{"id":11162,"date":"2023-05-24T10:00:00","date_gmt":"2023-05-24T14:00:00","guid":{"rendered":"https:\/\/www.plugpower.com\/?p=11162"},"modified":"2024-02-26T11:27:19","modified_gmt":"2024-02-26T16:27:19","slug":"hydrogen-electrolyzers-101-why-they-matter-for-sustainable-energy","status":"publish","type":"post","link":"https:\/\/www.plugpower.com\/hydrogen-electrolyzers-101-why-they-matter-for-sustainable-energy\/","title":{"rendered":"Hydrogen Electrolyzers 101: Why They Matter for Sustainable Energy"},"content":{"rendered":"\n

What is an electrolyzer? And what kind of role will they play in helping the world meet net-zero goals? Here is the A to Z of electrolyzers.<\/p>\n\n\n\n

\"Green<\/figure>\n\n\n\n

A. Introduction to Electrolyzers<\/strong><\/h2>\n\n\n\n

If solar power is defined by solar cells and wind production propelled by wind turbines, then the equivalent for green hydrogen production is the electrolyzer.<\/p>\n\n\n\n

Put another way, an electrolyzer serves as \u201cthe building block of green hydrogen,\u201d Plug President and CEO Andy Marsh told Bloomberg<\/a> in July 2022.<\/p>\n\n\n\n

B. Benefits of Electrolyzers<\/strong><\/h2>\n\n\n\n

Electrolyzers that use renewables to power their hydrogen production – like wind, solar, hydroelectric power, or certain biofuels – churn out emissions-free production of green hydrogen.<\/p>\n\n\n\n

Down the value chain, green hydrogen will prove increasingly crucial for the production of green ammonia and methanol, chemical compounds crucial for the future of more sustainable agricultural practices, chemical production, and seaborne shipping.<\/p>\n\n\n\n

Beyond output value, electrolyzers can also be used for longer-term energy storage, producing hydrogen that is stored in pressurized vessels for later use, with \u201cmuch higher storage capacity compared to batteries (small scale),\u201d according to<\/a> the alternative energy advocacy organization American Clean Power.<\/p>\n\n\n\n

C. Components of Electrolyzer Stacks<\/strong><\/h2>\n\n\n\n

Electrolyzers essentially function like fuel cells, but in reverse.<\/p>\n\n\n\n

At the most basic level, water is provided to the electrolyzer stack, which looks like a multi-decker sandwich. The three layers in PEM electrolyzers utilized by Plug \u2013 called a cathode, an anode and a special membrane painted with a catalyst to separate the water into hydrogen and oxygen, using electricity to power the reaction. The hydrogen is then captured and stored for a variety of end uses.<\/p>\n\n\n\n

\"PEM<\/figure>\n\n\n\n

D. Different Types of Electrolyzers<\/strong><\/h2>\n\n\n\n

There are three different water-splitting electrolyzer types: Alkaline, Solid Oxide, and Proton Exchange Membrane, the latter of which is utilized by Plug.<\/p>\n\n\n\n

Alkaline electrolyzers use water and a liquid electrolyte, generally either potassium hydroxide  or sodium hydroxide. They run at an internal temperature of just below 100\u00b0C. Solid oxide electrolyzers, sometimes also known as solid oxide electrolysis cells (SOECs), make use of a solid oxide ceramic electrolyte in producing hydrogen. Those run at internal temperatures of 500o<\/sup>C to 850o<\/sup>C.<\/p>\n\n\n\n

And PEM electrolyzers utilize a proton exchange membrane functioning as a solid polymer electrolyte. When electricity runs through the stack during the water electrolysis process, the water splits into hydrogen and oxygen. Hydrogen then passes through the membrane and ejects on the cathode side. PEM electrolyzers run at ideal temperatures of 60o<\/sup>C to 80o<\/sup>C.<\/p>\n\n\n\n

E. Electrolysis Process<\/strong><\/h2>\n\n\n\n

The water electrolysis process utilized within Plug\u2019s PEM electrolyzers is an electrochemical process that splits water into hydrogen and oxygen gases. At its simplest, the stack consists of a multi-decker sandwich of anodes and cathodes separated by proton exchange membranes coated in catalyst.<\/p>\n\n\n\n

Here\u2019s a simple explanation of how a PEM electrolyzer works:<\/p>\n\n\n\n

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  1. Water supply: the electrolyzer requires a source of water, which can be provided through a water inlet<\/li>\n\n\n\n
  2. Electrolysis process: when the power supply is turned on, an electric current flows through the electrolyte and causes a reaction at the electrodes:\n