Environmental synergies and trade-offs in low-carbon transition of power sector: A life cycle assessment of various power generation technologies in China

The power sector's low-carbon transition underpins societal carbon neutrality. Corresponding environmental impacts are often neglected. Herein, a comprehensive life cycle assessment is conducted for conventional coal-fired power (CFP) and four typical low-carbon technologies, including co-firing biomass with coal (CFP-B), coal-fired power with carbon capture and storage (CFP-CCS), wind power (WP) and photovoltaic power (PV). Results show that all low-carbon technologies reduce overall environmental impact and carbon footprint. Compared to that of CFP (815.3 g CO2 eq/kWh), the carbon footprints of CFP-B, CFP-CCS, WP and PV are reduced by 16.6%, 74.7%, 99.2%and 95.3%, respectively. However, PV has the largest impact on abiotic depletion, while CFP-CCS exhibits the greatest human toxicity, acidification and eutrophication effects. The environmental impacts of coal-based technologies are primarily concentrated in the power generation and upstream coal mining stages. Biomass usage increases the proportion of acidification and eutrophication in power generation stage due to its chemical property. CCS has no benefit in the environmental impacts except for global warming because of increased energy and source consumption. The environmental impacts of WP and PV are largely concentrated in the equipment manufacturing stage, although these impacts are partially offset by resource recycling. The main source substances contributing to environmental impacts are identified. Environmental burdens are influenced by parameters such as biomass type and electricity mix. PV exhibits a cross-elasticity coefficient of −10.3, indicating a substantial trade-off between global warming and abiotic depletion. This study clarifies potential environmental risks in power decarbonization, supporting stakeholders in formulating sustainable development policies.