Life cycle sustainability assessment of ground source heat pump in Shanghai, China

• A sustainability evaluation method based on Life Cycle Theory is designed.
• This new method is tested in a case study on Ground Source Heat Pump in China.
• Our innovated method gives a more comprehensive and concise view of the measures assessed.
• The evaluation ideas provide reference for assessment of other energy saving measures.

The growing worldwide demand for Greenhouse gas (GHG) emission reduction has led to a new age of energy saving. Besides the energy saving extent, the costs of energy saving measures as well as the environmental and social impacts are also necessary to be evaluated in order to make sure that the application of these measures can also meet sustainable development requirements. Thus, a sustainability evaluation method based on Life Cycle Theory is innovatively designed in this study. We present its new aspects, describe its working steps in detail and also test this new method by means of a case study on Ground Source Heat Pump (GSHP), which is a renewable technology that is widely applied in the building sector in China. Data for the case study is collected by literature review and site investigation. Results show that the energy consumption of the investigated GSHP cases has an energy saving rate as around 40.2%.The main environmental impacts of GSHP are found to be global warming, acidification and eutrophication in the production process, and soil temperature change in the operation process. The prevention cost of the environmental impacts is around 15.84 RMB/m2 in the production process, and 5 RMB/m2 in the operation process. The payback time of our cases is around 4 years, and it will rise to 4.29 years if accounting the environmental prevention cost. We conclude based on the case study that our assessment method proofs to be useful as it can demonstrate comprehensive characteristics of sustainability for energy saving measures in the whole life cycle.