My rough estimate is that 14kw should power a 10,000 btu AC for about 10 or 12 hours. Maybe less if you arent supposed to go below 20 or 30%. I could be way off, im no engineer. Will you need to replace it in 10 or 20 years? Prices and capacity are improving fast, but I'm not sure it beats my $48/mo electricity cost on $8k install. It will eventually, I bet. But then if you could sell back power, the solar cells could probably help pay for themselves if grid tied. Sort of shame for kw of solar just sitting out there, doing nothing.
But modern advances in batteries makes off grid far easier. If you had something > 1 mile from a line, if was formerly about impossible to get economical power. Now you can. That's really cool for the boonies. Again though: off grid is best where you can do wood & propane heat, and electric isn't so damn important.
I will also say this, down below ground, deep deep, where the worm people whisper, requires no power to cool or heat at all. Mother earth's coddling bosom. It calls to me. Does it call for you, too?