A Sandia National Laboratories report details a procedure to quickly determine whether utilities need an additional unintentional islanding study when evaluating the proposed interconnection of new distributed generation (DG), which includes photovoltaic (PV) systems.

Islanding occurs when the DG continues to energize a load well after it is disconnected from the utility source, and when established accidentally, islanding can adversely affect personnel safety and equipment integrity. Following Sandia's procedure can reduce the planning time — and cost — of interconnecting PV by identifying situations in which the risk of unintentional islanding is extremely low.