Stem, Inc.
Increasing the demand reduction effectiveness of an energy storage system

Abstract:

In various embodiments, a hedge mode plugin increases the ability of an energy storage system to reduce the demand charges associated with purchasing electricity from a utility. A utility measurement interval (UMI) is divided into a pre-discharge phase and a subsequent compensatory charge phase. During the pre-discharge phase, the hedge mode plugin causes an energy storage device to discharge. At the beginning of the compensatory charge phase, the hedge mode plugin computes time-indexed charge values based on the total amount of energy that the energy storage device discharged during the pre-discharge phase. The hedge mode plugin then causes the energy storage device to charge based on at least one of the charge values. By systematically pre-discharging and re-charging the energy device, the hedge mode plugin optimizes the demand reduction effectiveness of the energy storage system during each UMI while stabilizing the state-of-charge of the energy storage device across multiple UMIs.