Flow batteries are gaining traction as a key solution for long-duration energy storage, offering scalable capacity and cost-effectiveness for grid and industrial applications. Unlike lithium-ion batteries, flow batteries decouple power and energy, making them ideal for storing energy for hours or even days. Despite past challenges like high upfront costs and limited scale, advancements in technology, policy support, and net-zero goals are driving adoption. With the global long-duration storage market projected to grow at 14% CAGR, flow batteries are poised to play a critical role in the energy transition, enabling renewable integration and grid reliability. Companies like Vflowtech and ESS Inc. are leading the charge in commercializing this transformative technology.