PEM electrolysis produces hydrogen with 99.999% purity & 75-80% efficiency, making it ideal for fuel cell vehicles & stationary power. However, platinum catalyst costs & membrane degradation limit widespread adoption. Over thirty companies, including Siemens Energy, Cummins, & Plug Power, are developing solutions to these challenges. The competitive ecosystem positions PEM technology for the cost reductions that could enable hydrogen to become a cornerstone of global decarbonization.