But you still need the grid. That's the kicker. You needs to spend billions to keep the exisiting utility grid infrastructure in place. That makes a difference on the incremental costs. Right now it looks good to be a small-scale generator tied into the grid because, one, in many places, the law forces the utility to take the small genrator's power when it is available, and, second, the ubiquitous "someone else" picks up the cost of maintaining the grid.
There is no "storage" in the grid, unless there's something like a pumped storage reservoir available (there aren't many, relatively speaking). Electrons put out on the grid are used by the systemwide load as they are supplied by the sources.
True.
But by reducing the amount of power needed at peak air conditioning times we can put off construction of expensive major power plants.
Solar power doesn't quite make sense on any level, but it is getting closer...