Evaluating the rationale for the utility-accessible external disconnect switch

The utility-accessible alternating current (AC) external disconnect switch (EDS) for distributed generators, including photovoltaic (PV) systems, is a hardware feature that allows a utility's employees to manually disconnect a customer-owned generator from the electricity grid. Proponents of the EDS contend that it is necessary to keep utility line workers safe when they make repairs to the electric distribution system. Opponents assert it is a redundant feature that adds cost without providing tangible benefits. In this paper, we examine the utility-accessible EDS debate in the context of utility- interactive PV systems for residential and small commercial installations. We also evaluate the rationale for EDS requirements.