ah, fair enough. The design in the photo is much more vertical than horizontal- maybe they're designing for space constraints? I would imagine 500*C molten salt

ah, fair enough. The design in the photo is much more vertical than horizontal- maybe they're designing for space constraints? I would imagine 500*C molten salt would be significantly more efficient than sand, so the only charitable thing I can come up with is they're simply putting the cheapest materials they can (discard sand, free electricity) to good use.