The solar-plus-storage combination is super-charging the deployment of batteries across the country and IHS Markit says the U.S. will become the largest market for grid-tied energy storage this year.

According to IHS Markit, the U.S. grid-tied energy storage market is poised to nearly double this year, to 712 MW from 376 MW last year. The market research company says that will see the United States overtake South Korea, the world’s largest grid-tied energy storage market in 2017 and 2018.

And that is just the beginning. IHS expects almost 5 GW of energy storage – 90% of it lithium-ion batteries – to be deployed in the United States up to 2023.

The consultancy says a big driver in the growth of energy storage deployment over the next four years will be batteries coupled with utility scale solar, a combination it expects to account for more than 40% of battery deployments – roughly 2 GW.

That advance is being made possible by multiple factors including falling costs.

When the dramatic cost declines seen for lithium-ion batteries are factored in, the combination becomes unstoppable, according to PV magazine USA.