Integrating Renewable Energy into Electrical Systems for Smart Buildings: A Pathway to Net Zero Energy Buildings

Abstract

This research aims to analyze the energy usage behavior of the Industrial Technician School Building at the College of Industrial Technology and Management, Rajamangala University of Technology Srivijaya. The objective is to develop an optimal design approach for integrating solar photovoltaic (Solar PV) systems and energy storage systems (ESS), along with improving energy efficiency through load management and power factor (PF) enhancement. The analysis revealed that the building has an average electrical load of approximately 80 kW. A Solar PV system with a capacity of 427 kW can supply around 80% of the average daily energy demand, based on average solar irradiance of 4.5 hours/day and a system performance ratio of 80%. For nighttime or non-solar hours (approximately 4 hours), an ESS with a capacity of 300–350 kWh is sufficient to meet the critical load. Additionally, the power factor was found to be below 0.5 on several days, which contributes to energy losses and increased costs. Therefore, it is recommended to install a capacitor bank or smart inverter to improve the PF to a range of 0.9–1.0. Overall, the integrated system design resulted in more than a 25% improvement in energy efficiency, with a 30–35% reduction in monthly electricity costs. Furthermore, it can reduce energy losses due to low PF by over 15–20%, and decrease dependence on grid electricity by 70–80% per day. This study demonstrates that integrating renewable energy with intelligent load management is a viable strategy to transition educational buildings toward becoming Net Zero Energy Buildings (NZEBs) in a sustainable manner.