US just hit major milestone for energy storage – great news for solar too

THE UNITED States has now added the capacity to store a billion watts of power for one hour, and may double that total in 2018 alone, says a heady new forecast that highlights the rapid growth of the battery business.

The finding, by the research firm GTM Research and the industry trade group the Energy Storage Association, predicts sharp growth in an industry that was barely on the radar just a few years ago. Much of the subsequent growth has been inside homes but also at the scale of the electric grid, where batteries can help power companies decide when to deploy their growing store of electricity generated from renewable sources such as solar.

In general, the deployment of energy storage is good news for renewable energy and especially solar, because it helps stretch out the availability of this energy source, which would otherwise only be accessible during daylight hours.

The new report finds that installations of energy storage - overwhelmingly dominated by lithium ion batteries - grew 27 per cent to 431 megawatt hours in 2017. But the growth is expected to be more than double in 2018, up to 1,233 megawatt hours (or 1.233 gigawatt hours), the group predicts.

A gigawatt hour in this context refers to the ability to store 1 billion watts of energy for the period of one hour. That could be accomplished by installations that only store energy for an hour, but also by installations that store a half-billion watts but do so for two hours, or a quarter-billion watts for four hours - and so on. Batteries vary in how much power they are able to discharge at one time, and on how much energy they are able to store.

Either way, the 1 gigawatt hour figure is “a major landmark for the industry to reach,” said Ravi Manghani, GTM Research’s energy storage analyst and author of the new report.

The industry’s forwardlooking view might be a little too rosy, but storage is definitely advancing, said Eric Hittinger, an energy expert at the Rochester Institute of Technology, of the latest projection.

“It seems a little optimistic to me,” Hittinger said. “However, I think they, I would agree with them qualitatively that this is an industry that is going to keep growing, the markets are there already and are improving actually over time.”

The enthusiasm is reflected by Tesla, a major battery manufacturer that announced a home storage system, the Powerwall, in 2015. The company said in its latest earnings announcement that in 2018, “we aim to deploy at least three times the storage capacity we deployed in 2017.”

Hittinger noted that prices for storage still remain quite high, limiting uses and deployment.

“The Holy Grail is essentially to be able to have this largescale bulk energy storage that’s just moving energy, many megawatts across days or even weeks,” Hittinger said.