TECHNO-ECONOMIC COMPARISON OF LITHIUM-ION AND VANADIUM REDOX FLOW BATTERY WITH TARGET COST DEFINITION FOR A DOMESTIC SCENARIO

This study aims to conduct a techno-economic comparison of two battery technologies suitable for storing renewable electricity: lithium-ion battery (LiB) and vanadium redox flow battery (VRFB).The analysis is conducted using a Mixed Integer Linear Program (MILP) to determine the optimal use of locally produced renewable energy, coming from either a photovoltaic solar or wind source, in order to minimize the expenses of a domestic user, for an Italian case study.The investigated batteries added to the outlined energy system are modeled considering variable efficiencies and distinct degradation characteristics.Post-optimization investment analysis incorporates realistic life expectancy and component replacement for each technology.Different sizes for the batteries are investigated in a sensitivity analysis to evaluate the impact of energy and power sizes on the Net Present Value (NPV) and the Discounted Payback Period (DPBP) of the investment upon storage deployment.Results indicate that pairing storage with photovoltaic systems proves more profitable than with wind farms, given comparable battery sizes, but storage profitability remains insufficient for both technologies.To reach profitability within 10 years from the storage installation in a domestic system producing solar energy, batteries should decrease their initial cost by at least 17-51%.In particular, the most successful VRFB, with 6 hours of discharging time, should decrease its total specific cost from about 366 €/kWh to about 241-305 €/kWh, while the most successful lithium-ion battery, with 4 hours of discharging time, should decrease its cost from about 397 €/kWh to about 196-217 €/kWh.