Benefit allocation and pricing mechanisms in renewable-thermal energy coalitions

China's rapid transition toward renewable energy has created increasing demand for efficient benefit allocation and pricing mechanisms capable of balancing economic growth, energy security, environmental sustainability, and stakeholder profitability. The integration of renewable energy sources into power grids creates operational challenges due to output variability. This study develops a cooperative game-theoretic framework for coordinating renewable and thermal power producers to optimize energy utilization, enhance grid stability, and distribute benefits equitably. The framework employs the Shapley value method for coalition surplus allocation, incorporating time-of-use pricing across peak, flat, and trough periods. A mathematical formulation integrating deviation-cost assessment, ramping constraints, and temporal capacity contracts simulates market transactions among coalition members. Results show that the cooperative strategy increases renewable energy consumption by 1.35 MWh (22.32%), reduces deviation assessment costs by 51.33 yuan/day, and generates incremental daily revenues of 547.12 yuan for renewable producers and 696.34 yuan for thermal producers. The total coalition benefit reaches 1192.13 yuan/day, confirming the economic viability of the integrated approach. Scenario analysis under uncertainty, including renewable generation variability (CV = 25%), demand shocks (±15%), and electricity price volatility (±20%), confirms the framework's stability, with cooperative arrangements maintaining positive coalition surplus in over 96% of Monte Carlo simulations. The framework advances United Nations Sustainable Development Goals 7 and 13 through improvements in renewable energy utilization and reductions in carbon emissions. These findings offer practical guidance for policymakers seeking to accelerate China's energy transition toward carbon peaking by 2030 and carbon neutrality by 2060.