Summary
- Nabiax intends to increase its Spanish IT capacity from 35MW to 140MW, with around €800m earmarked for expansion.
- The ADC3 project will add a third building at Alcalá de Henares and take that Madrid campus beyond 100MW.
- The operator is also examining further Madrid investment and potential expansion into Portugal, the UK, Italy, and Germany.
Nabiax is preparing an investment of around €800 million to expand its Spanish data centre capacity from 35MW to 140MW, with a third building at its Alcalá de Henares campus forming the centrepiece of the programme.
The Spanish operator plans to develop ADC3 alongside its existing facilities northeast of Madrid, taking the Alcalá campus beyond 100MW of IT capacity. Nabiax currently operates three principal facilities in Madrid and Barcelona with 35MW between them, following its evolution from a portfolio originally carved out of Telefónica.
The expansion represents a substantial step up from the existing Alcalá footprint. Nabiax’s official site lists 22.3MW of current IT power across the first two Alcalá phases, while the new business plan would push the site into a different scale of deployment and account for most of the operator’s planned capacity growth.
Chief executive Pablo Ruiz-Escribano has also indicated that Nabiax is assessing additional investment in Madrid and examining opportunities in Portugal, the UK, Italy, and Germany. The company is therefore treating ADC3 as part of a wider European growth plan rather than a standalone Spanish construction project.
Madrid capacity meets a harder power question
Nabiax’s proposed expansion comes as Spain’s data centre pipeline is spreading beyond the established Madrid market while simultaneously becoming more dependent on access to grid infrastructure. The operator’s own assessment is that Spain has generation available, but that transporting electricity to the locations where large data centre loads want to connect remains a constraint.
That distinction between electricity production and usable connection capacity has become increasingly important. A country can have strong renewable generation and an apparently favourable national energy balance while individual projects remain dependent on substations, transmission reinforcement, local distribution capacity, permitting, and connection rights.
DataCentral has already tracked that pressure elsewhere in Spain. Two Aragón projects recently surrendered 150MW of grid rights, while Madrid continues to attract large campus proposals, including Ferrovial’s planned €1 billion development in Alcobendas.
Nabiax enters that build cycle with operating assets already in the market, which reduces some of the development risk attached to entirely new campuses. Its Alcalá facilities are close to Madrid-Barajas Airport, and the site has been expanded in stages rather than arriving as a speculative gigawatt-scale proposal.
The company is targeting both conventional business colocation demand and larger hyperscale requirements. Ruiz-Escribano has also drawn a distinction between AI training campuses, which can tolerate more remote locations, and inference, cloud, and hybrid AI services where proximity to population centres and users remains more valuable.
Construction scale changes the operating model
Moving from 35MW to 140MW across the portfolio will require more than additional white space. Higher-density compute changes electrical distribution, cooling architecture, commissioning requirements, staffing, and procurement, while the schedule for major transformers, switchgear, generators, cooling plant, and grid works can determine when contracted IT capacity actually becomes usable.
Nabiax expects the construction programme to support around 1,000 jobs during development and more than 200 direct and indirect permanent roles around Alcalá once completed. Those figures remain tied to delivery of the planned investment, but they illustrate the scale change involved in moving the operator beyond its current portfolio.
The company’s expansion also sits within a more crowded Spanish market. Developers are pursuing projects in Aragón, Catalonia, Extremadura, Alicante, and the Madrid region, supported by renewable generation and growing fibre connectivity but exposed to the same problem of securing power in the right place and on the required timetable.
Merlin Properties is preparing another Spanish build in Extremadura, while a widening group of infrastructure investors and construction companies are acquiring development positions around available substations and grid capacity.
Nabiax’s €800 million programme therefore puts an established operator into the same race for electrical infrastructure, equipment, contractors, and specialised engineering capacity as Spain’s newer hyperscale developments. ADC3 may take the Alcalá campus beyond 100MW, but the usable pace of that growth will still be determined by how quickly power and physical infrastructure can be delivered alongside the building itself.
