A modular monitoring and control system for NEMA-style load center smart electrical distribution panels is built up from interconnectable modules, starting with a Base Unit for monitoring and reporting on select branch circuits, then adding a Control Module for Remotely Operated breakers or additional current monitoring or both; and/or adding a separate Expansion Module with Current Transformer expansion capabilities for adding a larger number of power monitors within the load center. The modules plug into breaker pole slots within the panel for ease of installation and are independent of the breakers. The system keeps initial smart panel costs low by placing monitoring and control functionality and required parts into add-on modules.