A power distribution control system for controlling a plurality of power assets connected to a power grid is provided. The system includes a server which can identify a set of power assets selected from sources, loads, and stores that are to form a string and provide to the string instructions for response to a change in the power grid. The system further includes a router for each of the power assets in the string, for receiving instructions from the server and for controlling the respective power asset. The power assets in the string are selected by the server to have different response times and/or response profiles, such that the string of assets present a collective response to the change, the collective response being defined by the server.