Techno-Economic Optimization of a Hybrid PV–Wind–Battery–Pumped Storage System for Reliable Renewable Energy Supply

Abstract

Hybrid renewable energy systems (HRESs) have emerged as a promising solution for improving the sustainability and energy independence of critical infrastructure with continuous electricity demand. This study presents a techno-economic optimization framework for a hybrid photovoltaic (PV), wind turbine (WT), battery energy storage system (BESS), and pumped storage hydropower (PSH) configuration designed to supply a wastewater treatment plant (WWTP). The optimization simultaneously minimizes the levelized cost of energy (LCOE) and renewable energy surplus while satisfying a predefined Maximum Allowed Deficiency (MaxDef) reliability constraint. The framework is validated using two years (17,554 hourly records) of measured meteorological and operational data collected from the Ariel University wastewater treatment plant. The results demonstrate that the coordinated operation of BESS and PSH significantly improves renewable energy utilization and system reliability while reducing excess energy generation. For the investigated case study and the adopted technical and economic assumptions, an energy storage of approximately 25 kWh provides the most favorable techno-economic balance between investment cost, renewable energy utilization, and reliability. However, the optimal battery capacity is site-specific and may vary depending on local renewable resources, load characteristics, economic conditions, and reliability requirements. The proposed optimization framework provides a practical methodology that can be adapted to the design of reliable hybrid renewable energy systems for wastewater treatment plants and other critical infrastructure by incorporating site-specific operational and environmental data.