International Journal of Research in Advanced Electronics Engineering
2026, Vol. 7, Issue 1, Part A
Low-cost IoT-based power factor monitoring system for small-scale industries using ESP32
Author(s): Kim Sung-Ho, Park Ji-Yeon, Lee Min-Jun and Choi Hye-Won
Abstract: Poor power factor in small-scale industrial facilities results in increased electricity costs, reduced system efficiency, and potential penalties from utility providers. While large manufacturing plants commonly employ sophisticated power monitoring equipment, smaller enterprises often lack affordable solutions for continuous power factor surveillance. This research presents the development and validation of a low-cost Internet of Things based power factor monitoring system utilizing the ESP32 microcontroller platform, designed specifically for budget-constrained small-scale industries. The proposed system integrates a ZMPT101B voltage sensor and SCT-013-030 current transformer with an ESP32-WROOM-32 module to measure voltage and current waveforms, calculate power factor through zero-crossing detection, and transmit data to a cloud platform for remote monitoring. The hardware cost totals approximately 45,000 Korean Won (roughly 35 USD), representing a fraction of commercial power analyzer prices. ThingSpeak cloud platform enables real-time data visualization, historical trend analysis, and automated alert generation when power factor falls below configurable thresholds. Field validation was conducted across three small-scale manufacturing units in Incheon Industrial Complex from September to November 2024. The system demonstrated measurement accuracy of 98.5% compared to a calibrated Fluke 435-II reference instrument, with mean absolute error of 0.012 in power factor readings across six different industrial load types including induction motors, CNC machines, and welding equipment. Continuous 24-hour monitoring revealed that participating facilities operated below the 0.85 target power factor for an average of 58% of production hours, identifying substantial opportunities for power factor correction and associated cost savings. The IoT connectivity enabled remote monitoring capabilities that allowed facility managers to receive real-time SMS and email alerts during critical low power factor events. Economic analysis indicates potential monthly savings of 125,000 to 185,000 Korean Won per facility through avoided utility penalties and improved energy efficiency. The research demonstrates that affordable IoT-based monitoring can bring industrial-grade power quality awareness to small enterprises previously excluded by equipment costs.
DOI: 10.22271/27084558.2026.v7.i1a.72
Pages: 21-25 | Views: 55 | Downloads: 27
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How to cite this article:
Kim Sung-Ho, Park Ji-Yeon, Lee Min-Jun, Choi Hye-Won. Low-cost IoT-based power factor monitoring system for small-scale industries using ESP32. Int J Res Adv Electron Eng 2026;7(1):21-25. DOI: 10.22271/27084558.2026.v7.i1a.72
