A major factor in the enablement of sustainable renewable energy is ensuring utilities are prepared to safely and reliably operate a grid of the future. Bi-directional power flow coupled with uncontrollable DERs requires that utility system operators and planners redesign their operation and load planning processes. Southern California Edison partnered with a third-party company to enhance and demonstrate a software application with the ability to visualize disaggregated masked load, PV generation, and flexible DERs within segmented sections of a distribution circuit. SCE successfully created higher-fidelity power system models for a 66/12kV substation and its associated feeders with 12,012 customers using customer meter and estimated solar from a 3 rd party advanced algorithm. PV penetration for this substation varies from 0.66-65%, where PV penetration is defined as the ratio of total peak solar power to peak load apparent power. The application leverages disparate data to provide planners and system operators a more granular estimate and new views of what is happening on the circuit beyond the substation feeder-head. This paper describes the methodology, data sources, validation approach, integration and visualization results and lessons learned from SCE's perspective.