Yeah power is a major cost factor and was always included with every colo quote
we've ever received. It's not important if you have a little server with one or two
hard drives pushing huge bandwidth (a typical porn site). The bandwidth bill covers
the power usage when you have a lot of bandwidth. For a backup server, there's
very little bandwidth so power becomes the largest cost, along with space.
Will, I think you'll very much want to look into Clonebox:
https://bettercgi.com/clonebox/
Clonebox will give you all of the advantages you'd have buying and coloing a separate
backup server, at a lower cost, and with state of the art software systems to keep
your spare server ready at all times. For example, it's very common that people make
one huge error with backup. They backup daily, say at midnight. At 11PM, a cracker
wipes out the site. When they notice that, at 6AM, the backup has already run and
you have two copies of crap. Your expensive backup has done you no good whatever.
Clonebox keeps FOUR copies ready to boot at any time, so you can boot the server
as it was last night, the night before, last week, or last month. That's one little
example of one of the many things we take care of for you so you have a state of
the art solution, and it costs you less than buying, hosting, and maintaining your own
dedicated spare server.