I also don’t like the fact that it’s a mechanical device that will just sit there until needed. Is it going to be in good working order when the time comes? If I haven’t kept up on the maintenance and testing, maybe, maybe not.

Solar panels sit on the roof and you watch the graph rise and fall throughout the day. You should wash them about once a year, but they’ll still do an OK job if you don’t. That’s pretty much it.