Optimisation of battery energy storage capacity for a grid-tied renewable microgrid

Abstract

There are various hurdles in using Renewable microgrids that have to be dealt with such as intermittency of output power as well as reliability of the system. Battery energy storage has been widely addressed as a solution to overcome the limitations of renewable energy resources. Besides, it effectively enhances the system performance and maximises economic profit. Therefore, optimal sizing of battery energy storage is a crucial task at the design stage to reduce operational cost and increase the system reliability. The aim of this paper is to propose a practical approach to achieve the optimal capacity of energy storage for a grid-tied renewable microgrid through peak shaving and energy saving techniques. However, if the system is designed to satisfy critical loads, the load profile has the most prominent influence on the battery sizing. Once the size of the battery energy storage is determined, two different scenarios are defined to verify the effectiveness of the proposed technique. In this paper, the renewable-microgrid system comprises wind turbine, solar panel, battery storage and a backup diesel generator in case of critical load presence. The problem is analysed throughout a year with 24 time steps for each day. The results confirm the effectiveness and functionality of the method from the cost minimisation and optimal operation perspectives.