Co-benefits of wind and solar power deployments for air pollutants and carbon emissions reduction in Guangdong Province of China.

Wind and solar power are widely regarded as key pillars of clean transition owing to their promising development potential. Systematically evaluating the environmental benefits of wind and solar power deployments is essential as it can enhance their social acceptance and support sustainable development. In this study, we first evaluated emissions reduction driven by wind and solar power deployments in 2022 in Guangdong Province, China's most populous province with the highest electricity demand. Then, with atmospheric transport model, we assessed impacts on air quality and CO2 concentrations due to emissions reduction. Finally, we monetized environmental co-benefits by quantifying health benefits and carbon reduction benefits. Our results indicated wind and solar power deployments significantly reduced air pollutants and CO2 emission from the power sector, with the extent of reductions jointly determined by regional renewable generation and the emission intensity of displaced thermal power. Emissions reduction contributed to improved air quality and lower CO2 concentrations, with provincial average CAQI and surface-level CO2 concentrations decreasing by 0.84 % and 0.53 ppmv, respectively. PM2.5 and O3 pollution mitigation avoided 388 (95 % CI 290-485) premature deaths, delivering $268 million health benefits. In parallel, CO2 emissions were reduced by 2.53 × 104 kt, yielding $141 million carbon reduction benefits. Altogether, these environmental co-benefits were equivalent to $12.07/MWh, covering 16-45 % of the LCOE for wind and solar power, which underlined the out-of-market societal benefits. This study offered valuable insights for policymakers to aim at optimizing clean transition policies for achieving integrated environmental, health, and climate objectives.