45 Nodes on Ice

There is a spreadsheet on Red Eléctrica's website that, for anyone trying to build a data centre in Spain, has become a kind of horoscope. Updated on the 17th of March, it lists 45 nodes on the high-voltage transmission grid that have been quietly set aside. The power at those nodes exists. The wires are there. The capacity is real. And none of it can be handed to a developer, because it has been reserved for competitive auctions—"concursos de demanda"—that, as of this summer, have not been held even once.

That is the paradox at the centre of Spain's data-centre boom, and it was the one a recent ATA Insights webinar, "Effective permitting of data-centre projects in Spain," set out to untangle. The two panellists were well chosen to complement each other: Eloy Unda, a partner at PQC, an engineering and consultancy firm that does nothing but data centres, and Lidia Fernández, a senior associate in the regulatory practice at law firm Watson Farley & Williams. One knows where the cooling units go on the roof; the other knows why the grid connection may never arrive. Between them they sketched a picture of an industry with every advantage except the one that matters most.

What everyone wants, and what a data centre actually is

Unda opened with a useful reminder that the "cloud" is a building. "This isn't happening in the cloud, it isn't happening in some vague cyberspace," he said. "It's happening in a place, and it happens in a building called a data centre." Every WhatsApp message, every Bizum transfer, every Netflix stream and every query to a chatbot lands, eventually, in a hall full of racks that never, ever switches off. "A data centre can't stop, not on the 15th of August at three in the morning, not for ten minutes. Never. Never go to zero."

That "never" is what makes the buildings so peculiar to permit. They draw enormous, constant power—Unda noted that a single new-generation AI chip can pull hundreds of watts, and a hyperscale campus tens or hundreds of megawatts, not in spikes but as a flat, unrelenting baseline. They need height between floors (five metres is comfortable, against the two or three of an office block), heavy equipment on the roof, and diesel generators outside that make noise the neighbours can hear. Every one of those traits is a line item in a permitting file.

Unda was also keen to bury a couple of myths before they harden into political objections. Water, first. The reputation for guzzling it comes from an older evaporative-cooling fashion that traded water for energy; the industry, he said, is "backing away" from it toward closed systems that need "thousands of litres" to fill once, on day one, "and after that, practically nothing." Only that morning, he noted, one hyperscaler had announced its Spanish sites would use no water at all—not, he was careful to add, by inventing anything, "simply using technology that already exists, improved." Then the "shoebox" jibe—the idea that a data centre is a box that consumes power and creates no jobs. Look at Zaragoza, he countered, where an American hyperscaler's arrival a few years ago turned the area into a technology pole. "Nobody asks how many jobs a motorway creates," he said. "It's necessary infrastructure."

Reading the land before you read the law

Before regulation ever enters the picture, a site has to survive a checklist, and Unda's was long. Plot size scales with ambition: low-density cloud workloads need roughly 1,000 buildable square metres per megawatt of IT load, while dense AI clusters can be squeezed into 600–700. Zoning is where timelines live or die—a plot on a mature industrial estate with services already run is a different animal from rustic land that must be reclassified. Acoustic rules should be industrial, with no homes nearby, because "if the police come and make you stop the cooling over a noise complaint, it's an outright catastrophe." Then flood risk (the standard test is that the land has not flooded in a hundred years), aviation easements that cap building height, contaminated former-industrial soil, and unpleasant neighbours a future tenant will refuse to sit beside.

And behind all of it, the supply that no clever site selection can conjure. "Electrical power is what everyone is chasing," Unda said. Fibre, in Spain, is comparatively easy; water need not be enormous; latency dictates only whether the building must sit near a city or can chill quietly in Iceland. Power is the constraint. Which is where Fernández took over.

The law that changed the game

For years, Fernández explained, demand-side grid access was barely regulated—so barely that, in her firm's telling, permits became a commodity. "There was a feeling that these weren't real projects, but rather a bit of permit-trading," she said. The legislator agreed. In December 2023, Royal Decree-Law 8/2023 rewrote the rules for demand access and connection, deliberately modelling them on the regime already governing renewable generation. The preamble, she noted, says so out loud: a sharp rise in demand permits, data centres among them, and "speculative behaviour" that needed reining in. "It recalls very much what happened with renewable generation in 2018 and 2020."

The single biggest change is money up front. Requesting a demand connection at 36 kV or above now requires a financial guarantee of €40 per kilowatt. Fernández was blunt about a persistent misunderstanding: "People ask me a lot, but isn't it €20? It's not €20, it's €40. The €20 is only for batteries." Nor is depositing the guarantee the finish line. It must be validated by the competent authority—usually the regional deposit office—a process that takes roughly three months, and only with that validation in hand can the developer actually lodge the access request. "It's not automatic," she said, twice, because that too is a question she fields weekly.

Two more changes bite. Permits now expire after five years, within which the developer must sign an access contract with the local distributor and commit to drawing at least half the access power in the peak tariff period—a commitment locked in for a further three years. And once a plot is designated, its geometric centre cannot be moved more than ten kilometres. For most data centres that is survivable, but as Unda's site-selection horrors showed, plots do fall through.

The 45 nodes, and the paradox of the pre-contract

Then the reserved nodes. When demand at a transmission node outstrips its capacity, the rules allow it to be ring-fenced for a future auction rather than allocated first-come-first-served. As of Red Eléctrica's mid-March update, Fernández said, 45 transmission nodes sit reserved for demand concursos—"which is a lot." The capacity is there. It cannot be granted until the auctions run. And "so far not a single one has been held."

Worse, the sequencing borders on the absurd. Under the CNMC's Circular 1/2024—in force since January 2025, though many of its most useful articles are not—a developer must submit, alongside the access request, a property contract, lease or a pre-agreement over the specific plot. "You still don't know whether you'll have power," Fernández said, "but they're asking you to have a contract for the land." A developer must therefore sink real money and real time into securing a site before knowing whether a single megawatt will ever be available to it. "This creates an insecurity that makes many developers hesitate," she said—hesitate over whether to advance at all, and how much to spend chasing a connection that may not exist.

The transparency that would ease all this is written into the same Circular but not yet switched on. Grid operators must eventually publish, node by node, what capacity is available, occupied and in the pipeline—a long-awaited measure. It will not take effect, Fernández noted drily, until the "specifications of detail" say so, and those have no start date at all. Some obligations, she added, have no entry-into-force date "not even foreseen," which "isn't very intuitive and generates confusion. But it's what we have."

From "impossible" to merely difficult

For all the frustration, Fernández's account was, at heart, an opportunity arc. Regions are learning to compete. Aragón—home to that Zaragoza hyperscaler—has passed rules letting a qualifying project be declared strategic, unlocking faster processing and, she said, real relief on timelines. The Circular's coming rules on how demand capacity is calculated could "surface additional capacity." A new transmission-grid plan is in its early stages, with the minister signalling only last week that industrial consumption will be a central axis of it. And the caps on grid investment—criticised, Fernández said, by "everyone, or almost everyone"—look likely to be lifted, because part of the capacity shortage is simply that there is not enough wire.

There are workarounds for the impatient, too. Unda's first is unglamorous but reliable: phase the build. Nobody develops 200 megawatts overnight, so take the connection you can get, energise the first tranche, and chase the rest. On-site generation—gas turbines, the fashionable answer—he treated with an engineer's scepticism: technically fine, but "with what it costs you to build and operate it," the business case is shaky, and a self-generating campus may simply be uncompetitive against one plugged into the grid. There is also the much-asked exception under article 6.9 of the access decree, letting demand attach to a generation node in a self-consumption arrangement—capped at half the connected generation's capacity, and hemmed in by the fine print of Spain's self-consumption rules.

Kicker

Spain's pitch to the world's hyperscalers is genuine: cheap clean power, cool northern sites, the fibre highways running Lisbon–Madrid–Barcelona and up to Bilbao. What the webinar made plain is that the bottleneck is no longer geography or engineering—it is a queue, and a queue that has not yet started moving. Forty-five nodes sit on ice, waiting for an auction with no date. The developers who win will be the ones who understood the paperwork before their rivals did: who deposited the right guarantee, read the right Circular, and picked a region that wanted them. As Fernández put it, the sector should learn the lesson the renewables industry learned the hard way—explain yourself early, "and don't leave the discourse only to those who oppose you." The land is ready. Now someone has to turn the wires back on.

The full session is available to watch on demand from the ATA Insights webinar archive. The conversation continues in person at RENMAD Datacenters in Zaragoza, where Lidia Fernández (Watson Farley & Williams) joins the line-up alongside PQC — the place to hear whether those 45 nodes have finally come off ice.