Data centre waste heat recovery through thermochemical energy storage and high temperature heat pump: preliminary analysis

Despite significant advancements in waste heat recovery from data centre cooling processes, several challenges persist, particularly concerning seasonal storage and the spatial mismatch between heat sources (data centres) and potential end-users, which often prevents direct connections, limiting the feasibility of conventional heat recovery solutions. The THUNDER Horizon EU project ("THermochemical storage Utilization eNabling Data centres seasonal Energy Recovery"), aims to bridge this gap by developing an pioneering way to store the waste heat during summer in an interseasonal thermochemical energy storage and reusing it to feed a district heating network during winter; the challenges associated with the spatial mismatch is addressed by implementing an innovative way to transport waste heat on wheels. The research, conducted by the ThermoGroup at the Department of Industrial Engineering, consists of an initial experimental and analytical phase, followed by the development of a demonstration site in Varna, Bulgaria. The study employs thermodynamic modelling, laboratory-scale experiments, and numerical simulations to assess the system’s performance. This paper presents the conceptual design of the THUNDER project, focusing on its two principal subsystems: the thermochemical storage unit and the high-temperature heat pump, which is essential for achieving the required desorption temperatures during the charging phase. Preliminary results indicate promising thermal performance, with ongoing studies aimed at system optimization and real-world feasibility assessment. Future work will focus on enhancing operational efficiency, scalability, and techno-economic feasibility to enable broader adoption in district heating and industrial applications.