The automatic power on backups can get quite pricey. Generac make a unit that will power your whole house,,, for extended time. Of course the price for that will scare you out of your hatching$$$$$$$$$ :old :gig
The link you posted is fine,, but only for very small power consumption...
You have actually 2 options.... Differently priced also.
First option, would be to get a generator, and this way, during a power outage, you still also have electricity for the rest of your home. Limited to of course the power output of unit. I have a generator, and have used it on...