How Water Heaters Have Evolved into Grid-Scale Energy-Storage Devices (2014)

Grid-interactive water heaters (GIWHs) add bidirectional control to electric resistance water heaters, allowing a utility or third-party aggregator to rapidly toggle them off and on. By adding bidirectional control to electric resistance water heaters, GIWHs enable a utility or third-party aggregator to quickly and repeatedly turn the devices off and on. For PJM, a single water heater providing overnight (eight hours per day) frequency regulation can generate roughly $140 per year in revenue.1 Vendors claim that the use of GIWHs in the PJM territory can result in a negative annual energy cost to the customer; that is, customers could potentially earn money by providing this service, according to the 2012 Steffes Corp. white paper Grid-Interactive Electric Thermal Storage (GETS) Water Heating (PDF).

Source: www.esource.com