ive in a hurricane zone nx anything that would keep an AC going would be a BIG sell...
To keep a central unit going with whole house generator runs about $10,000. Waaaay too much for something used every few years...
But what would it cost for solar to keep one window unit or duckless system running until power was back on?
Lots of folks in Florida are ready and willing to buy.
There are portable ductless mini-split units that sit on the floor, with an intake hose and a hose for moisture condensate, both of which would be routed through a panel in a window, similar to how a window unit is placed in an open window. These use the least amount of power. Have to be level, though, or condensate is going to leak.
The problem with trying to run an emergency system off of solar would be that you’d want a battery bank sufficient to run it through the night. By the time you get all that set up, it doesn’t make sense to only use it when the power’s out, you’d want it grid tied to reduce your electric bill. Also, your exposure to sun would need to be good, with a clear southern exposure not blocked by structures or trees or other plants.
There are numerous RV’s around with solar and battery banks now that are sufficient to run the air conditioning through the night, so it is possible, but those systems are also backed up by a generator typically. It’s not easy to answer. Here’s a description of a 2,000 watt solar system with a 1200 amp hour lithium ion battery bank on a 41’ Newmar motorhome that powers the air conditioning:
http://precisionrv.com/2017/08/24/2000-watt-1200-amp-hour-newmar-motorhome-solar-power-system/
The cheapest thing you could do would be to have a generator panel wired specifically to run a portable ductless mini-split or window unit, plus a few other things, a few lights, couple of electric outlets so that a smaller, much cheaper generator could definitely run it. $10,000 for a whole house generator to run your whole house just for an occasional power outage is excessive and really a luxury. You’re only wanting to make a room habitable, not power the entire house. Ask a reliable, trustworthy electrician what the cost would be. It’s hard to give a pat answer to any of this because what would need to be done would vary depending upon your needs and circumstance, but it would certainly be far less than $10,000.
To keep a central unit going with whole house generator runs about $10,000. Waaaay too much for something used every few years...
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I think you aren’t looking very hard. I bought a 16KW Generac system including an automatic transfer switch for just over $3000.00. I had to install it myself but it isn’t rocket science.
I also have whole house solar. I have 12KW PV on the roof. That means about 60KW per day in sunshine. On a hot day in the summer my usage is higher than 60KW with a/c but the utility company takes my extra on good days and gives it back to me on the bad days.
I think if I had it to do over again I would have put 15KW on the roof but finding that much south facing roof is a problem.
When not using a/c or heat pump heating I make a lot more than I use, even on cloudy days except on laundry day with the electric drier, that and a/c at the same time really use it, over 10KW an hour.
My battery will last about a week, I found out the hard way when I had a setting in the control system set for battery priority instead of utility during a rainy week. Anyway if needed I could run the generator for about 5 hours and get two days out of the battery, much longer out of the battery sans a/c. I really expected the battery to last longer, I could push it a few more days but it is really hard on the battery to do that. The charging system is only about 80% efficient so that even if you make 60KW you will only be able to store about 48KW of that. One thing that helps is that during the day you use it as your making it, of that you are about 98% efficient. Most of my use is in daylight hours.
It has been fun, it has not been cheap. ROI is several years. I wanted it for security not ROI. Do it yourself solar is not for the weak hearted but it is VERY satisfying.