Planning-stage sizing of a PV – wind – battery – diesel microgrid under joint reliability and operational CO₂-intensity constraints

This study proposes a planning-stage techno-economic framework for sizing a standalone PV–wind–battery–diesel microgrid under simultaneous reliability and operational carbon-intensity constraints. Candidate system configurations defined by photovoltaic capacity, wind capacity, battery storage size, and diesel generator rating are evaluated using an hourly energy-balance simulation over a full annual cycle. Supply reliability is enforced through a loss-of-power-supply probability (LPSP) constraint of 1%, while environmental performance is controlled via a delivered-energy CO₂-intensity threshold of 0.25 kg CO₂/kWh. Renewable resource and load profiles were obtained from publicly available datasets to support transparency and reproducibility. System performance metrics included unmet load, renewable curtailment, battery utilization, diesel dispatch, fuel consumption, and levelized cost of electricity (LCOE). Results showed that feasible configurations achieved LCOE values between 0.19 – 0.31 USD/kWh and operational CO₂ intensity between 0.14 – 0.29 kg CO₂/kWh. Increasing renewable penetration and battery storage reduced diesel energy contribution by 52 – 78%. The framework provides a transparent and reproducible screening approach for identifying technically feasible and economically viable hybrid microgrid configurations prior to detailed optimization.