How often does your power cut out unexpectedly and how bad is that for you and your website? For me in the Netherlands, maybe 2 years ago my power cut out for

How often does your power cut out unexpectedly and how bad is that for you and your website? For me in the Netherlands, maybe 2 years ago my power cut out for an hour IIRC. Pretty reliable, good enough for my website to be just as available. Point being: is it worth the effort to have a backup in that circumstance?