Evaluation Method for Carbon Emission Reduction Benefits of Renewable Energy Considering the Coupling of Electricity and Carbon Markets

With the rapid development of electricity–carbon markets and global renewable energy deployment, accurately quantifying and fairly compensating carbon reduction benefits of energy has become crucial for low-carbon energy transformation. Current methods suffer from mechanism, price signal fragmentation, and unclear carbon responsibility attribution. To address these challenges, this paper proposes a novel renewable energy carbon emission reduction benefit evaluation method considering electricity–carbon coupling. Firstly, a Copula-based methodology to construct typical electricity–carbon price scenarios is developed, revealing significant correlation between electricity and carbon prices (Spearman coefficient: 0.730, Kendall coefficient: 0.620). Second, a power dispatch model incorporating BEKK-GARCH-based price linkage analysis is established, quantifying the coupling risk coefficient at 0.54. Third, an improved Shapley value method with correction factors including responsiveness, output stability, and marginal carbon reduction benefits is introduced to accurately evaluate renewable energy contributions. Case study results demonstrate that the proposed method achieves 20.3% system cost reduction, and 7.10–9.90% carbon reduction improvements with energy storage. Practical testing directions include pilot implementations in regional power grids followed by scaling to larger networks, with subsequent applications in regulatory carbon market design, utility optimization planning, and renewable energy project evaluation. This work provides essential tools for global electricity–carbon market integration and carbon neutrality achievement in power systems.