Evaluation of the environmental sustainability of a Stirling cycle-based heat pump using LCA

Heat pumps are increasingly seen as efficient and cost-effective heating systems also in industrial applications. They can drastically reduce the carbon footprint of heating by utilizing waste heat and renewable electricity. Recent research on Stirling cycle-based very high temperature heat pumps is motivated by their promising role in addressing global environmental and energy-related challenges. Evaluating the environmental footprint of a heat pump is not easy, and the impacts of Stirling cycle-based heat pumps, with a relatively high temperature lift have received little attention. In this work, the environmental footprint of a Stirling cycle-based very high temperature heat pump is evaluated using a “cradle to grave” LCA approach. The results for 15 years of use (including manufacturing phase, operation phase, and decommissioning) of a 500-kW heat output rate system are compared with those of natural gas- and oil-fired boilers. It is found that, for the Stirling cycle-based HP, the global warming potential after of 15 years of use is nearly −5000 kg CO₂ equivalent. The Stirling cycle-based HP offers an environmental impact reduction of at least 10% up to over 40% in the categories climate change, photochemical ozone formation, and ozone depletion when compared to gas- and oil-fired boilers, respectively.