Dynamic modeling and coordinated multi-energy management for a sustainable biogas-dominated energy hub

Abstract

Low renewable energy source (RES) accommodation and energy utilization efficiency impose great challenge to reliable energy supplies for rural residents. This paper proposes an optimal coordinated multi-energy conversion and management framework with a biogas-dominated hybrid renewable microgrid for multi-carrier energy supplies in off-grid remote areas. In this framework, multi-energy multi-timeframe couplings among biomass and other renewables are modeled based on biogas digesting thermodynamics for the coordinated interaction among electricity, biogas and thermal energy carriers, and a sustainable energy hub is formulated for mapping various renewables into diversified energy loads. The proposed energy hub can facilitate mitigating the fluctuating outputs of RES by harvesting hydro-wind-solar energies into the form of biogas, and an evaluation model is proposed based on hydrodynamic networking mechanisms to calculate the state of energy (SOE) in the biogas storage. Furthermore, a hierarchical multi-energy management strategy is presented to dynamically optimize the production, conversion, storage and consumption of multi-carrier energy flows for system energy-efficiency enhancement. Case studies on a stand-alone microgrid demonstration validate that the biogas yield can be improved by 31.75% with digesting thermodynamic effects, and the battery degradation cost can be reduced by at least 22.63% considering the SOE of biogas storage with hydrodynamic effects.