Vattenfall, the Swedish energy utility, had demonstrated significant interest in these data center developments from an early stage and facilitated a partnership with VB Energi, the local district heating provider in Fagersta, Sweden. The primary objective of this proof-of-concept was to validate simulated parameters, specifically flow rates and heat output, within a live environment. The goal was to produce CO2-neutral waste heat, known in Sweden as “spillvärme,” to support the decarbonization of the heating industry.
Despite the small footprint of the mobile data centers, the planning process remained focused on efficiency and sustainability. This involved securing all necessary permits and conducting environmental assessments to ensure the site’s suitability for the Digital Heat Plant (DHP). The site preparation began with the installation of the district heating and electrical connections. Due to Nordic weather conditions, ground excavations were strategically timed for the spring thaw. The technical setup followed, involving the installation of hundreds of servers and the integration of the liquid-cooling systems. Although hydro-engineering presented a new technical challenge, intensive research into piping and pressure dynamics ensured a successful implementation.
The construction phase proceeded according to schedule, culminating in the successful activation of the facility. The system achieved its target of capturing nearly 99% of waste energy and transferring it directly to the local district heating network. Since the successful validation of this concept, the first two DHPs have remained operational in Fagersta. This proven real-life application has provided the foundation for expanding operations into new cities, regions, and international markets.
