When sourcing energy monitors, prioritize Measurement Accuracy, typically requiring Class 0.5s or Class 1.0 according to IEC 62053 standards. Ensure the device supports Multi-channel Monitoring if you need to track individual circuits. Key parameters must include Voltage, Current, Active/Reactive Power, Power Factor, and Harmonic Distortion (THD). For hardware, verify if the unit uses Split-core Current Transformers (CTs), which allow for installation without powering down the system, significantly reducing downtime.