Life Cycle Assessment of China's High Speed Rail Systems
China has built the world’s longest network of High Speed Rail (HSR) systems in less than 5 years. However, there are very few studies on the life cycle impact of China’s HSR systems compared to studies around the world. Environmental impacts of China’s HSR could be very significant due to dependence on dirty coal-fired power and material and energy intensive bridges. Thus, a life cycle assessment of China’s HSR systems is necessary.
Life Cycle Assessment (LCA) is used to investigate environmental impacts of China’s HSR system between Beijing and Shanghai, assessing life cycle stages including: (1) vehicle manufacture, maintenance, and disposal; (2) infrastructure construction; (3) operation. Data from Chinese Ministry of Railway, Ecoinvent database, and Chinese Core Life Cycle Database (CLCD), are compiled to build the HSR’s life cycle inventory. LCA software eBalance is used to conduct the analysis. Additional scenarios are developed by varying infrastructure composition, electricity mix, HSR development, travel length of cross-line vehicles, vehicle utilization, occupancy rate, and use of fly ash in concrete, in order to help identify major drivers of environmental impact and propose recommendations for improvement.
It is discovered that operation stage contributes to 72-91% of the impacts in Acidification Potential (AP), Primary Energy Demand (PED), Eutrophication Potential (EP), Global Warming Potential (GWP), and Respiratory Inorganics (RI). Vehicle stage contributes to 43% of impact in Chinese Abiotic Depletion Potential (CADP). Infrastructure construction accounts for 54% of impact in Chemical Oxygen Demand (COD) and 38% of impact in CADP. Scenario analysis identified several key drivers of impact, including proportion of bridge, tunnel, and reinforced subgrade, electricity mix, various factors that lead to different demands of HSR vehicle and transportation, and fly ash use in concrete. Several suggestions are proposed to improve life cycle environmental performance of HSR projects. It is also discovered that China’s HSR systems have higher impact in RI than Germany’s HSR and conventional rail systems, and lower impact in RI than Switzerland’s road and air systems.