Evangelos Bellos
High temperature heat pumps (HTHPs) are critical technologies for industrial electrification and decarbonization. This work investigates an innovative configuration that produces useful industrial heat in the range of 200 °C to 300 °C, driven by electricity and low-grade waste heat in the range from 90 °C to 130 °C. Specifically, the present work studies a cascade HTHP which includes an absorption heat transformer with LiBr/water working pair in the low-stage and a water/steam mechanical compression heat pump in the upper stage. The system is optimized aiming to maximize its exergy efficiency. The analysis is conducted with a developed and verified model in Engineering Equation Solver. The results showed that the suggested system outperforms other HTHPs according to the literature evidence. The reported system coefficient of performance is found to range from 1.81 to 9.41, while the exergy efficiency ranges from 58.78% to 66.24%. Also, a comparative analysis with a conventional natural gas boiler, the environmental and economic superiority of the suggested examined system was reported. Specifically, the levelized cost of heating for the boiler case was found to be 0.1017 €/kWh, while that of the present system was in the range of 0.0372 to 0.0876 €/kWh. • Cascade HTHP delivers industrial heat at 200–300 °C using electricity and waste heat. • System integrates LiBr/H₂O absorption and water/steam compression heat pump. • Exergy-optimized design achieves efficiencies up to 66.24%. • Coefficient of performance ranges from 1.81 to 9.41. • Levelized heating cost is up to 63% lower than a natural gas boiler.