The collapse marks a stark reversal for a company that was briefly valued at more than $1 billion when its shares began trading on the New York Stock Exchange in 2021. ESS had hoped its iron-based batteries would provide a cheaper, longer-duration alternative to lithium-ion systems, allowing solar and wind farms to store surplus power for periods when the sun isn't shining and the wind isn't blowing.

That promise never translated into sales. ESS had projected revenues of up to $300 million by 2023 but reported just $7.5 million in sales that year. It posted an $86 million loss in 2024 and nearly shut down in 2025 before a last-minute capital infusion kept the doors open. The company started 2025 with 240 employees, most of them based in Wilsonville; it did not disclose Friday how many remained at the time of the closure.

Bill Gates' clean power fund, Breakthrough Energy Ventures, was an early investor, but the company's stock was depressed for years and it remained more popular with day traders than with institutional Wall Street investors.

The shutdown leaves a hole in Oregon's emerging clean-technology sector and raises questions about the viability of long-duration storage startups that rely on public markets and venture capital to scale manufacturing. ESS was one of the few publicly traded companies headquartered in Wilsonville, and its closure eliminates a significant local employer.

Chapter 7 bankruptcy typically involves the sale of a company's assets to pay creditors, with any remaining funds distributed according to bankruptcy law. Employees are generally treated as unsecured creditors for unpaid wages and benefits, though federal law provides some protections for certain earned compensation.

The company did not immediately respond to questions about severance, the status of its Wilsonville facility or the timeline for liquidation.