Techno-economic comparison of optimal design of renewable-battery storage and renewable micro pumped hydro storage power supply systems: A case study in Sweden

Abstract

In this study, two types of energy storages are integrated,—namely, micro pumped hydro storage (micro-PHS), and battery storage—into small-scale renewable energy systems for assessing efficiency, cost, maturity, and storage duration.Optimal design of standalone renewable-micro PHS and -battery storage systems for a remote area in Sweden is conducted to find the most suitable solution by considering techno-economic performance indicators such as investment cost, life cycle cost, levelized cost of energy, loss of power supply probability, monthly and annual oversupply, and annual ratio of renewable power to supply power. Number of photovoltaic (PV) modules, number of wind turbines (for renewable energy section), installation height of the upper reservoir, volume of reservoir, pipes diameter, depth to diameter ratio of reservoir, turbine capacity, pump capacity (for PHS section), and battery capacity (for battery storage section) constitute the set of design variables and modified non-dominated sorting Genetic Algorithm is employed as the optimization algorithm. The results show that, for the optimal design with the full satisfaction of power demand, the hybrid PV-wind-battery storage system is the best option in terms of economic benefits and reliability, leading to 18.61% lower life cycle cost and 6.12% lower oversupply, compared to the hybrid PV-wind-micro PHS system. However, the design of both hybrid PV-battery storage and PV-micro PHS systems could be considered fully satisfactory designs led to much higher annual oversupply and much higher life cycle cost in comparison with the PV-Wind-battery storage system.