ESS Tech Inc manufactures Energy Warehouse, an iron flow battery that delivers up to 8 hours of energy with a 20+ year operating life and the lowest levelized cost of storage per kWh. The battery is composed of earth-abundant iron, salt, and water for its electrolyte, making it a safe and long-lasting solution. ESS was founded in 2011 by a team with deep experience in renewable energy and began shipping turn-key battery solutions in 2016. BASF, the world's leading chemical company, became a significant investor in ESS in 2017.