Large size heat pumps advanced cost functions introducing the impact of design COP on capital costs

Power-to-heat technologies offer low-carbon heat and integrate electricity and heating sectors. Moreover, hightemperature heat pumps can supply process heat for industries, like food, and feed early district heating networks. However, their viability is often jeopardized by high capital costs. Fluid selection affects variable and capital (TCI) costs, impacting the Coefficient of Performance (COP) and equipment sizing. Therefore, identifying the best fluid and estimating capital costs with simple and reliable cost functions are crucial for assessing heat pump market opportunities. This paper presents a multi-objective optimization, based on a detailed technoeconomic model, to find the optimal heat pump solution for different applications. Moreover, the proposed Pareto analysis is employed to derive new cost functions considering the working fluid, source/supply temperatures, and the impact of design COP on TCI, with a formulation facilitating understanding and quantification of each factor. This methodology promotes heat pump adoption in industrial electrification, especially for hightemperature applications, potentially replacing natural gas boilers. Three case studies demonstrate the robustness of the approach to assessing capital costs, showing low deviation (<8%) between the detailed technoeconomic model and the fast-to-applicate new cost functions. The innovative cost functions ensure easy but accurate assessments, fostering confidence in transitioning to heat pump solutions.