Among the most widely used technologies for green hydrogen production are Proton Exchange Membrane (PEM) electrolysers. These systems provide efficiency, operational flexibility and the ability to adapt to renewable energy fluctuations.
Let’s find out how PEM electrolysers work and what the advantages and limitations of this technology are.
How do PEM electrolysers work?
PEM electrolysers use a proton exchange polymer membrane to dissociate water into its basic elements, oxygen and hydrogen, by applying an electric current.
The system consists of an electrolytic cell with two electrodes: an anode and a cathode, separated by the membrane. At the anode level, water is decomposed into molecular oxygen and hydrogen ions (protons), which cross the membrane and reach the cathode, where they recombine to generate molecular hydrogen.
This technology is characterised by its ability to respond extremely quickly to load variations, making it particularly suitable for integration with renewable energy sources such as wind and photovoltaics. In addition, the hydrogen produced by PEM electrolysers reaches very high purity levels, a fundamental requirement for high value-added industrial applications and the hydrogen mobility sector.
Want to learn more about the process and how electrolysis works?
Read our article: Electrolysis: the technology that turns electricity into hydrogen
The advantages of electrolysis with PEM technology
Electrolysis based on PEM technology has a number of advantages that make it the most widely used solution for producing green hydrogen today:
- High conversion efficiency: PEM electrolysers ensure high energy conversion efficiency, minimising specific energy consumption per unit of hydrogen produced.
- Modularity and scalability: The modular design of PEM electrolysers allows for great scalability, facilitating the configuration of systems of varying sizes according to actual operational needs.
- Dynamic operation: The ability to start up and shut down quickly makes this technology particularly suitable for use with renewable sources, whose intermittent variations require systems capable of responding immediately.
- Hydrogen purity: Hydrogen obtained through PEM electrolysers is extremely pure, a quality that is essential for applications requiring very high quality standards, such as fine chemicals and mobility.
The critical issues and limitations of PEM
Despite the significant advantages, the large-scale adoption of PEM technology also presents some critical issues that will have to be resolved to make these systems more competitive in the market:
- High material costs: PEM electrolysers require the use of rare and expensive materials, such as platinum and iridium for the catalysts. This has a significant impact on production costs, reducing the competitiveness of this technology.
- Limited lifetime and maintenance: key components, such as the polymer membrane and catalysts, are subject to degradation over time. This leads to a reduction in the overall operating life of the system and an increase in maintenance and replacement costs.
- Sensitivity to water impurities: PEM electrolysers require high-purity water to avoid contamination of the catalysts. This implies additional costs for water purification and treatment systems.
Other types of electrolysers on the market
In addition to PEM electrolysers, there are other technologies for producing hydrogen by electrolysis, each with specific characteristics:
- Alkaline electrolysers (AWE)
- Anion exchange membrane electrolysers (AEM)
- Solid oxide electrolysers
In alkaline electrolysis, hydroxide ions are transported through an alkaline solution from a cathode to an anode.
In contrast, in anion exchange membrane electrolysis (AEM), an anion exchange membrane is used to separate water molecules (H₂O) into hydrogen (H₂) and oxygen (O₂).
Finally, solid oxide electrolysers use a solid ceramic material as the electrolyte, which conducts negatively charged oxygen ions.
Each of these technologies has certain advantages and criticalities, so it is important to choose the most suitable one to use according to the needs and specifics of the system to be built. That is why it is important to turn to a competent and reliable partner who can recommend the most suitable technology for your needs.
Simplifhy, the partner for the realisation of your plant with PEM technology
Simplifhy is able to support companies in the design and realisation of technological solutions for hydrogen production, including plants with PEM electrolysers.
Therefore, we are a strategic partner for companies and institutions interested in contributing to decarbonisation and energy sustainability through the use of hydrogen as an energy carrier and alternative fuel.
Specifically, we support you in the entire process of building a hydrogen production plant, from the feasibility study to the design and engineering phases, through to commissioning and maintenance.
Contact us to realise your plant with PEM technology.
