/life/metrics/Is Your Refrigerator Running?
Why yes, it is!
Not only that, but Between January 18th at 12:10 and the 31st at 13:00, it used 32.39kWh, or about a buck fifty of electricity. That's an average about 103 watts. Unfortunately this period was biased by a brief period (12 hours? We're not sure) where the volume of groceries in the freezer exceeded its capacity and it ran non-stop.
When running, it consumes about 236 watts. Assuming this value is fairly steady (it's an old fridge, so I imagine it occupies only two states in the on-off spectrum), it's on about 44% of the time.
Our last electricity bill was 1183kWh over 66 days, an average of 747 watts, so the fridge uses about 14% of our power. Except that measurement problem listed above, but I think that should be relatively small.
Another way of looking at this is that it's about 900kWh per year, or 75kWh per month; the sticker inside says 110kWh per month, so it's actually over-performing, which is surprising. Perhaps it's rated against a higher indoor temperature than we keep.
A quick perusal of Future Shop's refrigerator selection shows that modern fridges seem to be rated between 400 and 480 kWh/year. That's 40kWh/month at the most. So, assuming those numbers are accurate, we'd save 35kWh/mo, or about two bucks. At that blistering pace, the fridge would pay off in about 16 years.
I'll have to take the same measurement in the summer, when things are a little less refrigerator-friendly round here.
Comments
Josh wrote
Actually, the fridge would never pay off, since you get the energy savings, but your landlord has to buy the fridge.
Rob wrote
I was actually assuming I'd pay for the fridge myself, if it would mostly-pay-back within the year. Not so keen on that now. It's probably way way more worthwhile when it's 25-30 degrees in the summer instead of ~18, since if the fridge is cooling to 5 degrees, that's 20-25 degrees of cooling vs ~13, so nearly double.
Tony wrote
Mostly this entry amazed me by how bloody cheap electricity is. Look at the world map skewed by electricity consumption: http://www.sasi.group.shef.ac.uk/worldmapper/images/largepng/117.png
Rob wrote
pedantry: it's actually production, not consumption; for most countries that's not a big deal, but France exports a fair bit of electricity, I believe.
See http://www.sasi.group.shef.ac.uk/worldmapper/textindex/text_fuel.html
