Integrating heterogeneous distributed energy resources to manage intermittent power at low cost

A power distribution feeder where a heterogeneous set of distributed energy resources is deployed is examined by simulation. The resources include PV, battery storage, natural gas genset and fuel cells, and active thermal storage for commercial buildings. The resource scenario considered is one that may exist in a not too distant future, and is based on an existing demonstration system in Albuquerque, NM (USA). The operation of individual DERs, and its effects on the global power flow on the feeder, are considered. Two cases of interaction between different resources are examined. One interaction involves a genset used to partially offset the duty cycle of a smoothing battery connected to a large PV system. The other example involves the coordination of twenty thermal storage devices, each associated with a commercial building. The storage devices are intended to provide maximum benefit to the building, but it is shown that this can have a deleterious effect on the overall system, unless the action of the individual storage devices is coordinated - in which case there is overall benefit to the system. The main finding is that it is possible to achieve synergy between DERs on a system, however this required a unified strategy to coordinate the action of all devices in a decentralized way.