What are Electrolysers?

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What are Electrolysers? Blog Image


Investing in a homegrown electrolyser manufacturing infrastructure is anticipated to drive down the price of green hydrogen and enhance India’s competitive edge.

About Electrolysers

  • It is an apparatus that produces hydrogen through a chemical process (electrolysis) capable of splitting water molecules into hydrogen and oxygen molecules by using electricity.


  • An electrolyser consists of a conductive electrode stack separated by a membrane to which a high voltage and current is applied.
  • This causes an electric current in the water which causes it to break down into its components: hydrogen and oxygen.
  • The oxygen generated in parallel is released into the atmosphere or can be stored for later use as a medical or industrial gas in some cases.
  • The hydrogen is stored as a compressed gas or liquefied for use in industry or in hydrogen fuel cells, which can power transport vehicles such as trains, ships and even aircraft.

Types of Electrolysers

  • Alkaline electrolysers: Alkaline electrolysis is a mature and commercially available technology used primarily by the fertiliser and chlorine industries.
  • It presently accounts for almost two-thirds of the global electrolyser capacity.
  • It uses thick membranes and nickel-based electrodes.
  • Proton exchange membrane (PEM) electrolysers: It operates at high pressure, due to the use of thin perfluorosulfonic acid (PFSA) membranes.
  • However, the PFSA acidic environment makes it necessary to use gold and titanium plated electrodes and metals such as platinum, iridium, and ruthenium as catalysts.
  • They are the most popular because they produce high-purity hydrogen and are easy to cool. 
  • Solid oxide electrolysis cell (SOEC) electrolysers : They utilise heat to make hydrogen from steam and are best placed where there is a heat source available (nuclear or industrial facilities).
  • They operate at high temperatures (500 – 850degrees). 
  • Anion exchange membrane (AEM) electrolysers: They operate at significantly lower temperatures of 50 – 60 degrees.
  • They combine the less harsh conditions of alkaline electrolysers with the simplicity and high efficiency of PEM electrolysers.

Q1: What is hydrogen?

It is a clean alternative to methane, also known as natural gas. It's the most abundant chemical element, estimated to contribute 75% of the mass of the universe.

Source:Domestic manufacturing of electrolysers can be game changer for industrial emissions