Improvement on energy consumption of a refrigerator within PV system including battery storage

Abstract

Refrigerators consume significantly high energy and the improvement on their efficiency is essential to minimize greenhouse gas emission. Understanding the power consumption patterns of refrigerators is a key element that is not thoroughly studied, especially in domestic PV system with an integrated battery-storage. Therefore, the main objective of the study is to develop strategies in decreasing the energy consumptions of systems including inverter-driven refrigerators in commercial and residential sectors. This paper compares measurements of the power consumption of two types of appliances, inverter-driven and traditional/non-inverter driven refrigerators when operating in DC and AC environment. The energy consumption was measured experimentally at four different temperatures from 10 °C to 40 °C to provide information on underlying energy changes due to changes during normal use. The work proposes an efficient configuration with DC environment appropriate for PV with battery storage applications. The overall system efficiency is adopted as a factor to evaluate the system performance for comparing two DC system topologies, DC-Load and DC-inverter-load. The comparison results of size equivalent refrigerators indicated that around 300 Wh of daily energy can be saved when just switching to the new inverter technology and smoother power pattern, especially at higher ambient temperatures. The results also found that the voltage level (310–325)VDC is the most appropriate value for the photovoltaic system integrated with battery storage of DC environment. This study provides researchers reasonable estimates on the daily energy consumption for other refrigerators at different operating conditions.

Keywords

• Compression refrigeration system
• DC microgrid
• Total power consumption
• Building energy modeling
• PV-battery systems