Contribution-driven cooperative trading strategy for multi-energy virtual power plants in the electricity-carbon coupled markets: An asymmetric Nash bargaining model

The electricity-carbon coupled markets have emerged as a pivotal mechanism for integrating renewable energy into virtual power plants and accelerating decarbonization in the power sector. With the diversification of virtual power plant types and the continued evolution of peer-to-peer trading in future energy markets, optimizing resource allocation and trading efficiency among multiple virtual power plants remains a significant challenge. This study proposes a novel contribution-driven peer-to-peer cooperative trading framework for multi-virtual power plants in the electricity-carbon coupled markets, highlighting multi-energy complementarity and low-carbon substitution. First, a contribution-based asymmetric Nash bargaining optimization model is developed by incorporating demand response and a tiered carbon trading mechanism, where each VPP's bargaining power is quantitatively determined by its marginal economic gains and emission-reduction contributions, enabling fair and incentive-compatible profit allocation. Second, the cooperative trading problem is decomposed into two subproblems to enhance computational efficiency: (1) alliance cost minimization and (2) benefit distribution. Furthermore, an alternating direction method of multipliers algorithm-based distributed solution enables coordinated optimization while preserving the privacy of individual virtual power plants. Finally, simulation studies validate the effectiveness of the proposed strategy. The results reveal that, compared to scenarios where multi-virtual power plants participate solely in the electricity market or operate independently, the cooperative approach under the proposed strategy increases benefits by ¥202.84 and ¥5,075.54, respectively, while reducing carbon emissions by 83 % and 114.69 %, respectively. Moreover, the proposed benefit allocation scheme accurately reflects each virtual power plant's contributions, ensuring fairness and sustainability in the trading process. These findings underscore the potential of the proposed model to drive low-carbon energy transitions while enhancing economic benefits, equity, and privacy.