I did a little bit of digging on this and if it looks like sand batteries are a subcategory of thermal batteries, which in their turn are part of what is called thermal energy storage . Wiki mentioned something that I found fascinating and that I totally didn’t know:

Thermal batteries are very common, and include such familiar items as a hot water bottle. Early examples of thermal batteries include stone and mud cooking stoves, rocks placed in fires, and kilns.

Ok so it looks like they try to shift to the sociocracy model.

Coincidentally, I have a friend who worked for some years in a company that was trying to shift from a typical hierarchical structure to a co-op with a horizontal decision-making processes, using sociocracy. For them, and to my understanding, it was not going great. They actually kinda kept replicating the typically centralised structure for too long but this time using the “circles” deriving from sociocracy. That said, maybe by now they have managed to move on from this transitional phase, but I don’t know since my friend doesn’t work there anymore. That said, from the conversations we had, I got the understanding that there has been successful approaches in other coops, in the sense that they had achieved consent-based decision-making processes.

This could be a promising project. If anyone knows what is the decision-making processes within this community, could you share a link?