Summary
- The proposed CDC San Mateo campus would occupy about 122 hectares and target 570MW over four phases.
- Its documented initial grid access is 80MW at Peñaflor and 10MW at Villanueva de Gállego.
- Proposed cooling options and river water arrangements need further assessment, with no full-campus consumption figure.
A proposed data centre campus near Zaragoza is targeting 570MW of electricity capacity, but the development documentation identifies access rights for only 90MW in its initial phase. The difference places future network capacity at the centre of the project’s delivery schedule, alongside unresolved cooling and water requirements.
The CDC San Mateo proposal is associated with O-Green, an investment group linked to Oman, and local interests including Desarrollos Ecoindustriales La Cartuja. Reporting on 20 October identified a revised development structure replacing an earlier arrangement involving Vantage Data Centers in the Zaragoza area.
The planned site lies at San Mateo de Gállego, south of the Río Gállego 1 industrial estate. The development is described as covering approximately 122 hectares and accommodating seven buildings across four phases, with a projected investment of around €7.4 billion.
Those figures describe the proposed full programme, not a committed construction expenditure or completed facility. The available information does not demonstrate that all of the estimated investment has been raised, contracted or allocated to construction.
The first phase is associated with grid access for 80MW at the Peñaflor substation and 10MW at Villanueva de Gállego. Additional power requests remain outstanding. Even if the applications described in the project documentation were approved, they would not necessarily provide the 570MW required by the full campus.
Developers of large computing facilities must distinguish a request for electrical capacity from an approved connection and an energised supply. Each involves a different stage of development and may require equipment, grid reinforcement, technical studies and contractual commitments before servers can begin operating.
The project has an initial operational ambition around 2029. Later phases will depend on both customer demand and the availability of further electricity. That is more conditional than a simple construction schedule suggesting all 570MW will be delivered in a fixed programme.
Power demand will also affect how the site is organised. Several data centre buildings need a practical arrangement for receiving, transforming and distributing electricity while supporting backup infrastructure and equipment maintenance. A campus capable of supporting very large AI loads may require staged substations and electrical systems whose commissioning is coordinated with the installation of computing equipment.
Cooling has not yet been resolved to a single technology. Project information considers dry, hybrid and evaporative systems, depending on the requirements of eventual customers. These approaches have different water, electricity and heat rejection characteristics, especially in the hot conditions that can occur in Aragón.
Dry coolers reject heat to ambient air and generally avoid continuous evaporative water replacement, but the temperature of outdoor air affects their performance. Evaporative approaches can change the heat rejection balance while requiring managed water supplies, treatment and discharge arrangements. Hybrid systems combine operating modes, with site-specific benefits that depend on how they are controlled.
The documentation considers drawing water from the Gállego River and identifies about 225 cubic metres per day for the initial phase. It does not provide an equivalent total for the completed 570MW campus. A full-campus figure cannot be derived reliably by simply scaling the initial requirement, because equipment density, cooling design and operating profiles may change between phases.
Water abstraction and discharge may require additional assessment and authorisation. The design must explain how cooling systems would operate during low river flows, high ambient temperatures and other conditions that influence the ability to reject heat.
The proposal has entered preliminary consultations intended to define the scope of its strategic environmental assessment. Those consultations address the campus and supporting power and fibre infrastructure across nearby municipalities. The promoters also await a regional decision on whether the development will be designated an investment of regional interest.
The existing environmental process is not a newly granted construction approval. Much of the substantive project information was public in Spanish reporting by 20 October; English-language reporting on 23 October added accessibility, not a later planning decision.
The scheme also follows an earlier development associated with Vantage and another Zaragoza-area location. Treating that older project and the revised San Mateo proposal as separate fully financed campuses would overstate the committed investment and infrastructure pipeline.
The next phase depends on securing additional electricity, specifying the cooling system and establishing permissible water use. The reported 570MW target remains conditional on those requirements and on the customer commitments needed to justify construction. The proposed 570MW scale remains a target until those dependencies are resolved.
