Design and Implementation of an IoT-Based House Energy Monitoring System (HEMS) Using ESP32

Abstract

In an era of rising energy costs and environmental concerns, traditional monthly electricity bills fail to provide households with the real-time insights needed to optimize their energy usage. To address this gap, this project details the development of a House Energy Monitoring System (HEMS) designed to continuously and accurately measure domestic energy consumption. The HEMS prototype utilizes an ESP32 microcontroller equipped with Wi-Fi capabilities as its central processing unit. It integrates a ZMPT101B voltage sensor and an SCT-013-050 non-invasive AC current sensor to safely read analog electrical signals directly from the home's distribution box. The microcontroller processes these signals to calculate essential electrical parameters, including Root Mean Square Voltage (VRMS), Root Mean Square Current (IRMS), real power (Watts), and cumulative energy consumption (kWh). For user accessibility, the processed data is displayed locally on an LCD screen and transmitted wirelessly to a user's mobile phone via the Blynk application. This dual-display setup provides data logs updated every five seconds, allowing users to track immediate power dynamics and identify high-energy appliances. While prototype testing revealed minor sensor noise and inaccuracies at very low currents (0-0.9 Amps), the system successfully empowers users to adjust their daily habits and strategically utilize off-peak electric tariff blocks to save money. Ultimately, this HEMS aligns with the United Nations Sustainable Development Goals, specifically promoting affordable and clean energy (SDG 7) and responsible consumption (SDG 12). By illuminating hidden power usage, the system empowers consumers to reduce their carbon footprints, lower electricity bills, and actively contribute to a more sustainable energy future.