https://hydroxpand.com/en/blog/ Explainers on anion exchange membrane (AEM) water electrolysis from HydroXpand. en Sat, 29 Aug 2026 00:00:00 GMT https://hydroxpand.com/en/blog/2026-08-29-what-is-water-electrolysis/ https://hydroxpand.com/en/blog/2026-08-29-what-is-water-electrolysis/ Sat, 29 Aug 2026 00:00:00 GMT Water electrolysis is one reaction with a fixed price. Thermodynamics sets the floor for the energy, Faraday's law sets the charge, and stoichiometry sets the water. Everything a supplier can influence is the gap between those floors and the machine you buy. https://hydroxpand.com/en/blog/2026-08-29-what-is-alkaline-water-electrolysis/ https://hydroxpand.com/en/blog/2026-08-29-what-is-alkaline-water-electrolysis/ Sat, 29 Aug 2026 00:00:00 GMT Alkaline electrolysis is the only water electrolysis technology with a hundred years of industrial operation behind it, and it reached that position without a single noble metal. What separates it from the membrane technologies is not the chemistry but the separator, and almost every limit people attribute to alkaline electrolysis comes back to that one component. https://hydroxpand.com/en/blog/2026-08-29-what-is-pem-water-electrolysis/ https://hydroxpand.com/en/blog/2026-08-29-what-is-pem-water-electrolysis/ Sat, 29 Aug 2026 00:00:00 GMT PEM electrolyzers do things a liquid alkaline plant cannot: hold a large pressure difference, follow a variable power input, and deliver hydrogen that is already pure. All of it follows from one decision, a solid acidic membrane, and so does the bill that comes with it. https://hydroxpand.com/en/blog/2026-08-29-what-is-soec-electrolysis/ https://hydroxpand.com/en/blog/2026-08-29-what-is-soec-electrolysis/ Sat, 29 Aug 2026 00:00:00 GMT Solid oxide electrolysis does not beat the other technologies by being a better cell. It changes the accounting, paying for part of the reaction with heat instead of electricity. Whether that is an advantage depends entirely on where the heat comes from. https://hydroxpand.com/en/blog/2026-08-29-what-is-a-hydrogen-generator/ https://hydroxpand.com/en/blog/2026-08-29-what-is-a-hydrogen-generator/ Sat, 29 Aug 2026 00:00:00 GMT A hydrogen generator makes hydrogen where it is used, from water and electricity, instead of having it delivered. Sizing one is not a matter of picking a model. It is a matter of turning what you consume into a rate, and then checking five numbers against your site. https://hydroxpand.com/en/blog/2026-08-29-what-is-an-ionomer/ https://hydroxpand.com/en/blog/2026-08-29-what-is-an-ionomer/ Sat, 29 Aug 2026 00:00:00 GMT Two polymers do different jobs in the same cell. The membrane separates the gases. The ionomer sits inside the catalyst layer and carries ions the last few micrometres to the catalyst surface. Too little and the layer has no ion path. Too much and the gas has no way out. https://hydroxpand.com/en/blog/2026-08-22-electrolyzer-catalysts/ https://hydroxpand.com/en/blog/2026-08-22-electrolyzer-catalysts/ Sat, 22 Aug 2026 00:00:00 GMT A catalyst does not split water. The current does. What it changes is the voltage the reaction needs, and whether your electrolyte is acidic or alkaline decides which materials are available to do it. https://hydroxpand.com/en/blog/2026-08-22-electrolyzer-system-vs-stack/ https://hydroxpand.com/en/blog/2026-08-22-electrolyzer-system-vs-stack/ Sat, 22 Aug 2026 00:00:00 GMT A stack splits water. It does not make hydrogen you can use. Between the two sits the balance of plant, and that is where the numbers you actually buy are decided: energy per kilogram, purity and pressure. https://hydroxpand.com/en/blog/2026-08-16-what-is-aem-water-electrolysis/ https://hydroxpand.com/en/blog/2026-08-16-what-is-aem-water-electrolysis/ Sun, 16 Aug 2026 00:00:00 GMT Alkaline electrolysis is inexpensive but slow. PEM is fast but tied to iridium and PFAS. AEM keeps the solid membrane and moves it into an alkaline environment, and this is what that changes, what it has not solved, and where the technology stands measured. https://hydroxpand.com/en/blog/2026-08-16-choosing-alkaline-pem-aem/ https://hydroxpand.com/en/blog/2026-08-16-choosing-alkaline-pem-aem/ Sun, 16 Aug 2026 00:00:00 GMT There is no best electrolysis technology, only the one whose limits your project can live with. This is the set of questions that decides the answer, and what each of the three technologies is actually chosen for. https://hydroxpand.com/en/blog/2026-08-16-electrolyzer-efficiency-explained/ https://hydroxpand.com/en/blog/2026-08-16-electrolyzer-efficiency-explained/ Sun, 16 Aug 2026 00:00:00 GMT Two electrolyzers quoted at 75% and 64% can be the same machine. Efficiency figures move with the heating value basis, the measurement boundary, the current density and the age of the stack, and this is how to read one properly. https://hydroxpand.com/en/blog/2026-08-16-what-is-an-electrolyzer-stack/ https://hydroxpand.com/en/blog/2026-08-16-what-is-an-electrolyzer-stack/ Sun, 16 Aug 2026 00:00:00 GMT A stack is cells in series, held at the right pressure and fed the same electrolyte. Most of what separates a good stack from a bad one is not the chemistry inside the cells but the mechanical engineering between them. https://hydroxpand.com/en/blog/2026-08-16-what-is-an-mea/ https://hydroxpand.com/en/blog/2026-08-16-what-is-an-mea/ Sun, 16 Aug 2026 00:00:00 GMT The membrane electrode assembly is the layer stack where water is actually split. It sets the efficiency ceiling of everything built around it, and most of its performance is decided at the interfaces rather than by the ingredients.