Nash bargaining-based game for transactive energy of multi-microgrids with dynamic carbon emission factor

Transactive energy is a popular technique to achieve energy trading and sharing among different power agents, as well as for different connected microgrids. It can dramatically improve operational flexibility and the benefits for each microgrid. However, numerous studies of transactive energy have paid more attention to the energy cost, which have failed to take carbon emissions into account. Furthermore, it was assumed that the carbon emission factor (CEF) per kWh of electricity is fixed, which cannot reflect the electricity variation from different generations. As a result, the low-carbon operational flexibility is highly insufficient. To address these issues, this paper proposes a transactive energy mechanism for multi-microgrids with dynamic CEF. Unlike traditional fixed CEF approaches, the dynamic CEF can directly reflect the electricity combination from different power sources. To adapt to the charge–discharge dynamics, a calculation model of CEF is designed for the energy storage systems. Besides, a Nash bargaining-based game with alternating direction method of multipliers is introduced for transactive energy, which can enable deep cooperation among microgrids. To further enhance transaction feasibility and fairness, a fair benefit distribution mechanism is developed among microgrids according to their transaction volume contributions and roles. Finally, case studies show that the proposed technique significantly reduces the operational cost for participating microgrids by 19.4%, 12.9%, and 38.7%, respectively. The role-adaptive benefit allocation mechanism achieves equitable distribution by aligning profits with each participant’s contribution; for instance, the microgrid with the highest contribution achieves a maximum absolute cost reduction of 2,354.8 CNY, validating a more reasonable outcome compared to standard Nash models. • A transactive energy mechanism for multi-microgrids with dynamic CEF. • A generalized Nash bargaining-based game enables deep cooperation among microgrids. • A role-based profit distribution mechanism ensures fairness. • The model enhances cooperation among multi-microgrids and lowers operating costs.