by Ishaan Goel
The second article in this series on water electrolyzers focused on polymer electrolyte membrane electrolyzers (PEMEs). PEMEs have increasingly captured the interest of industry over recent years, due to favorable technical characteristics. Despite this, the global electrolyzer market today is dominated by a much older model – alkaline electrolyzers (ALKEs). (For details of how both electrolyzers work, refer to the first article in the series).
The graph above shows the investment costs ($/kW) of ALKEs and PEMEs as the technology has advanced over time. In other words, they show the initial capital cost for every 1 kW of electrolyzer capacity. The bubble size represents the total operational lifetime in hours of the technology, which is an indicator of its durability. The costs are mostly for ‘stacks’ – bundles of electrolyzers with higher…