Electrification and decarbonization of industrial process heat is an important next step in the energy transition to reduce greenhouse gas (GHG) emissions. This study provides an in-depth analysis of how in the current industrial landscape the combination of commercially available electric heating technologies with the implementation of thermal energy storage (TES) can realize the electrification of
medium-temperature industrial process heat on the short-term. Moreover, it explores what potential novel high-temperature heat pump (HTHP) technologies, specifically the supercritical CO2 (sCO2) reversed Brayton HTHP, have to realize this electrification even more efficient in terms of electricity demand in the future. Thereby, it also briefly highlights the opportunities and challenges to combine HTHP technology and TES in the future to realize an optimal electrification.

To improve the efficiency of domestic heat energy use, a heat battery was added to a boiler. This heat battery contains a phase change material (PCM) characterized by low thermal conductivity and high specific heat, enabling efficient storage of residual heat energy. Paraffin wax was selected due to its high latent heat storage capacity; however, its low thermal conductivity posed challenges regarding storage time. To address this, a finned tube was introduced, and the feasibility of the heat battery for domestic applications was investigated. The effectiveness of the finned tube was evaluated using both a numerical model and an experiment. In the experiment, a temperature- and flow-adjustable water source was connected to a plain tube and a finned tube, with temperature and heat flux measurements recorded to assess the impact of the fin structure. These conditions were replicated in the numerical model for comparison. The results indicated that heat extraction from the PCM using the finned tube required approximately 60 minutes, compared to nearly five hours with the plain tube. These findings suggest that while the method shows promise, further development is needed before it is suitable for domestic implementation.