THUNDER

THUNDER aims to develop sustainable waste heat recovery and seasonal storage solutions for data centres in urban areas. The goal is to supply heat to nearby district heating networks while also providing a cooling service to the data centres. The project focuses on thermochemical material (TCM)-based storage systems. These innovative systems use advanced materials selected to maximise storage capacity by improving heat and mass transfer and minimising thermal losses.

When combined with thermal upgrade devices such as high-temperature heat pumps, these TCM systems—based on chemical reactions and sorption processes—offer a next-generation, compact, and efficient storage solution. They can effectively capture low-grade waste heat from data centres during the summer, store it, and release it into district heating networks in winter.

The effectiveness of TCM storage for recovering waste heat from data centres will be evaluated in real conditions at the Varna demo site in Bulgaria, focusing on environmental, economic, and energy impacts.

THUNDER’s ultimate objective is to demonstrate an efficient waste heat recovery system that connects data centres with urban district heating networks. The system combines seasonal thermal storage (STS) strategies with innovative heat pump technologies, enabling efficient energy transfer and storage. This integrated approach enhances the reuse of waste heat in an energy-efficient, sustainable, and cost-effective way, bridging the gap between heat production and demand.

Importantly, this solution helps address urban overheating by turning excess summer heat—often a burden in dense cities—into a valuable energy source. In doing so, THUNDER not only contributes to renewable energy use but also to more resilient and climate-friendly urban infrastructure.

Funded by: Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or CINEA. Neither the European Union nor CINEA can be held responsible for them.