My research into this a little while ago showed that this has a very poor energy density to capital cost. There are some other techs like molten salt which are supposed to be better.

I’m not sure this idea is all that they’re marketing it as.

Here’s a video discussing the drawbacks [0], the guy doing the video can be kind of abrasive at times but worth watching/skimming as a counterpoint.

[0]: https://youtu.be/NIhCuzxNvv0

I'd heard of this as a theory many times before, I didn't know someone had actually built one! Good site too, thanks for the link.