Biogas, cost-effectiveness, demand response, energy management, frequency stability, microgrids, Electrical engineering. Electronics. Nuclear engineering, TK1-9971

This study develops a grid-connected solar PV–biogas microgrid for a five-story residential building in Rajshahi, Bangladesh, optimized using HOMER Pro. Among six configurations, the optimal configuration, integrating solar PV and a biogas generator, achieves a 59.4% renewable fraction, reducing CO2 emissions by 46% and lowering the cost of energy to ${\$}$ 0.0306/kWh. The system’s net present cost is ${\$}$ 46,813, with an annual operating cost of ${\$}$ 1,187. It generates 31,168 kWh/year from solar PV and 3,040 kWh/year from biogas, with grid purchases and sales of 21,951 kWh/year and 13,411 kWh/year, respectively. Predictive modeling ( $R^{2} = 1.0$ ) enhances power estimation accuracy. MATLAB-based stability analysis confirms seamless voltage and frequency integration. A demand response strategy achieves 2,730.44 kWh/year savings, reducing non-renewable reliance. The analysis results show the microgrid’s high reliability, with negligible Energy Not Supplied (ENS) is $4.31\times 10^{-14}$ kWh and an almost zero Loss of Power Supply Probability (LPSP) is $1.06\times 10^{-18}$ , indicating stable and uninterrupted power supply. Sensitivity analysis identifies solar irradiance as the dominant cost factor. The results establish a scalable, cost-effective model for residential renewable microgrid adoption globally.