Workers at Ultium Cells, the US battery joint venture between LG Energy Solution and General Motors, celebrate the start of mass production of lithium iron phosphate battery cells for energy storage system applications at the company’s Tennessee plant on Tuesday. (Ultium Cells) LG Energy Solution has started mass production of lithium iron phosphate (LFP) battery cells at its US joint venture plant with General Motors, accelerating its push into the fast-growing North American energy storage systems market.According to the joint venture Ultium Cells on Tuesday, the commercial rollout comes about four months after the company announced plans to invest roughly $70 million to convert part of its Tennessee plant’s production lines to manufacturing LFP batteries for ESS.The battery cells will be supplied to customers through Vertech, LG Energy Solution’s North American ESS system integration subsidiary. They are expected to support a wide range of applications, including grid stabilization projects, renewable ESS and power infrastructure for artificial intelligence data centers.Notably, the US-made cells qualify under the domestic manufacturing requirements of the Inflation Reduction Act that effectively blocks out Chinese supply chains, clearing out potential regulatory hurdles.Ultium Cells said the production line conversion was completed in less than five months, highlighting its ability to rapidly adjust manufacturing capacity from electric vehicle batteries to ESS in response to changing market demand. The launch of mass production has also brought back employees at the Tennessee plant who had been placed on temporary layoff in January.The Tennessee plant marks another milestone in LG Energy Solution’s plan to establish five major ESS battery manufacturing hubs across North America.The company already produces ESS batteries at its plant in Holland, Michigan, and L-H Battery Company, its Michigan-based joint venture with Honda. With its facility in Lansing, Michigan, set to begin operations later this year, LG Energy Solution expects its annual North American ESS production capacity to exceed 50 gigawatt-hours.LG Energy Solution is also expanding its North American ESS customer base. It has clinched supply agreements with customers including Tesla, Terra-Gen, Excelsior Energy Capital, EG4 and Hanwha Qcells. In May, it signed a 6-gigawatt-hours ESS battery supply deal with DTE Energy for projects such as Oracle’s AI data centers.Ultium Cells President and CEO Park In-jae said, “Leveraging LG Energy Solution’s advanced battery technology and the dedication of our Tennessee workforce, we have successfully built an ESS production system that combines speed, flexibility, safety, quality and productivity.”