A PeakPower Energy Management and Control System having one or more roll-lock snap-on current transformer power monitoring devices, each to avoid interrupting power when installing current and/or power monitors. Each roll-lock snap-on current transformer power monitoring device may be snapped onto existing power wires inside a power panel or near equipment being monitored without disconnecting any wires or turning off power. Each roll-lock snap-on current transformer power monitoring device may be utilized in standalone mode as well as within a PeakPower Energy Management and Control System in accordance with disclosed embodiments. Each roll-lock snap-on current transformer power monitoring device may communicate via the power lines (Power Line Controller) or communicate via wireless using an integrated microprocessor based RF transceiver.