The electric grid as it stands today was designed for an exclusively one-way powerflow from bulk generation facilities, encompassing plants from base load support to peaker plants, to end-users. In this model, instantaneous demand changes were accommodated through small, temporary frequency adjustments, quickly reversed through appropriate management of bulk generation output. Distributed Energy Resources (DER) present a substantial challenge to the traditional model. Not only can powerflows reverse during peak for several hours each day, the output of these new sources can also change much more quickly, potentially leading to much more dramatic demand swings for bulk generation than the current system can accommodate. This presentation will present a framework for analyzing new requirements for the grid during the phases of the DER roll out and discuss how systems and capabilities have to change to ensure safe and reliable power delivery as the grid undergoes its most fundamental technical and business change since its creation.