If you are in the process of purchasing an electrolyzer, you’ve probably already reached the part where manufacturers tell you that electrolyzers have a lifespan of 80,000 hours, does that sound familiar? And does the phrase, “…or 10 years, whichever comes first” ring a bell? This eventually leads to the well-known re-stack, which you might have also heard of. Re-stack refers to replacing the electrolysis stacks when they reach the end of their useful life (as we’ll cover this in more detail in another blog post, we won’t go into it further here).
When an electrolyzer reaches the “end of its useful life,” we see, at first glance, two options. Two second lives or perhaps, it would be better to say, one dignified way to die and another dignified way to, shall we say, stay in service, but in a secondary league?
The first is to recycle them. Depending on the technology, there may be: steel, gold, titanium, iridium, platinum, cobalt, nickel (Have you seen how nickel prices have risen due to the invasion of Ukraine? Have you noticed the trend in lithium prices over the past few years?).
That said, doesn’t it seem quite sensible to recycle them? According to a 2019 NREL study, a PEM anode uses, on average, 7 grams per square meter of platinum and 4 grams of platinum-iridium for the cathode. Additionally, there are the bipolar plates, end-plates, etc.
The second is to reuse them. Here, a very big WARNING. What we say here does not, by any means, replace what the electrolyzer manufacturer advises, but just as there are increasing projects to repurpose lithium batteries from electric vehicles for energy storage projects, what about stacks, for example, of 1 MW that are replaced by more modern and efficient ones but are still functional? Couldn’t they be given a second life by reducing their current density? In other words, making them operate as if instead of 1 MW stacks, they were perhaps 500 kW or 300 kW stacks. Obviously, the performance of the stack would be reduced, but so would the price. We believe it’s at least worth considering.
In short, for now, we see two options for “retired” stacks: one, to recycle them and recover the rare/expensive materials. Two, to reuse them. The choice will depend on:
– Who is willing to buy them: those interested in the first or second option, and when we have buyers for both types.
– Who offers more money.
We hope you found this entry helpful. As you can see, we know quite a bit about the topic, and that’s because we’ve been in the business for a long time.
If you have a hydrogen project or want to start developing one, we can help. Your hydrogen department, with three decades of experience, at your service.
Write to us at info@leanhydrogen.whdev.es or call us at +34 619 952 889 and ask for Eugenio. Visit our website to find all the blog posts and much more: www.leanhydrogen.com
Image by AWOE: A World of Energy.
