ESS Inc

ESS Inc. (NYSE: GWH) is a Wilsonville, Oregon-based manufacturer of long-duration energy storage (LDES) solutions built on proprietary iron flow battery technology. Founded in 2011 by scientists and engineers with deep expertise in fuel cells, electrochemistry, and advanced materials science, ESS uses iron, salt, and water - among the most abundant and environmentally benign materials on Earth - to produce battery systems that can store energy for 4 to 22+ hours. Their core product lines, the Energy Warehouse™ and Energy Center™, serve commercial and utility-scale customers, and in 2025 the company launched its next-generation Energy Base solution, which decouples power capacity from energy capacity and enables up to 22 hours of storage at dramatically lower cost per kWh.

ESS's iron flow technology represents a compelling alternative to lithium-ion in the long-duration storage segment. Unlike lithium, iron is domestically abundant, non-toxic, and non-flammable, making ESS batteries inherently safer and less reliant on foreign supply chains. The systems are designed for 20+ year lifespans with 10,000+ operating cycles, and have earned multiple safety certifications (UL 9540A, UL 1973, UL 9540, and IEEE 693 for seismic resilience). ESS has deployed systems across the US, Europe, and Australia, and was recognized by the U.S. Department of Commerce as a leading American clean technology exporter. In 2024, ESS secured a $50M manufacturing expansion loan from the Export-Import Bank of the United States under its Make More in America Initiative, further anchoring domestic production.

ESS is strategically important to the US energy supply chain as the grid increasingly demands multi-hour and overnight storage to firm up intermittent renewable energy from wind and solar. The company's use of domestically sourced raw materials directly reduces America's dependence on lithium and critical minerals concentrated in China and other geopolitically sensitive regions. ESS has attracted high-profile partners including Honeywell, which invested in and launched a global collaboration with ESS in 2023. Most recently, ESS announced partnerships with Google and Salt River Project for the "Project New Horizon" LDES initiative, commissioned iron flow battery systems for California's Turlock Irrigation District, and is now expanding into sodium-ion technology, with a pipeline of early-stage opportunities approaching $1 billion in just seven weeks of outreach.