Abstract
Background:
Rising electricity costs and carbon emissions in educational institutions demand urgent action through innovative energy management strategies. Inefficient operation of indoor appliances and outdoor security lighting contributes significantly to energy wastage and greenhouse gas emissions.

Aim:
This study aims to design and deploy a low-cost, automated energy management system to minimize energy wastage while improving sustainability in a university campus setting.

Methods:
The proposed system integrates a smart energy-saving device (SESD) for real-time monitoring and automated control of electrical loads, alongside a light-dependent resistor-based module for autonomous security lighting regulation. The SESD consists of three core units: sensing, control, and actuation. Baseline data on voltage, current, power factor, and idle time were collected using a Fluke 432-II Power Quality and Energy Analyzer over a 12-month period covering both dry and rainy seasons. Fifty appliances across administrative offices, classrooms, and laboratories were grouped into experimental and control sets for comparative evaluation.

Results:
The system achieved a 40% reduction in energy consumption, equivalent to 1,080 kWh saved per month, resulting in ₦243,000 (USD 200) in monthly cost savings and an annual greenhouse gas reduction of 8.88 tons of Carbon Dioxide. It demonstrated rapid response, robust switching reliability, and broader load coverage compared to similar works.

Conclusion:
The study highlights the potential of leveraging locally available components to achieve scalable, sustainable energy management in resource-constrained settings. This work provides a replicable framework for advancing Sustainable Development Goals 7 and 13, while laying the foundation for future Internet of Things-enabled analytics and remote monitoring to further enhance system intelligence and operational efficiency.

Key words: Smart energy management; Load automation; LDRbased control system; Campus energy efficiency; Sustainable electricity use; Carbon emission reduction.