ESS Tech, Inc.

ESS Tech, Inc. is a long-duration energy storage company that specializes in iron flow battery technology. The company designs and produces long-duration batteries primarily using earth-abundant materials. These batteries are designed to be cycled over 20,000 times without capacity fade, based on lab-scale results. The batteries operate using an electrolyte composed mainly of salt, iron, and water, making the products environmentally sustainable and substantially recyclable or reusable. ESS Tech's batteries offer flexibility to grid operators and provide energy assurance for commercial and industrial customers. The technology addresses energy delivery, duration, and cycle-life within a single battery platform. The company designs and builds this core technology, including battery stacks, electrolyte, and electrolyte health management solutions, into a core power train. This power train is then sold in their current product focus: the gigawatt-hour scale, fully configurable Energy Base and core power trains that can be assembled at the customer site into complete storage solutions. The company's original product offerings, the Energy Warehouse and Energy Center, are not currently for sale. ESS Tech's batteries are non-flammable and can operate in temperatures ranging from -15°C to 50°C with minimal auxiliary loads. ESS Tech, Inc. was founded in 2011 and became a publicly traded company through a business combination with ACON S2 Acquisition Corp.