Techno-Economic and Reliability Assessment of Grid-Connected PV/Wind/Battery Hybrid Configurations for a Domestic District Under Unreliable Grid Conditions

Grid unreliability can compromise electricity supply in developing regions, yet comparative evidence on residential-district hybrid systems under consistent outage assumptions remains limited. This study compares four grid-connected architectures for a residential district in Egypt: wind/battery/grid, PV/wind/battery/grid, PV/battery/grid, and PV/wind/grid, using a simulation–optimization framework with net present cost (NPC) as the sole optimization objective. Supply adequacy, renewable fraction, grid interaction, and grid-related operational CO2 emissions were then assessed. Under baseline conditions, PV/wind/battery/grid was the minimum-NPC hybrid configuration, with an NPC of USD 481,851, LCOE of USD 0.0711/kWh, renewable fraction of 73.8%, unserved energy of 0.306 MWh/yr, and operational CO2 emissions of 139,533 kg/yr. Relative to grid-only supply, it reduced unserved energy by 98.5% and emissions by 65.0%, although grid-only had the lower NPC of USD 369,414. To distinguish fixed-design deterioration from adaptive redesign, baseline-optimal capacities were evaluated unchanged under a common severe grid-availability profile and compared with re-optimized counterparts. For the three battery-containing architectures with complete adaptive results, re-optimization reduced unserved energy by 73.2–97.2%, while resizing differed markedly. Among these architectures, wind/battery/grid had the lowest severe-condition NPC, only 0.63% below PV/wind/battery/grid. Deterministic ±10% sensitivity analysis retained PV/wind/battery/grid as the minimum-NPC architecture. Overall, baseline cost optimality, fixed-design transferability, and adaptation requirements are distinct, architecture-dependent planning considerations.