Regularly calibrating an energy monitoring system ensures accuracy

Abstract

Energy monitoring systems are being reported on more and more as consumers wish to determine the amount of energy produced and used by various renewable energy systems. Added to this is improving the overall systems’ efficiency and identifying any potential concerns. The purpose of the paper is to show the importance of correctly calibrating such energy monitoring systems on a regular basis, in order to validate any future measurements as being reliable. In this study, three 10 W PV modules are used with their own respective LED loads to extract the maximum possible amount of electrical energy during the day. No storage systems are used due to their limited life-cycle and variability. An Arduino microcontroller is used as the data logging interface between the PV systems and a PC running Lab VIEW software, which acts as the visual interface and recording system. Calibration is done in Lab VIEW to account for system losses. Results indicate that three identical PV systems can be calibrated to produce the same results, with variability of less than 1%. Higher variabilities point to inconsistencies in the PV modules, even if they originate from the same manufacturer. A key recommendation is to perform an annual calibration of the monitoring system, which primarily accounts for PV module degradation.