Potential for feeder equipment upgrade deferrals in a distributed utility

摘要

This analysis is an initial assessment of the resource potential for applying distributed utility (DU) technologies to meeting load growth on feeders within substations. DU concepts allow major utility investments in transmission and distribution equipment upgrades to be deferred or avoided by applying technologies such as generator sets, fuel cells, battery storage, or demand-side management (DSM) to the building and industrial loads served by the feeder. By applying these technologies at the feeder level, the economic and operational benefits to the utility of reduced need for new generating and transmission capacity can be compounded dramatically. These additional benefits result from avoiding distribution equipment upgrades resulting from load growth and from downsizing feeder equipment during normal replacement cycles. This assessment of the resource potential of a generic DU technology uses time-series load estimates for about 3000 feeders comprising the entire load of a large utility. The analysis models DU resource purchase and operation using externally derived operating constraints designed to approximate the effect of economic constraints. This first glimpse at utility-wide application of DU technologies shows potential impacts ranging up to 10% of total distribution capacity after 10 years in high growth scenarios, and approaching 100% of new distribution capacity at lower growth rates. The analysis involves a number of simplifications for its initial phase; nevertheless, it is the first comprehensive look at DU potential for a utility system from the level of feeder loads.