From conventional campus grid to optimized HRES microgrid: a grid-constrained techno-economic and environmental assessment of renewable energy integration at Shivaji University, India

Higher-education campuses are well suited to staged decarbonization because they combine concentrated electrical demand, substantial rooftop area, diverse load flexibility, and long-term institutional ownership of energy assets. This study develops a Campus Microgrid Renewable Integration and Energy-Saving Assessment Framework (CMR-ESAF) for planning the transition of Shivaji University, India, from grid-dependent operation to an optimized hybrid renewable energy system (HRES) microgrid. Unlike a greenfield sizing study, the framework explicitly separates three transition states: S0, a grid-only reference; S1, the existing campus with 930 kW of rooftop photovoltaic (PV) capacity; and S2, an optimized HRES incorporating PV expansion, supplementary wind generation, battery energy storage (BESS), demand-side management (DSM), and energy-management-system (EMS) dispatch under grid and campus-network constraints. The S2 planning problem is solved using an adapted NSGA-III many-objective framework with normalized constraint handling, dynamic feasibility relaxation, reference-vector association, dual archives, and fuzzy best-compromise selection. Under the stated annual hourly simulation assumptions, S0 requires 3650 MWh/yr of grid electricity, emits 2993 tCO ₂ 2 /yr, and reaches a maximum demand of 1080 kVA. S1 lowers grid import to 2430 MWh/yr, corresponding to a 33.4% reduction in grid dependency and 1000.4 tCO ₂ 2 /yr of avoided emissions. The selected S2 configuration comprises 1580 kW total PV, 150 kW wind DG, a 500 kW/1500 kWh BESS, and 130 kW of DSM participation. It reduces grid import to 1175 MWh/yr and maximum demand to 695 kVA, yielding a 67.8% grid-dependency reduction, 35.6% peak-demand mitigation, 72.3% renewable fraction, and 65.8% renewable self-sufficiency. The modeled annual utility cost decreases from INR 413.6 to 145.7 lakh/yr; the corresponding planning estimate gives a levelized campus electricity cost (LCEC) of INR 4.85/kWh and a simple payback period of 6.4 years. The principal contribution is a replicable transition framework that distinguishes the value already delivered by installed PV from the incremental benefit of coordinated HRES, storage, DSM, and EMS investment.