As the nation continues to grapple with the aftermath of numerous catastrophic natural disasters, identifying a reliable source of emergency residential power remains a concern. While diesel generators have historically filled this need, another unlikely source may prove to be more reliable.
Residential energy storage has grown mostly as a companion to renewable generation. It also offers other advantages, including reliable emergency power when normal delivery is disrupted due to hurricanes, wildfires and other extreme events.
Recent data shows that U.S. residential energy storage capacity is expanding at a rapid pace. According to the latest “U.S. Energy Storage Monitor” from the Energy Storage Association and Wood Mackenzie Power & Renewables (formerly known as GTM Research), the second quarter of 2018 was a first for the residential energy storage market. In that quarter, for the first time, the United States deployed more home energy storage than front-of-meter storage.
Overall, the nation deployed 156.5 megawatt-hours (MWh) of energy storage. That was three times the amount deployed in the second quarter of 2017. Of that growth, the residential segment led the way with a tenfold increase year-over-year.
The figures also represent an accelerating trend. The same report released for the first quarter of 2018 shows an increase of 36 MWh of residential storage. That was equal to the total amount installed in the prior three quarters combined. It also represented a ninefold increase from the first quarter of 2017, a 77 percent increase from the fourth quarter of 2017 and 90 percent of the entire volume for all of 2017.
Wood Mackenzie forecasts the United States will pass the milestone of 1 gigawatt-hours of installed residential energy storage some time in 2020. The company also predicts that, from 2017 to 2023, the industry as a whole will grow by a factor of 17 to an annual value of $4.3 billion.
Most of the growth has been driven by California and Hawaii, two states with policies favorable to residential storage.