Alkaline Water Electrolysis is one of the world's oldest and most proven hydrogen production technologies, operating for over a century across chemical, fertilizer, and refining industries. It produces hydrogen at around ninety-nine percent purity using potassium or sodium hydroxide as the electrolyte. A newer evolution, Anion Exchange Membrane electrolysis, removes the liquid electrolyte entirely, improving efficiency and simplifying system design. Companies including Nel Hydrogen, Siemens Energy, Thyssenkrupp Uhde, and Enapter are scaling both technologies to meet surging global green hydrogen demand.