EnergyRocks – heat storage in a rock bed

Watch Kurt Engelbrecht explain the EnergyRocks project.

The EnergyRocks project examines how to transform surplus electricity from wind into heat and then store it in a rock bed. The purpose is to decarbonize heat processes in industrial heating at GreenLab. More specifically, the research team wants to develop a design for a rock bed thermal energy storage for a 40 MW heating process. 

Finalised project result:

The existing thermal storage design was improved for the purposes at Greenlab. Based on a developed techno-economic optimization tool applied for the process heat demand of 40 MWth, a theoretical analysis led to a system with 1 GWhth total storage capacity and a heater power of 60 MWel. A practical analysis using production and consumption data from GreenLab showed that this sizing is well suited for the process heat supply but more electricity is needed, either by importing or by increased production on-site when prioritizing electrolysis and the overall park consumption. Using the developed CFD model, key design aspects such as charge temperature, storage material and particle size were specified.

Kurt Engelbrecht (Associate professor at DTU Energy):
“With the SymbiosisNet, GreenLab Skive has created a highly useful framework for developing and demonstrating sector coupling concepts. The park brings together researchers and companies in a way that can spur new ideas for best utilising the resources available in the park toward the processes that are running there. Having renewable electricity production, a range of industrial processes and a connection to the district heating network, the park has the most important building blocks for developing innovative concepts with the possibility to implement and test them.”

Kai Knobloch (PhD student at DTU Energy):
“What I liked most about working with GreenLab is how they facilitate research and innovation. The fast-paced, mission-driven approach with a series of defined challenges is a great addition to traditional academic research. GreenLab really forced me to think holistically in order to exploit all synergies on site and is a unique place to test theories at scale, in particular for young researchers. The open dialogue within the community, including various interesting site visits, caps it all off!”

Primary publications:

Y. Muhammad, P. Saini, K. Knobloch, H. L. Frandsen, K. Engelbrecht. Rock bed thermal energy storage coupled with solar thermal collectors in an industrial application: Simulation, experimental and parametric analysis. Journal of Energy Storage (2023). Under review.

K. Knobloch, J. Weiss, T. Fluri, K. Engelbrecht. Power-to-Heat for Industry: Economic Operation Optimization of a Molten Salt and Packed Bed Thermal Energy Storage. Energy (2023). In preparation.

Funding Agency: