Environmental impact assessment of ground source heat pump system for heating and cooling: a case study in China

Purpose Ground source heat pump (GSHP) utilizes shallow geothermal energy to meet the heating and cooling needs of buildings. It has drawn global attention owing to its environmental friendliness and high energy efficiency. China ranks second and first in terms of the installed capacity and energy use of GSHPs, respectively. This study aims to explore the environmental impacts of GSHP systems in China to identify the key improvements and provide recommendations for optimizing the environmental performance. Methods The environmental impact assessment was conducted on the basis of a life cycle assessment framework with the application of the ReCiPe 2016 method. The system boundary of the investigated system was established by applying a cradle-to-gate approach and involved the installment and operational stages. The functional unit was defined as 20 years of heating and cooling by applying GSHP. Results and discussion Results showed that the potential impacts of GSHP systems were mainly concentrated in global warming and human health at the midpoint and endpoint levels, respectively. These environmental burdens were dominated by carbon dioxide emissions from the electricity generation process. Polyethylene pipe production provided additional contributions to partial categories. The comparative analysis results indicated that the energy consumption and carbon emissions of the GSHP system were reduced by 40.53% and 35.23%, respectively, in the entire life cycle compared with those of coal-fired heating and air conditioner cooling systems. Conclusions Findings of this study indicated that GSHPs could effectively reduce energy consumption and carbon emissions compared with conventional heating and cooling systems. To improve the environmental performance of GSHP systems further, applying renewable energy as electricity sources and substituting polyethylene pipes with steel pipes are suggested.