SOCOTEC oversees the groundbreaking Bogatell Cold Generation Plant in Barcelona, Spain

This pioneering facility is designed to harness seawater for the production of high-efficiency cooling, marking a major milestone in the city’s ongoing energy transition.

As part of Districlima’s urban heating and cooling distribution network, the plant plays a key role in advancing decarbonization and energy efficiency in urban settings.

Districlima is Barcelona's pioneering urban heating and cooling network, established in 2002. It's a public‑private partnership (led by ENGIE, TERSA, AGBAR, and the Spanish energy agency IDAE) that distributes both heat and cold efficiently across the city

Once operational, the plant will increase the number of buildings connected to this sustainable technology by 33%, expanding Barcelona’s air-conditioned area from the current 1,700,000 m² to 2,496,494 m² by the end of the first two phases in 2032.

This expansion is equivalent to supplying heating or cooling to a 250-block area in the Eixample district, at the heart of Barcelona, underscoring the significant environmental impact the project will have on the city.

An Underground engineering feat: constructing the central facility

One of the most technically demanding elements of the project was the construction of the underground central building. Spanning 2,780 m² with a perimeter of 240 meters, the structure required the excavation of 30,414 m³ of material and the use of advanced civil engineering solutions to ensure safety, stability, and efficiency.

Key construction features included:

• Perimeter diaphragm walls reaching depths of 20 to 24 meters, with cross sections of 0.8 x 3.6 m and 0.6 x 3.6 m
• A two-level anchoring system comprising 277 anchors with a total length of 7,625 meters
• An underpressure foundation slab supported by 24/18 m-long screen wall modules
• A prefabricated internal structure, including slabs and the roof
• A total of 5,203 m³ of diaphragm wall (80 cm) and 1,606 m³ (60 cm)
• The use of 1,768,500 kg of steel

This phase of the project stands out not only for its scale and complexity, but also for the precision and innovation required to build below ground in an urban coastal environment.

Innovative seawater intake system

The Bogatell Cold Generation Power Plant features a state-of-the-art seawater intake system that marks a significant advancement in coastal infrastructure engineering.

Designed to operate efficiently in a dense urban and marine environment, the system includes a 659-meter-long microtunnel that transports seawater to the facility for sustainable cooling production.

This microtunnel has an outer diameter of 2.2 meters and an inner diameter of 1.8 meters, and is divided into two main segments:

• 240 meters beneath land
• 419 meters extending offshore under the seabed

Its construction navigates complex geological and environmental conditions along Barcelona’s coastline.

To carry out this challenging task, engineers employed a HERRENKNECHT 1800 TB closed-shield microtunnel boring machine, equipped with advanced features including:

• Seven thrust stations
• Hyperbaric chamber modules
• A marine rescue module

This cutting-edge machinery enables precise, safe excavation while significantly reducing the environmental impact on the marine ecosystem.

The tunnel's alignment—featuring curves both horizontally and vertically—showcases the system’s flexibility and its ability to adapt to the region’s demanding topography and urban constraints.

SOCOTEC Spain´s expertise in energy infrastructure

SOCOTEC is a recognized leader in project execution, construction management, and commissioning of power generation facilities. Its involvement in the Bogatell Cold Generation Plant in Barcelona highlights its capability to tackle complex challenges within the energy sector.

The company’s multidisciplinary team conducts a wide array of essential studies, including geotechnical investigations, risk assessments, excavation planning, hydrogeological and geophysical analyses, as well as marine climate and thermal dispersion evaluations.

This broad expertise enables SOCOTEC to deliver innovative, sustainable solutions that ensure technical viability, operational efficiency, and full environmental compliance across renewable energy projects, thermal plants, and urban district cooling systems. From early concept design through to final commissioning, SOCOTEC provides deep industry knowledge and a comprehensive approach to every phase of the project lifecycle.