ESS Inc. says it will use a just-closed $13 million Series B financing round to boost production capacity at its plant in Wilsonville, where the company makes an unconventional battery that can provide long duration energy storage.
Lithium-ion batteries are the flavor of the day in energy storage, leaving alternative technologies fighting to pry their way into the burgeoning market. But ESS CEO Craig Evans said the fresh investment demonstrates growing confidence in flow batteries, the type made by ESS.
“What we’ve needed to do with this technology is prove bankability,” Evans said Tuesday after the company announced the new funding round.
ESS has been doing that, Evans said, with a growing roster of deployments, including at a UC San Diego microgrid, a wind farm in Texas and a U.S. Army Corps of Engineers microgrid in Missouri.
Flow batteries use separate tanks of chemical solutions that are pumped into a chamber where they react through a membrane to produce electrical charge. ESS uses a non-toxic electrolyte made up of iron, salt and water instead of the commonly seen vanadium or zinc.
The battery systems can be scaled to meet small or large needs by varying the size of the tanks, and can provide three to eight hours of power vs. around half that for lithium ion. ESS packages its latest system in a 40-foot shipping container.
Evans said ESS has deployed about 1 megawatt-hour of capacity — an amount of energy equal to about what a typical home uses in a month. The company expects to deliver about 2 megawatt-hours of additional product in the first half of next year.
But this big financing round will allow it to invest in automation tools to ramp up capacity, Evans said — to 300 megawatt-hours by summer 2018 and eventually to 900 megawatt-hours, all at a 100,000-square-foot facility it recently moved into in Wilsonville.
“I don’t think we’ll have that (capacity) need in 2018,” Evans said. “But this funding allows us to get the line up, learn how to run the line and be ready for demand in 2019 and 2020.”
Energy storage can help integrate variable renewable energy sources, like solar and wind, which have been falling in cost. Evans see that feeding growth.
ESS was founded in 2011 by Evans and CTO Julia Song, who had both been with ClearEdge Power, a now defunct local fuel-cell maker. ESS landed a five-year, $2.8 million ARPA-E grant in 2012 that grew to $5 million, and picked up $3.2 million in a Series A funding round led by Pangaea Ventures.
Oregon investments in the company include $450,000 from ONAMI, $200,000 from Oregon BEST, and $150,000 from Portland Seed Fund.
Pangea returned in the Series B round, joined by several new investors, led by BASF and including Cycle Capital Management, Presidio Partners Investment Management and InfraPartners Management.