Italian company Green Energy Storage (GES) has developed a manganese-hydrogen flow battery for long-duration energy storage, targeting industrial-scale applications and large renewable energy plants. The battery boasts an efficiency exceeding 75%, a service life of over 10,000 cycles, and a low levelized cost of storage (LCOS). The cost is competitive at €0.02 per kWh per cycle compared to lithium batteries. The battery is expected to be commercially available in 2027 and is based on a flow architecture that decouples energy and power for independent sizing. Manganese was chosen for its abundance, established production chain, cost-effectiveness, and low environmental impact.