Optimal energy management in multi energy microgrid with combined heat and power system and demand side response integration

Renewable energy sources are gaining prominence due to their sustainability, low environmental footprint, and potential to reduce dependence on fossil fuels. However, their intermittent and unpredictable nature presents significant challenges for reliable energy supply. A promising solution lies in integrating multiple energy carriers, such as electricity and gas, to enhance system resilience, efficiency, and sustainability. This study presents a Multi-Energy Microgrid (MEMG) architecture featuring a DC electricity bus and a heat bus. The DC bus integrates photovoltaic (PV) panels, batteries, and a Combined Heat and Power (CHP) unit, while the heat bus connects to the gas supply network through boilers, the CHP system, and heat storage. To assess the role of CHP in system performance, three scenarios are analyzed: ‘No CHP’, ‘CHP Only’, and ‘Combined CHP and direct gas use’. Additionally, two types of demand response programs (DRPs)—incentive-based and price-based—are implemented to enhance operational efficiency and flexibility. The problem is formulated as a Mixed-Integer programming (MIP) model to meet electricity and heat demands while minimizing economic costs, emission costs, and operational expenses. To identify the most efficient solver, CPLEX, GUROBI, and Coin Branch and Cut (CBC) are tested and evaluated based on their performance. The evaluation is conducted through a case study on Belle Île en Mer (47°19’N, −3°10’W), an island in the Pays de la Loire region of France. Results indicate that the ‘Only CHP’ scenario achieves a 21% reduction in electricity costs, a 6.1% decrease in emissions costs, and a 6% overall cost reduction, despite a 35% increase in gas costs compared to the ‘No CHP’ scenario. Additionally, demand response programs effectively shift peak loads, leading to a 14% reduction in electricity costs and a 2% decrease in both gas and total costs. Although all three solvers produce similar results, GUROBI is preferred for large-scale problems with limited computational resources because it has lower computational costs. These findings highlight the potential of combining CHP systems with demand response strategies to enhance the efficiency, sustainability, and cost-effectiveness of multi-energy microgrids.