Assessing the provincial renewable energy generation efficiency in China considering the energy justice and sustainable development

The rapid increase in renewable energy (RE) installed capacity and the resulting issues of energy justice and RE generation efficiency (REGE) require urgent attention. Therefore, this study calculated the China's RE justice indexes (REJIs) and the provincial RE justice contribution degree from 2012 to 2021 via the Gini coefficient and modified coupling cooperation degree model. Hydropower, wind, and solar power generation efficiencies (HPGE, WPGE, and SPGE) were evaluated using the super-efficiency slack-based measure model. The results show that the REJIs of wind and solar power demonstrated an increasing trend, whereas that of hydropower slowly declined in the following order: wind power > solar power > hydropower. The HPGE fluctuated without remarkable change. The WPGE and SPGE gradually increased, but the SPGE increased rapidly. Furthermore, the Global Malmquist-Luenberger productivity index results revealed that the HPGE and SPGE were driven by efficiency change (catch-up effect), whereas the WPGE was driven by technical change (innovation effect). The REGE exhibited considerable regional heterogeneity. It was the highest in Western China, followed by that in Central China, and the lowest in Eastern China. Our findings can guide policymakers in improving policies to enhance REGE and promote just and equitable energy transition development.