Proton Exchange Membrane electrolysis is transforming global energy, holding 38.1% of the green hydrogen market in 2026. The sector, valued at $17.82 billion in 2025, is projected to reach $268.4 billion by the mid-2030s. Major companies including Nel Hydrogen, Siemens Energy, & ITM Power are scaling gigawatt manufacturing capacity. Governments across the US, EU, India, & China are backing the transition billions in policy-driven investment.