I guess, but single full size panels generally put out 30-50v, and efficient batteries are usually 48V, so you’d need transformers at least, and the strings coming to our house are generally 350-500V. Newer high voltage battery packs operate at 400V+.
Not to say it’s impossible to run a DC circuit at 12V or less, but wire is expensive, and lower voltage means thicker wire.
A boost regulator to convert 30–50V to 52V or whatever the battery charger needs is probably cheaper than a transformer, and already available as an off-the-shelf part, or you can jugaad it with a few extremely common parts. In this case we don't need the galvanic isolation provided by a transformer.
Heh fair, but point was more that you'd need other components that add to the cost, and for Americans, they probably want to stick with UL listed bits installed by an electrician. But yeah, for someone off-grid or otherwise not subject to rules as strict as US code, maybe?
The NEC lets you do almost anything up to 30 volts and doesn't regulate what's inside the appliances you plug into your outlets, just the wiring that's part of the building.
I thought it was up to 48 volts, but it looks like NFPA 70 Article 725 Class 1 circuits are only up to 30 volts, and there's a power limitation I didn't know about: only 1000 VA. So you can only run a pretty small storage heater from a Class 1 circuit, and even Class 1 circuits have some safety requirements: https://www.ecmweb.com/cee-news-magazine-archive/article/208...
Class 2 and Class 3 also require the use of a listed power supply.
Unfortunately, I think Americans are much too heavily invested in current infrastructure to consider going all-in on those…