Use Case 1: Key Results

Key results from the implementation of RESTORE  Use-Case 1, Brønderslev, Denmark, are summarized and categorized as follows:

Specific conclusions about integration and feasibility

• Seasonal valorization of non-utilized solar thermal energy. Use-Case I has identified the possible storage of approximately 5.46 GWh/year that is currently not utilized by the facilities and means seasonal mismatches between supply and demand.
• Strong compatibility between PTC field and TCES requirements. The average thermal oil temperature (146.5 °C) and mass flow (72.1 kg/s) fall within the optimal range for charging the CuSO₄·5H₂O-based TCES reactor, confirming direct integration feasibility.
• TCES reactor sizing and cycles supported by RES profiles. Detailed monthly profiles and unutilized energy curves allowed for the definition of reactor capacity, charge/discharge timing, and expected cycle frequency.
• Full-year dynamic simulation demonstrates operational viability. The IPSE GO model successfully simulates 987 hours of charging and 700 hours of discharging, confirming that the TCES system can be operated consistently within real plant conditions. Noting that TCM reactions have different energy in play.
• ORC integration validated with detailed thermodynamic modeling. Simulated ORC performance shows net efficiency of 4.61%, turbine inlet/outlet flow consistency, and realistic pressure ratios — confirming proper coupling with the TCES discharge cycle.

 General conclusions

• Brønderslev selected as a candidate for RESTORE concept. High renewable penetration, presence of a flexible DH network, and non-utilized solar thermal energy make Brønderslev a highly suitable site for RESTORE integration and demonstration.
• RESTORE approach enhances dispatchability of solar thermal. The TCES solution enables solar energy to be decoupled from real-time demand, increasing system flexibility, improving renewable integration, and reducing curtailment in hybrid plants.