Dr. K. Chandra Sekhar 03 04 Renewable energy sources such as solar photovoltaics and wind are inherently intermittent and energy storage is essential to match their fluctuating output to the load No single storage device combines high energy high power long life and low cost which motivates hybrid energy storage systems that combine complementary devices This paper evaluates the performance of a hybrid renewable energy storage system supplying a standalone microgrid from solar PV and wind in which a lithiumion battery is combined with a supercapacitor and coordinated by a frequencybased energymanagement strategy A model of the generation storage and control is developed and the system is assessed through simulation using roundtrip efficiency battery state of charge dynamic power sharing loss of power supply probability LPSP renewable fraction and levelised cost of energy LCOE as performance metrics The results show that adding a supercapacitor smooths the battery state of charge removes highpower transients from the battery and improves the roundtrip efficiency from about 88 to 92 while lowering the LCOE to about 029 kWh A storage capacity of 125150 kWh is found sufficient to meet a 1 reliability target and an optional hydrogen pathway further improves reliability at the expense of efficiency and cost The batterysupercapacitor hybrid is identified as the most favourable configuration for typical renewable microgrid operation Copyright (c) Journal of Engineering Technology and Sciences. All rights reserved 2026