The draft Royal Decree being prepared by the Spanish government to regulate data centers would require facilities with an access capacity of 1 MW or more to back up at least 80% of their hourly energy consumption with renewable generation . This electricity must also meet an additionality criterion: consumption must be linked, through self-consumption or fixed-term contracts, to renewable capacity commissioned within the previous 18 months. Compliance will be tied to access and connection, with surcharges and the potential loss of permits.
For a facility that operates for virtually 8,760 hours, the requirements involve much more than simply contracting an equivalent annual volume of green energy. Solar and wind power do not produce continuously, so maintaining a high hourly correlation necessitates combining technologies, storage, and greater generation capacity.
“Why would we require a data center to provide 8,760 hours of power when we don't demand the same from any other industry that electrifies its facilities?” asked Jon Macías, president of the Association of Renewable Energy Companies (APPA), Self-Consumption section , in an interview with Energía Estratégica . Mandating a system capable of covering the entire annual demand would, in his opinion, be inefficient and could even incentivize the use of fossil fuels as backup.
“It makes no sense that our renewable and competitive electricity is used as an incentive for new investments and then, when these come, we tell them to develop their own generation units,” Macías stated.
A simulation previously released by APPA illustrates the gap between the regulatory percentage and the infrastructure required to achieve it. Using 2025 hourly energy profiles, four-hour battery backups, and 90% efficiency, each MW of demand would require 3.93 MW of solar, 3.69 MW of wind, and 3.65 MW of storage, equivalent to 14.6 MWh . Under these assumptions, the total exceeds 11 MW of assets for every MW of data center consumption.
Macías avoids applying that configuration to all projects. “There is no universally optimal combination,” he noted; the result will depend on the consumption profile, location, available space, connection capacity, PPA prices, and the cost and sizing of storage. Self-consumption, batteries, and long-term contracts will fulfill different functions depending on each installation.
The alternative is not to reduce renewable energy coverage. APPA proposes that, in the first stage, 100% of annual consumption be backed by renewable generation , with its corresponding traceability, and that the temporal correlation and additionality be tightened as storage, flexibility, and demand management advance.
“Additionality and greater temporal correlation are positive objectives, but we must avoid initially turning them into barriers that impede project development,” Macías explained. The association proposed favoring PPAs associated with new generation, upgrades, or storage, and progressively raising the requirements.
The data center would continue to respond to system conditions. “It must respond to market price signals and assume the corresponding tolls and charges,” Macías stated. As storage and demand management mature, these signals could incentivize consumption during peak electricity availability hours.
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12 GW granted: filter maturity without prioritizing sectors
The flexibility that APPA is demanding coexists with another problem: Spain already has around 12 GW of access granted to data centers , some 6 GW in transport and another 6 GW in distribution, compared to much lower forecasts for effective deployment by 2030. The association acknowledges that milestones, deadlines and guarantees are needed to prevent projects with no real expectation of execution from keeping capacity locked up.
“The requirements must be proportionate, allowing us to differentiate mature projects from those that are merely speculative, but without establishing such high guarantees that their own financial cost ends up hindering real projects,” Macías stated. APPA is asking for this logic to be applied to all large consumers, not just data centers.
The association also does not advocate for a pre-existing sectoral hierarchy when a data center, an industry that electrifies processes, and new residential consumption all compete within the same network hub. “If the projects are viable, we must try to integrate all the demand that the system allows,” Macías explained. Where capacity is scarce, he proposes objective, transparent, and non-discriminatory criteria linked to access and the maturity of the projects.
APPA links this position to another imbalance: according to Macías, Spain does not have a structural problem of insufficient generation, while in certain periods and under certain criteria , it may go unused by around a quarter of its potential renewable energy production . Strengthening the grid and incorporating new demand would allow for the absorption of a greater portion of that generation.
Batteries and load management to reduce pressure on the grid
The demand for a data center cannot be treated as completely flexible. Continuity of supply limits how much consumption can be shifted, but batteries can reduce peak demand, self-consumption can decrease energy drawn from the grid at certain times, and load management can move processes that can be shifted to times with greater renewable energy availability.
“It’s not necessarily about forcing all data centers to be flexible, but about establishing signals that make it economically attractive for those who can adapt part of their consumption to do so,” Macías stated. This scheme would allow storage to be used not only to meet renewable energy needs, but also to reduce peak loads and adapt part of the demand to system conditions.
The same logic applies to networks. The actions specifically required to connect a new supply should fall to the applicant when so determined by regulations, while structural reinforcements that benefit all consumers should remain within the general planning framework. APPA does not propose a different regime simply because the applicant is a data center.
The Government will have to decide what to keep from the draft
APPA's objections echoed the criticisms raised by SpainDC , which had already warned about the impact that accumulating requirements could have on projects under development and new investment decisions. The public consultation period for the Draft Royal Decree closed on September 10 , following an extension of the initially planned deadline.
The next version of the text will have to define whether the Executive maintains the 80% renewable energy requirement with hourly correlation and the additionality criteria , or modifies those conditions after the consultation. This will determine how much each data center must handle through project-linked generation and storage, and how much it can rely on the grid, renewable energy contracts, and system signal response.