ESS Inc becomes ‘US’ first publicly-traded long-duration energy storage company’

October 12, 2021
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ESS Inc staff and leadership at Times Square, New York. ESS Inc later rang the opening bell as trading commenced. Image: ESS Inc via Twitter.

Shares and warrants of iron flow battery provider ESS Inc have commenced trading on the New York Stock Exchange (NYSE). 

Shareholders in special purpose acquisition company (SPAC) ACON S2 Acquisition Corp voted to approve a business combination with ESS Inc, which then went ahead and created the combined, NYSE-listed entity. 

ESS Inc is the only global manufacturer of a flow battery technology based on iron and saltwater electrolytes, packaging them into energy storage systems for commercial and industrial (C&I) and utility-scale applications. 

Holding key patents for its technologies, former CEO (now president and co-founder) Craig Evans told this site a while back, it’s not that other providers don’t want to produce batteries based on all-iron electrolytes, “it’s that they can’t”. 

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The company signalled its intent to gain its public listing in May this year and since then has struck a couple of key deals: an 8.5MWh order from Enel Green Power España which could signal the start of a wider collaboration with Enel Green Power across EU territories, and a framework agreement with SB Energy to buy up to 2GWh of the flow batteries by 2026.  

Along with Softbank’s SB Energy, other investors in the manufacturer to date have included Bill Gates’ Breakthrough Energy Ventures.

“This is an incredibly proud moment for the entire ESS team and a milestone for the industry at large. We are excited to begin our next chapter as the first publicly traded long-duration energy storage company,” CEO Eric Dresselhuys said of the listing.

“Our differentiated battery technology gives us a first mover advantage in a rapidly expanding market, while simultaneously transforming the value proposition of long-duration storage to support renewable energy generation for the electrical grid. The proceeds from this transaction will enable us to scale our operations to meet the growing global demand for a product that the world needs today to support the transition to clean, renewable energy.”

The transaction primarily comprises US$308 million pro forma net cash to the combined company, and a private investment in public equity (PIPE) included in that involved institutional investors including Breakthrough and SB Energy Global Holdings along with others including Fidelity Management and Research, Koch Industries, Tortoise Capital Advisors and BASF Venture Capital. 

As of 4pm at 11 October 2021, 3,115,177 units of ESS Inc stock was trading on the NYSE under the ticker GWH at US$10.42, having opened in the morning at US$8.60. 

ESS Inc leadership remains in place, with Dresselhuys at CEO and Craig Evans as co-founder and president, co-founder and chief technology officer Julia Song and chief financial officer Amir Moftakhar.

It’s the latest in a series of energy storage SPAC-led stock exchange listings. Eos Energy Enterprises, which makes zinc battery-based energy storage systems, might dispute ESS Inc’s description of itself as the first long-duration storage to publicly list. Eos got listed last November on NASDAQ and like ESS Inc, claims its battery technology is good for large-scale applications requiring up to 12 hours storage duration. 

Other recent energy storage and related SPAC-driven listed companies include commercial and industrial (C&I) energy storage provider Stem Inc and lithium battery recycling specialist Li-Cycle. Leading energy storage system integrator and technology provider Fluence has eschewed the SPAC route, choosing instead to float an initial public offering (IPO) in the coming months

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