"Why does every solution need to fulfill oddball out of the way requirements?"
My oddball requirements would pretty much guarantee full energy independence for 99% of the general population and for 99% of the other 1%, with a proper solar panel array and one of those batteries + inverters per room. Even apartment complexes could utilize this, and so could many businesses. The benefit is expandability and over-storage so you're essentially guaranteed to not run out of power, ever. Modularity means instead of the whole house dying when your single-battery/inverter setup fails (in case your tie-in is faulty, some how,) the rest of the place can actually continue to operate.
Sure it'll be somewhat expensive, but the reduced strain on the battery packs by distributing it across many batteries and inverters will improve the lifespan of those components and reduce the lifetime maintenance costs. Those batteries might last well beyond their warranty period and still maintain a reasonable amount of charge level. The inverters are hopefully still good if they're of any quality.
MESSENGER was over-engineered with the expectation of one year of usefulness. We got more than that, way more. The Rovers were designed for what, six months? We got how long out of them?
Over-engineering is the way to go if you want something to last. Sure, it's expensive, but those savings will become quite apparent in the long run. The way technology is advancing, it's going to become an economic no-brainer soon enough.