The electricity system of the future is expected to include many local energy devices that can either generate electricity, like rooftop solar panels, or store energy, like electric cars. Such distributed energy resources could reduce power losses in the traditional central power plant paradigm and reduce purchases of backup power supplies. A potential complication to the hoped-for gains in efficiency, however, is that the owners of these resources—homeowners and small businesses—likely will form groups in order to have more leverage in negotiating deals with their local utilities. Researchers in this project will investigate the nature of such “micro grids” likely form, in terms of size and geographical proximity of the members, as well as whether such groups will improve the overall efficiency of the power system. The researchers will also study whether the efficient operation of a network with many distributed energy resources requires a communication system much more robust than what the researchers see emerging currently.