Which combinations of renewable energy policies work better? Insights from policy text synergies in China

Policy synergy is crucial to achieving unified national strategies in the effective implementation of policy. This study investigates the synergistic effectiveness of China's renewable energy (RE) policy tools by analyzing 7920 RE policy texts issued by provincial governments between 2005 and 2020. By proposing the “Policy Text Quantification-Association Rule Mining-Synergy Effect Test” framework, we explore how the interaction between five policy tools affects Chinese provincial RE development. Results show that provincial policy texts mainly use targets & planning and industrial development with lower stringency than the other three tools. More importantly, targets & planning policies interact positively with operations management and industrial development, as they help reduce the uncertainty during concrete implementation in achieving expected targets and plans. On the other hand, industrial development and financial support policies could potentially repeat incentives on specific industries or enterprises, amplify unequal resource allocation and market distortion, failing to generate synergy effects.