Plug in batteries where the battery itself is cheap af (like Australia) and the ability to charge it for free from the grid exists (like Australia) are a no brainer. When batteries are expensive and grid electricity is not free (the entire US) then it doesn’t really pencil out and requires the plug in solar but that has to be cheap too. Think used panels off Facebook marketplace type cheap. Like I don’t care about offsetting a portion of my energy for free with a 7-10 year payback. Plug in systems should pay for themselves in less than 2 years IMO.