Inlyte Energy has announced a major performance milestone for its innovative iron–sodium battery technology, achieving over 80% round-trip efficiency in third-party cycle testing, including auxiliaries – which the company describes as a “significant breakthrough for long-duration energy storage.”
Southern Company research and development is expected to deploy the first integrated system in Q4 2025, seen as a critical step towards broader commercial adoption. This will be the first utility demo of the technology, with a Southern Company team preparing to operate an Inlyte iron-sodium battery installation located near Birmingham, Ala. Evaluation will last for at least one year and will be a critical phase of product validation. Results will be shared across a broad network of utilities, in collaboration with EPRI.
The third-party cycle testing results were independently validated by HORIBA MIRA. The performance milestone “positions Inlyte’s battery as a highly efficient, domestically sourced alternative to lithium-ion systems for stationary energy storage”, the company says.
The tests, conducted at HORIBA MIRA’s UK facilities, evaluated performance under realistic cycling and abuse scenarios. Results confirmed the battery’s “exceptional performance, safety, durability, and simplicity,” according to Inlyte Eenrgy. The results build upon Inlyte’s iron–sodium cell-level performance findings, which demonstrated stable performance of 90% efficiency and no capacity loss after more than 700 cycles. The new battery-level results demonstrate realised performance from the integration of 100 iron–sodium cells and associated auxiliary control systems.
In support of scaling US manufacturing, Inlyte recently announced a strategic partnership with HORIEN Salt Battery Solutions, the world’s largest producer of sodium metal chloride batteries. This collaboration accelerates domestic production, with commercial deliveries targeted for 2026.
Inlyte Energy delivers breakthrough iron-sodium battery technology enabling safe, sustainable, and domestically produced long-duration energy storage. “With simple ingredients — iron and salt — and innovative design,” Inlyte says it is “reshaping energy storage.”
