The Nostrum Evergreen data center project in Badajoz has just cleared a new administrative step with the publication in Spain’s Official State Gazette (BOE) of the application to build the electrical substation that will connect the complex to the transmission grid. The infrastructure will have an execution budget of €12,726,868.47 and is designed to handle a 300-megawatt (MW) connection.
Nostrum Evergreen’s key facts in 20 seconds
- The BOE has opened a public information period for the SET Enlace 400/220 kV substation and a 291.96-meter overhead line.
- The infrastructure carries a budget of €12.73 million and will allow for a 300 MW connection.
- Data Riocaya, the company behind the project, has 30 business days to receive objections.
- The announced investment in Nostrum Evergreen exceeds €1.9 billion.
- State authorization is still pending: the announcement starts the procedure, not construction.
The announcement, published on September 15, 2026, corresponds to file CON-01 and covers facilities located entirely within the municipality of Badajoz. The request was filed by Data Riocaya, S.L.U., while the resolution of the prior and construction administrative authorizations falls to the Directorate-General for Energy Policy and Mines, part of the Ministry for Ecological Transition and the Demographic Challenge.
The step matters because the electrical connection is one of the infrastructures a data center of this scale needs in order to operate. Nostrum Evergreen is planned as a complex dedicated to data computing and artificial intelligence, and the project announced by Nostrum Group for its Badajoz campus exceeds €1.9 billion in investment. AECOM, which is involved in the design and construction management, also puts the investment above that figure.
A 400 kV Connection With a Line Under 300 Meters
The infrastructure now entering public review is called the SET Enlace (Substación Eléctrica Enlace) 400/220 kV, or Link Substation. Its function will be to receive electricity from the transmission grid at 400 kilovolts (kV) and step it down to 220 kV before it is supplied to the data center.
The connection to the Riocaya substation, owned by Red Eléctrica, will be made via a 291.96-meter high-voltage overhead line. The route will include two lattice steel towers and will operate as a single circuit at 400 kV.
The SET Enlace design calls for six 400/220 kV power transformers rated at 110/150 megavolt-amperes (MVA), plus room for two additional transformers that could be installed in the future. The substation will also feature 2N redundancy, designed to keep the service running if any of its main components becomes unavailable.
The state filing makes clear this is only part of the project’s electrical infrastructure. The substation’s 220 kV side and the downstream facilities that will feed the data center are not part of this state-level filing. Those elements are being processed separately before the Regional Government of Extremadura (Junta de Extremadura).
In fact, the Official Gazette of Extremadura already published in September the prior administrative authorization for the region-level facilities linked to the center’s power supply. That authorization covers the substation’s 220 kV field, two underground 220 kV lines, and the DC Badajoz 220/20 kV electrical substation.
The region-level infrastructure includes six 220/20/20 kV transformers rated at 110/150 MVA, with two more planned for a possible future expansion. The two underground lines connecting the link substation with the data center’s substation will run 3,342.74 and 3,276.91 meters respectively.
The State Filing Does Not Yet Authorize Construction
The BOE publication has a specific administrative consequence: it opens the public information period for the request for Prior Administrative Authorization and Construction Administrative Authorization for the substation and the 400 kV line.
The deadline to file objections is 30 business days, counted from the day after the announcement’s publication. Objections must be addressed to the Industry and Energy Area of the Government Delegation in Extremadura, which processes the file, while the final decision rests with the Directorate-General for Energy Policy and Mines.
This announcement therefore does not yet amount to final authorization to build the facilities. The procedure must continue until the Administration resolves the corresponding requests.
There is also a relevant detail in the file: Red Eléctrica de España granted access and connection permission for the Nostrum Evergreen consumption facility to the transmission grid at the 400 kV Riocaya substation on May 31, 2023. The formal request for the authorizations now under public review was filed with the Ministry for Ecological Transition on August 18, 2025.
The BOE also notes that the facilities covered by this filing are not subject to the ordinary or simplified environmental impact assessment procedure under the thresholds set out in Law 21/2013. Among the reasons given in the announcement itself is that the line is 291.96 meters long, well below the thresholds established for high-voltage lines under that regulation.
A Data Center Designed to Grow in Phases
Nostrum Evergreen is being developed at the Badajoz Logistics Platform and involves an announced investment of more than €1.9 billion. AECOM describes the project as a new large-scale data center selected by Nostrum Group for Badajoz, while earlier reports on the project put its planned capacity at up to 500 MW, with a smaller first phase.
The administrative documentation provides a more specific reference for the grid connection: the state filing is specifically designed for a 300 MW installation. That figure should not be confused with the full potential capacity that has been announced for the campus across its various phases.
The electrical architecture itself points to a phased rollout. The 400 kV substation reserves positions for future transformers, and the 220 kV infrastructure also includes elements that could be installed later. The design, therefore, is not limited to covering a single, closed configuration from the outset.
The project adds to a series of large data processing facilities being planned in Spain to serve artificial intelligence workloads and other high-power digital services. In Badajoz, the scale of the project makes the grid connection as significant a piece of infrastructure as the data center building itself.
For Nostrum Evergreen, the next administrative milestone will be the resolution of the state authorizations for the SET Enlace and the 400 kV line. In the meantime, the region-level portion of the electrical infrastructure already has prior administrative authorization, so both procedures are moving forward within their respective areas of jurisdiction.
The BOE publication also provides fairly precise detail on how the complex’s power supply has been designed: a 400 kV connection to the transmission grid, a 400/220 kV substation, and an overhead link of barely 291.96 meters with Riocaya. The 220 kV network that will carry electricity to the data center facilities will later be built on top of that infrastructure.
Frequently Asked Questions
How much does the Nostrum Evergreen substation cost?
The execution budget for the SET Enlace and the 400 kV line comes to €12,726,868.47, according to the filing published in the BOE.
How much power will Nostrum Evergreen’s electrical connection carry?
The state filing is being processed to connect the future data center to the transmission grid at 300 MW.
How long is the power line to the Riocaya substation?
The 400 kV overhead line will be 291.96 meters long and will connect the new SET Enlace with Red Eléctrica’s Riocaya substation.
Does the BOE publication mean the substation is already authorized?
No. The announcement opens a 30-business-day public information period as part of the procedure to obtain the prior and construction administrative authorizations.
