This Space for Rent


At home, I run a couple of servers 24x7. One of the servers is our main connection to the outside world, and it does remote backup of the two public servers that sit downtown, so I can't really turn it off, and the other server is the network backup for the first one, so, because I've got a somewhat stupid rsync backup scheme (rsync, because it's Open Source®™©, does not come with the most coherent documentation, so once having set up a working backup system, I really don't want to go back in and tweak it so that I can have the backup machine turn itself on, do the backup, then turn itself off.) These servers consume 104 watts, or about 75 kwh/month.

We also have a (single) desktop machine that sits up in the library, leaning out the window and calling "hooyoo!" like a Bourbon Street prostitute. Because we're lazy, we never turn it off (if we turned it off, we'd lose our ssh connections back to Pell), so it consumes 94 watts every day and every night, for a total of 68 kwh/month.

This costs us about US$12/month to run the machines (and this is down from the US$20 or so it used to cost before I bought a couple of kill-a-watt units and went on a soviet-style energy audit.) This is about 20% of our monthly energy consumption (the major part of our electricity bill is an electric water heater which has been eating, like clockwork, between 400 and 500 kwh/month) and it was originally my plan to swap it over to a solar/wind generator array to get everything except kitchen+heat off the grid. At least that was the plan; the reality is that to save US$12/month (and to save it in such a way that I can take advantage of all of the rebates that are available), I'd need to spend between US$6000 and US$14000 (I'd get back between US$5000 and US$8000 in federal and state tax credits, which are certainly nothing to be sneezed at, but I'm still out US$bignum to begin with.) And at US$12/month, that means that I'd recoup the initial investment in, um, 55 to 100 years (and, since today is conveniently my birthday, this means I could celebrate break-even day on my 101st to 146th birthday.)

Nnnnnnnnnok. And these figures are for grid-tie systems, aka "no grid == no power" unless it's between 10am and 3pm. Perhaps it would be worth my while to try and figure out a way to keep ssh connections from timing out when you disconnect a machine for 16 hours.


I don’t close up my laptop when I’m not using it mostly because I have two windows with “tail -F /var/log/*” going on on two different systems and I can’t be arsed to re-open those windows, su and type “!tail” on both of them twice a day. That’s more than a little bit lazy, I guess.

Paul Tomblin Mon Jul 31 18:18:23 2006

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