This question came up on a forum I’m on. It turns out it’s really quite easy to work out — this page covers pretty much all the details.
In addition to what’s there, it’s worth noting that the current Irish price for a kilowatt-hour under the <a href=’http://www.esb.ie/main/energy_home/ef9.jsp’>ESB’s domestic rate is 12.73 cents per kWh, which works out as 14.41 cents per kWh once the 13.5% VAT is added in. So Irish users, pretend you live in New Hampshire (15 cents per kWh) to get realistic figures from <a href="http://michaelbluejay.com/electricity/howmuch.html#4″>the excellent cost calculator.
Using this, it looks like if I was to leave an 160W desktop computer on permanently in Ireland, I’d be spending 215 euros per year to power it. Wow, that’s pricey! My strategy of using low-noise, low-power hardware for home servers has paid off already, in that case. ;)
For what it’s worth, if you’re worrying about the power consumption of an NTL digital Pace Digital TV set-top box — if <a href=’http://energyefficiency.jrc.cec.eu.int/pdf/Presentation_EC_meeting_11-04-03KD.pdf’>this Pace presentation is anything to go by, it appears the standby power consumption is on the order of 1-2 watts — about 2 euros per year. Grand.