Designing and evaluating the grid-connected hybrid PV-WT-battery system from techno-economic perspectives

This study presents an integrated techno-economic-environmental assessment of a grid-connected hybrid photovoltaic-wind turbine-battery (PV-WT-battery) system for community-scale applications. A mathematical simulation framework was developed to evaluate the system under a self-supply-oriented dispatch strategy and dynamic electricity tariffs. Different capacity combinations of PV, WT, and battery storage were systematically analyzed using key indicators including self-sufficiency rate (SSR), self-consumption rate (SCR), levelized cost of energy (LCOE), and payback period (PBP). The results show that increasing renewable generation capacity generally improves SSR and reduces LCOE and PBP, but simultaneously lowers SCR due to growing surplus power export. Among the investigated configurations, standalone PV achieves the best economic performance, whereas the hybrid PV-WT-battery system provides the best overall balance between economic performance and supply reliability, with the highest SSR and the lowest grid electricity purchase under representative capacity settings. Sensitivity analysis further indicates that increasing battery capacity enhances both SSR and SCR but also raises LCOE, with PV-dominated systems showing the strongest dependence on storage. A comparative regional analysis between Karamay and Kashgar reveals that local wind and solar resource endowment strongly affects system behavior: Karamay exhibits higher SSR and lower LCOE but suffers from stronger curtailment, while Kashgar maintains higher SCR but lower SSR and weaker economic competitiveness. In addition, a preliminary life cycle assessment (LCA) of the 200 kW WT-200 kW PV-100 kWh battery configuration indicates that the manufacturing stage dominates life cycle carbon emissions, whereas end-of-life recycling can provide a substantial environmental offset; the corresponding carbon intensity is approximately 15.6 g CO2-eq/kWh. Overall, the results demonstrate that rational hybrid capacity allocation and region-specific design are essential for achieving economical, reliable, and low-carbon energy supply.