Demand Charge Management: Prototype Design and Testing

This paper presents the design, implementation, and validation of a smart, low-cost Energy Management System (EMS) and Demand Charge Management (DCM) prototype, developed as part of an undergraduate senior design project. The system serves as both a practical solution for reducing electricity costs and a pedagogical tool for teaching real-time energy control concepts in power and embedded systems courses. Unlike conventional EMS/DCM solutions that rely on high-cost commercial hardware or purely theoretical models, the proposed system integrates grid power, lithium-iron phosphate (LiFePO4) battery storage, and real-time control into a unified, scalable platform constructed at a fraction of the cost, approximately $1,800 compared to over $16,000 for leading commercial options. The controller dynamically optimizes energy usage by switching between grid and battery sources based on real-time measurements of electricity prices, load power, and battery state of charge (SoC). This enables peak shaving, energy arbitrage, and backup power functionality, thereby enhancing cost efficiency and grid resilience for both residential and small commercial users. The architecture features a modular three-layer design comprising a sensing layer for electrical data acquisition, a control layer executing Python-based logic on a Raspberry Pi, and an actuator layer for seamless energy switching. Data is communicated via MQTT and visualized through the Blynk IoT platform, providing an intuitive and remotely accessible user interface. The prototype's effectiveness was validated through real-world testing, confirming its capability to reduce demand charges and ensure reliable energy delivery under varying operational conditions. Its affordability, open-source control logic, and educational versatility make it an ideal candidate for both deployment and instructional use.