What are the 10 states where solar is now cheaper on average than the grid? Arizona, California, Connecticut, Hawaii, New Hampshire, New Jersey, New Mexico, New York, Nevada and Vermont.
See Figure 3 in the linked story to see the 10 states. Just as importantly, take a look at Figure 4 that lists another 13 states where solar will very soon be cheaper than power from the grid. Once solar power becomes cheaper than the grid, it's cost and price advantage over grid electricity will expand and not reverse with the passage of time.
Figures 3 and 4 together show why the solar tsunami heading toward energy markets is enormous and is arriving even now.