Micro-Grid of Batteray Energy Storage System (BESS) Design for Malaysia’s Net Energy Metering (NEM)

Abstract

The depletion of fossil fuels and the increasing demand for energy have led to the adoption of renewable energy sources like solar photovoltaic (PV) systems. Net energy metering (NEM) has given individuals and organizations the ability to generate electricity using PV and sell excess energy back to the grid. However, without a battery energy storage system (BESS), the excess energy can only be sold back at a lower feed-in-tariff (FiT) rate. The integration of BESSs with PV systems has become necessary to avoid potential energy savings loss. This study addresses this gap by simulating an AC-coupled BESS with a capacity of 200kWh in MATLAB. Six modes of operation are discussed in the battery management system (BMS) to verify the performance and cost-effectiveness of the BESS for AC-coupled interconnection systems. A lithium-ion battery was chosen due to its high energy density, and long cycle life. The simulation results are based on the state of charge within 20% to 80% of battery capacity and include PV generation, load consumption, battery energy, battery state of charge (SOC), and grid energy. The study also evaluates the cost-effectiveness of the integrated BESS-PV system under NEM policies in Malaysia. The results show that the BESS can effectively reduce the amount of energy purchased from the grid, maximizing cost savings up to 12% per day under NEM 3.0 policies. The study provides valuable insights and recommendations for future implementation of BESS with PV system in the storing and using renewable energy efficiency, contributing to a more sustainable energy future.