Design of a flywheel energy storage system (fess) with plc node-red control system for electrical energy generation during off-peak hours

Abstract

This paper presents the design, simulation, and implementation of a Flywheel Energy Storage System (FESS) integrated with a Node-RED Programmable Logic Controller (PLC) supervisory control system. The system is engineered to store electrical energy during off-peak hours and generate/discharge it during periods of high demand or grid instability. The core electromechanical design focuses on a high-speed composite rotor operating in a low-vacuum environment, coupled with a permanent magnet synchronous motor/generator (PMSM). Numerical simulations and prototype data confirm a designed storage capacity of 5.0 kWh and a maximum continuous output power of 100 kW. The system achieves a round-trip efficiency (RTE) of 87% when operating over a 15-minute discharge cycle, with rotor speeds ranging from 8,000 RPM at minimum state-of-charge (SoC) to 20,000 RPM at maximum. The bespoke Node-RED control interface, communicating via Modbus TCP/IP with the industrial PLC, enables automated scheduling for off-peak charging (simulated nightly from 00:00 to 05:00 hrs) and on-demand dispatch. Real-time monitoring of key parameters—including rotor speed (accuracy ±50 RPM), chamber pressure (maintained below 0.1 mbar), and bearing temperature—demonstrates stable operation. Economic analysis for the scaled prototype indicates a levelized cost of storage (LCOS) of $0.15/kWh over a 20-year lifespan, primarily driven by the high cycle life (>100,000 deep cycles) of the FESS. The results validate the proposed FESS-PLC-Node-RED architecture as a reliable, efficient, and programmable solution for temporal energy arbitrage and grid support, effectively shifting off-peak energy for use during peak periods.