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High-temperature heat pumps: market overview, state of the art, and application potential
1OST - Eastern Switzerland, University of Applied Sciences, Institute for Energy Systems, Buchs, Switzerland.
Abstract:
High-temperature heat pumps (HTHPs) are a key technology for enabling the decarbonization of industrial process heat up to about 200 °C and for generating steam. This paper reviews the state of the art in HTHP technologies, presents case studies from Europe, and discusses their potential applications in New Zealand. Industrial sectors such as dairy, food processing, and chemicals are identified as particularly relevant due to their substantial demand for low- to medium-temperature heat. Case studies from European demonstration projects demonstrate the successful integration of HTHP, achieving coefficients of performance (COP) ranging from 2.5 to 4.5 under varying operating conditions, while delivering significant energy savings and CO₂ emission reductions. The transition to natural refrigerants, large-scale demonstrations, and supportive policy frameworks emerge as critical enablers. Economic feasibility is strongly influenced by market dynamics, particularly the ratio of electricity to fossil-fuel prices and the CO₂ intensity of the electricity supply. Environmental regulations also significantly influence refrigerant availability and system design choices. Technical challenges remain in compressor design, refrigerant selection, and efficiency limitations associated with large temperature lifts. The analysis highlights three priorities for accelerating market adoption: (A) greater dissemination of knowledge about the integration of HTHPs in industrial processes, (A) increasing the availability of low-global-warming potential (low-GWP) refrigerants, and (B) improving the cost-competitiveness of electricity relative to fossil fuels. With these developments, HTHPs can play a central role in sustainable industrial energy transitions.
Graphical Abstract:
Evolution of the high-temperature heat pump (HTHP) market from 2018 to 2024, showing the growing number of HTHP suppliers, categorized by maximum heat supply temperature, heating capacity (logarithmic), and compressor technology (colors) (Figure credit: C. Arpagaus, OST).
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