Optimizing Microgrid Efficiency: A Methodological Approach to Scheduling Combined Heat and Power Systems With Renewable Energy Sources and Diverse Battery Technologies

Abstract

The escalating reliance on renewable energy sources (RES) is revolutionizing microgrids (μGs), making coordinated scheduling of these systems not just beneficial but essential for optimizing efficiency and meeting electrical load demands effectively. This study addresses the scheduling challenges of combined heat and power (CHP) systems, proposing a methodology that meets the total heat and power demands of microgrids (μG) while minimizing total operation costs. The approach integrates key technical constraints, particularly the interdependencies between heat and power production in CHP units. Optimal energy management is evaluated across three scenarios: standalone CHP systems, CHP with RES, and a comprehensive model including battery storage (BS) systems. A model is developed to accurately represent the non-convex feasible operating regions of CHP units, highlighting the intricate interactions between electricity and heat generation. Additionally, a framework is introduced that accounts for the dual dependency of electricity and thermal output, enhancing resource allocation optimization. The study investigates the impact of RES, CHP, and BS on active and reactive power losses, operational costs, and voltage profiles. To improve financial efficiency, strategies for selecting cost-effective technologies are explored, evaluating five battery types: Lithium-Ion (Li-ion), Sodium-Nickel Chloride (Na-NiCl2), Nickel-Cadmium (NiCd), Sodium-Sulfur (NaS), and Lead-Acid (Pb-A). The analysis emphasizes the importance of diverse energy sources in mitigating voltage fluctuations and ensuring compliance with electrical standards. It is observed that the proposed method helps reduce active losses by 28.15% and reactive losses by 33.36% for a comprehensive model that includes the BS system. Additionally, operational costs decrease with the integration of RES and BS, highlighting economic benefits. Voltage profiles also improve, with BS enhancing stability during peak demand, underscoring its crucial role in future energy system designs.