Achieving Nearly Zero-Energy Buildings through Renewable Energy Production-Storage Optimization

This research focuses on optimizing renewable energy systems to achieve Nearly Zero-Energy Building (nZEB) Level 1 status, defined as reducing energy consumption by 87.5% to 100%. The major objectives are to explore the impact factors in the optimization of energy storage systems (ESSs), solar PV and ESS capacities, as well as energy consumption patterns. This study is based on monitoring data from an office building in Thailand with a 120 kW peak load and a 40 kW average load, equipped with a 160 kW photovoltaic (PV) system and 45 kWh from ESS. This study is based on comparing a simulation of a renewable energy system, particularly from unutilized solar energy, with building load demand to optimize the best system suitability for achieving nZEB Level 1 status. The results indicate that a 200 kW PV system combined with a 275 kWh ESS and a 250 kW PV system with an ESS capacity of 175 kWh can adequately supply the required clean energy demand. These findings provide insights on optimizing factors of renewable energy systems for buildings aiming to achieve sustainability targets. This work has summarized a framework including optimization impact factors with financial aspects which can be applied to similar cases. In addition, an analysis of working-day load profiles and appliance usage patterns has been performed to provide broader consumption insights. This approach identifies trends in HVAC, lighting, and electronics consumption, enabling the optimization scheme to be adapted to buildings with varying load patterns. Additionally, this study examines the effects of building operation hours on energy consumption. By adjusting operational schedules based on these insights, different renewable energy system capacities can be re-estimated to ensure achievement of the desired nZEB Level.