, the 18-month window and the hourly resolution, as a "technical or methodological update" FACT.

Third, the surcharge scale is wider than the "65–500%" of most summaries. Article 10 sets, on network access tariffs and system charges: 65% on every invoice of a year in which the hours cap is exceeded (+10 points per consecutive year); for additionality shortfalls, 500% if additional renewable supply covers less than 20% of annual consumption, 400% at 20–40%, 300% at 40–60% and 100% at 60–80%; and for hourly-matching failures, 10% if fewer than 5% of the month's hours fail, 30% at 5–20% and 50% from 20% (+10 points per consecutive month) FACT. The full range is therefore 10% to 500%, compounding over time FACT.

Data point. According to the regulatory impact assessment, the surcharges are not revenue for the state budget: they are settled within the electricity system's liquidations and reduce what other consumers pay. The assessment does not quantify expected proceeds or the compliance cost per project FACT.

Fourth, losing the permit. Article 11 treats as significant and repeated non-compliance — grounds for extinction, after a hearing and by a challengeable decision — additionality below 60% or 20% or more of hours in breach for five consecutive years FACT.

Six months for permits already granted

The associations call this a legal-certainty problem. Access applications still pending when the decree takes effect fall under the new rules and will be refused unless the requirements are evidenced within three months (first and second transitional provisions). Projects holding a permit but not yet connected have six months; after that, permits lapse and guarantees are enforced (third transitional provision), unless the holder withdraws within the same period, in which case the guarantees under Royal Decree 1183/2020 and Royal Decree-Law 8/2023 are not enforced (second additional provision). Until the EU label arrives (expected August 2027), a PUE of no more than 1.15 also applies FACT.

The government itself gives the scale. According to MITECO, more than 12 GW of access and connection rights have been granted to data centres since 2021 — more than 6 GW on the transmission grid since Royal Decree-Law 8/2023 and about 6 GW on distribution networks since 2020 — while the 2024 Artificial Intelligence Strategy projects 2.5 GW of computing capacity in 2030, equivalent to 3.5–4 GW of electricity demand FACT. No open series from Red Eléctrica or the CNMC breaks those 12 GW down by node or maturity; the share of speculative reservations is a claim by the government and the industry, not a verified figure FACT.

The precedent the government cites is looser

The press release presents additionality and hourly matching as criteria already in use, "as is the case with renewable hydrogen" FACT. Commission Delegated Regulation (EU) 2023/1184 treats temporal correlation as met on a monthly basis until 31 December 2029 and requires hourly matching only from 1 January 2030 (Article 6); treats a renewable installation as new if commissioned no earlier than 36 months before the electrolyser (recital 9); and exempts installations operating before 1 January 2028 from additionality until 1 January 2038 (Article 11) FACT.

The Spanish draft for data centres requires hourly matching from day one, plants no older than 18 months and no additionality transition at all: stricter on all three parameters than the EU's own hydrogen rules FACT. Whether Spain is "pioneering" or whether this is "the most restrictive framework in the EU" are statements by MITECO and SpainDC respectively; they have not been tested here against the other 26 member-state regimes INTERPRETATION.

What the associations are asking for, with their numbers flagged

SpainDC, the data-centre association, announced on 31 August that it would file comments and asked for a longer deadline and a technical working group; it cites €66.9bn of cumulative investment over 2026–2030 in a continuity scenario (36% less in a restrictive one) and estimates that, as drafted, the text would put 80–90% of the new investment that could choose Spain at risk ESTIMATE. These are the association's own estimates, without audited methodology; the extension came on 2 September, although the resolution does not say who asked for it FACT.

On 7 September the renewables industry joined in. APPA Renovables asked to replace the 80% hourly rule with 100% renewable supply on an annual basis in a first phase; its simulation, using 2025 hourly profiles and four-hour batteries, estimates that compliance would require 3.93 MW of solar, 3.69 MW of wind and 3.65 MW of batteries per MW of data centre — 11.26 MW in total — and states that more than a quarter of renewable output is already curtailed ESTIMATE. The wind association AEE asked the same day for four time blocks instead of hourly matching and for the additionality window to be widened from 18 to 36 months, the threshold in the EU hydrogen regulation FACT. The 11.26 MW-per-MW figure is an interested party's estimate; what is verifiable is that three associations with different interests converge on annual or block-based accounting and more additionality headroom INTERPRETATION.

The case for the decree: rationalising, not pricing out

The strongest counterargument deserves space: the draft does not make access dearer, it rationalises it. More than 12 GW have been granted against 3.5–4 GW of demand in 2030, and the rule gives project-less reservations an exit without enforcement of guarantees that they lack today. Flat, non-dispatchable demand raises the system's need for firmness; in a marginal-pricing market that firmness comes from gas and is paid by everyone, so the 80% hourly rule internalises a real cost and the surcharges, settled inside the system, flow back into the tariff. APPA itself acknowledges more than 25% of renewable output is curtailed: generation is in surplus and what is missing is demand and storage at the right nodes, which is what additionality with batteries forces to be built; and the third additional provision allows the parameters to be relaxed without reopening the decree OPINION.

That argument qualifies the thesis on one point: the design is defensible as a price signal for firmness, in the line of the Almaraz extension to 2030, when Spain began putting a price on security of supply. It does not weaken it on the other: the regime remains stricter than the EU hydrogen rules on all three verified parameters and applies to permits already granted with a six-month deadline. That, not the renewable target, is what the three associations are contesting INTERPRETATION.

Firmness two ways, and one still open

Texas solved the same problem with a different instrument. Senate Bill 6, in force since 20 June 2025, requires the state regulator to set a 75 MW threshold for large loads, obliges those customers to disclose information and pay a study fee of at least US$100,000 for the initial transmission assessment, and allows ERCOT, during an energy emergency alert and after exhausting market services, to direct the load to deploy its backup generation or reduce consumption, counted as firm load shed FACT. Same firmness problem, different tool: Texas conditions access on curtailability; Spain on additionality and hourly matching INTERPRETATION.

Within Spain, Aragón, which generated 22,365 GWh in 2025 (83.4% renewable) and exported 51.5% of it, names transmission-grid capacity as the main brake on new investment, with the 2026–2030 grid plan still unpublished FACT: the bottleneck is the grid, decree or no decree INTERPRETATION. The Mexican end remains open: this analysis could not verify from primary sources either the data-centre demand projected in PRODESEN or the interconnection capacity available in Querétaro, so any comparison with Mexico should be read as pending, not as a conclusion FACT.

What changes for capital

For anyone financing or developing a data centre in Spain, the variable being repriced is not the electricity price but the mandatory supply structure and the administrative risk: a bankable ten-year PPA with a new, named plant, no group-level hedges, and a permit whose expiry triggers enforcement of guarantees INTERPRETATION. The operative question is the calendar: comments until 10 September, CNMC and Council of State with no public date, BOE plus twenty days, then three months for pending applications and six for unconnected permits. No figure is final until the BOE; this analysis does not predict the final text or the Council of Ministers' decision.

For capital moving between Spain and Mexico, the lesson is one of method: the comparable cost across jurisdictions is not the kWh but firmness — who provides it, for how long and on what security — and that is what to read in the articles before they reach the Gazette.