I wonder what it would cost to go solar off grid?聽 聽The pay back timeline may shorter than I think.
I've seen 4.5 KWH systems for about $9000.聽 If you have any experience pulling wire, installation doesn't seem all that difficult.聽 If the terms "inverter" and "transfer switch" are just so much gibberish, you'll want to secure the services of a licensed professional.
I have also seen subsidy and rebate programs.聽 My suspicion there is that you would purchase a solar power package from an island company who would do the install.聽 Expect the initial price to double, though you should recover some of that from the subsidy/rebate.
Rey is correct that you would want a battery.聽 When the grid is up, your solar panels will engage in "net metering" which means that if you produce more power than you use, your meter will run backwards.聽 In effect, your solar cells are just one more power generating plant contributing to the grid.聽 However, when the grid goes down, your solar cells will do nothing.聽 To fix this, you run the power through a battery.聽 In normal operation (with grid up) you do net metering.聽 When the grid goes down, you power your house off the battery and use your solar panels to keep the batteries charged.
The Tesla battery that Rey mentioned looks pretty good.聽 It's lithium, not lead cell, so no nasty gases.聽 If I recall, a battery runs about $5000.聽 Don't know how long they are expected to last.
In short, low-end cost looks to be about $15,000.
I plan on installing just such a system.聽 While the initial price is a little high, there's no need for a generator, and I expect my electric costs to be near zero (apart from the basic charge).聽 I'll also install a solar hot water heater, a cistern for potable water (through a reverse-osmosis filter) and greywater landscape irrigation.聽 My goal isn't to live "off-grid" but merely to be both economical and prepared for either service interruptions or price hikes.
Update: Found the link for that solar package.聽