by Jeff St. John
May 25, 2016

We’ve been looking hard for evidence of life in the solar-plus-energy storage market, with little to show for it so far. Sure, GTM Research projects that the U.S. market for battery-backed solar will reach more than $1 billion by 2020. But at present, less than 1 percent of U.S. solar PV installations come with energy storage.

There are plenty of reasons for this. Batteries are still cost-prohibitive for most grid-tied or behind-the-meter settings and markets, whether or not they’re paired with solar. Falling battery prices and new...