Optimal energy trading in rural micro-grids with variable ownership of photovoltaics and power stations: A Stackelberg game approach

China's over-reliance on fossil fuel for rural energy use leads to significant health and environmental problems. Establishing rooftop photovoltaic-based rural micro-grids energy system is an effective way to reduce both pollutant and carbon emissions from rural energy use. However, the complex operational strategy and variable ownership of rural micro-grids make it challenging to motivate farmers to participate in micro-grid scheduling and realize a reasonable distribution of benefits. Here we propose a Stackelberg game-theoretic framework for the one-to-many leader-follower competitive cooperative relationship between power stations and farmer households in rural micro-grids. The objective function is then solved based on the Karush-Kuhn-Tucker condition and dyadic transformation to obtain the micro-grid trading strategy at the Nash equilibrium point. The results show that the dynamic tariff mechanism enhances the smoothness of the interaction of the rural micro- grids with the main grid 5 times higher compared to the results obtained with fixed tariff scenarios. The annual revenue of the rural micro-grid also increases in the dynamic tariff scenario, while realizing a reasonable distribution of benefits among different ownership types within the micro-grid. This study provides a theoretical basis for trading strategies while improving the investment attractiveness of rural PV microgrid systems.