Alkaline electrolyser stacks for green hydrogen production

EHSQ AWARENESS

About Alkaline electrolyser 

An alkaline electrolyser stack performs well for green hydrogen production, particularly in large-scale applications, due to its established technology, lower cost, and ability to operate reliably with fluctuating renewable energy sources, although its efficiency may be slightly lower compared to other technologies like PEM electrolysers; however, recent advancements are improving its performance and efficiency, making it a strong contender for cost-effective green hydrogen production. 

Key points about alkaline electrolyser stacks for green hydrogen

Mature technology:

Alkaline electrolysis is a well-established technology with a long history of use, leading to greater reliability and easier maintenance compared to newer options. 

Cost-effective:

Utilizing inexpensive materials and catalysts, alkaline electrolysers generally have lower capital costs compared to other technologies, making them attractive for large-scale projects. 

Scalability:

Due to its design, alkaline electrolyser stacks can be easily scaled up to produce large volumes of hydrogen, suitable for industrial applications. 

Operational flexibility:

Alkaline electrolysers can handle fluctuating power inputs from renewable sources like wind and solar, allowing for better grid integration. 

Lower efficiency:

While cost-effective, alkaline electrolysers may have slightly lower electrical-to-hydrogen conversion efficiency compared to PEM electrolysers, especially at high current densities. 

How it works:

Electrolyte: An alkaline solution (like potassium hydroxide) acts as the electrolyte, allowing the flow of hydroxide ions (OH-) between the electrodes.

Hydrogen production: At the cathode, water molecules are split, releasing hydrogen gas and generating hydroxide ions.

Oxygen production: At the anode, hydroxide ions are oxidized, producing oxygen gas and water. 

Recent advancements:

Pressurized alkaline electrolysis:

Newer designs incorporate pressure to improve hydrogen production efficiency and enable direct storage of hydrogen at high pressure. 

Improved catalysts:

Research is focused on developing more efficient and durable catalysts to enhance overall performance. 

Considerations when choosing an alkaline electrolyser stack:

Application size:

Best suited for large-scale green hydrogen production due to its cost-effectiveness and scalability. 

Power source stability:

Performs well when paired with stable power sources like hydroelectricity or grid-balanced renewable energy. 

Operating conditions:

Consider factors like water quality and required hydrogen pressure when selecting an alkaline electrolyser system.