Sounds like one of the least efficient energy storage ideas I've heard in a long time, I wonder how this is getting funded? Hmm, let's check to see who is behind this...the founding professor https://www.tue.nl/en/research/researchers/philip-de-goey/ is a fellow/awardee of the Combustion Institute, gets funding from ERC, etc. OK, so I guess all that European taxpayer money won't spend itself, and if you have a hammer blah blah nails...
They're a bit further along (scaling up from low-volume production, some installs in the wild) with a different approach to the use of iron (flow batteries).
ESS should not be mentioned except as an example of how prone the green news cycle is to fraud. As I detailed last year, their claims are highly dubious:
(previously I misspelled the last name of Sri Narayanan as "Narayan", for which I belatedly apologize)
And that prediction was substantiated when they were subject to a class-action shareholder lawsuit in February involving a fabricated customer which was actually a subsidiary:
Yes, this is a strange approach. Separate iron from iron oxide, which is energy intensive. That's what blast furnaces did, or do, and it's a messy and energy-intensive process. Burn iron to get heat and iron oxide. Repeat.
Are there numbers on the energy efficiency and costs of this process? This seems very strange. Batteries are above 90% round-trip efficiency now. This has to be lower.
Meanwhile, stationary class (i.e. relatively poor energy density) iron air batteries are making commercial progress. https://pv-magazine-usa.com/2023/06/12/form-energy-to-deploy...