ORIGINAL REPORTING: How To Get The Big Benefits Of Grid-Integrated Water Heaters
Utilities in hot water: Realizing the benefits of grid-integrated water heaters; Water heaters offer storage capabilities at a fraction of the cost of batteries. The challenge is getting everyone a piece of the returns.
Herman K. Trabish, June 20, 2017 (Utility Dive)
Editor’s note: Attention to this and other low-hanging load shifting opportunities is growing as utilities and system operators look for ways to flatten peak demand and the costs of its spiking.
A wave of interest is building in grid-integrated water heating (GIWH) as a path to utility system flexibility at a fraction of the cost of battery energy storage. At last count, 53.6 million of the 118.2 million U.S. water heaters were electric. Each could act as a battery for load shifting, peak shaving, or to integrate renewables, according to a Regulatory Assistance Project (RAP) paper. Hot water is used largely by residential utility customers in morning and evening hours, wrote RAP Sr. Advisor Jim Lazar. But it can be heated when demand on the system is low and the stored hot water could then be used during the morning and evening without increasing system burden, Lazar wrote. To optimize the use of variable renewables, it could be heated at night to take advantage of high wind production and at midday to take advantage of abundant solar production.
Effective utility control of residential water heating could integrate as much as 100,000 MW of additional U.S. wind and solar energy, Lazar wrote.Transforming the U.S. electric water heater fleet to 100% GIWH represents a $3.6 billion per year market, according to think tank Rocky Mountain Institute (RMI). Utilities, GIWH manufacturers, installers, solar companies, aggregators, and customers themselves would all be able to benefit from the opportunity. Utilities across the country are testing hot water-as-storage. There are GIWH pilots at Portland General Electric, Arizona Public Service, and Green Mountain Power in Vermont. System operator PJM has introduced GIWH for frequency regulation and the California Energy Commission is discussing GIWH, according to Brattle Principal Ryan Hledik, co-author of a recent paper describing the GIWH opportunity… click here for more