Design of a Microcontroller-Based Energy Monitoring System for Office Buildings at the University of Calabar

Background: Excessive and unmonitored electrical energy consumption in Nigerian university office buildings contributes to escalating electricity costs and unnecessary environmental burdens. Real-time energy monitoring enables informed energy management decisions. Aim: This project designed and implemented a microcontroller-based energy monitoring system for an office building at the University of Calabar, South South Nigeria. Methods: A ZMPT101B voltage sensor and an ACS712 current sensor were interfaced with an Arduino Mega to measure real-time voltage, current, power, and cumulative energy consumption. Readings were displayed on a 20x4 LCD and transmitted to a PC via serial communication. Calibration was performed against a certified energy meter. Results: The monitoring system measured power with a mean absolute percentage error of 2.1% compared with the reference meter. Energy consumption profiles were generated for five office rooms over a 30-day period, identifying peak consumption hours between 9:00 and 14:00. Average daily energy consumption per office was 4.2 kWh. Conclusion: The developed energy monitoring system provides actionable consumption data at low cost. Findings identified lighting and air conditioning as dominant consumption sources. Integration with an Internet of Things platform for remote monitoring is recommended. Keywords: energy monitoring, microcontroller, University of Calabar, Arduino, power consumption.