They don’t even come close to making sense for existing houses. For building a place far from utility lines, they might make sense.
Since commercial buildings have economies of scale and do not get a “base amount” of cheap electricity like houses do, you will know these are ready for prime time when businesses start installing them.
High capacity lithium-ion batteries remain quite expensive.
For emergencies and travel use, and really as a toy, I was lucky to get one of these guys lightly used for half off:
It is a really cool product created on kickstarter if you want to dip a toe into solar powered batteries. You can use the phone app to see how fast it is charging and/or how fast it is draining and comes with 100% of what you need to use it in a slick and tough outdoor-proof package.
