Joy of joys, last Sunday I went into Dyas and found that they now stock plug-through energy meters for £10 apiece (apparently £13 on the website).
First device to get measured up was the fridge, which we found to be consuming about 0.4 KWh per day (average over a 4 day period). We took a vacuum cleaner hose to the coils at the back, and found that the usage dropped to about 0.33 KWh per day (also measured over 4 days).
Next up is my computer. Even before anything was switched on, I was finding a draw of 11 W, which I guess is just the power supply keeping itself alive. Once the computer is switched on and settled down, this is up to 70 W. Turning on the monitor takes us up to 110 W, speaker system up to 113 W, desk lamp up to 160 W.
I was surprised by how much more energy the computer consumes than a fridge. We are always being told how the fridge is such a significant slurper of juice, yet having a computer on round the clock equates to having five fridges, and that’s without the monitor switched on. Putting it into standby or hibernate mode obviously reduces this greatly, but that’s not much help if you are actually using the thing. Maybe our fridge is just phenomenally efficient. Your mileage will vary, obviously – the odds are that your computer isn’t an AMD Sempron 3000+ with three hard drives in it.
What should I measure next?
10 replies on “Consumption”
Kettle. Iron. Laptop. TV.
> Kettle
Easy. The kettle has a peak power of 3 KW. If the thing takes a minute to boil, this means that the maximum possible energy used is 0.05 KWh. So the daily savings generated by cleaning the coils on the fridge corresponds to two kettle-boils, maybe a little more.
> Iron
We have one of these devices, but we never use it.
> Laptop
We’re definitely going to measure the power used to charge Karen’s mobile phone, but we might do the laptop too. Nice suggestion.
> TV
Okay, 9-10 W to power the VCR and DVD player on standby. Putting the TV on standby ups that to 11-12 W (less than I was expecting). Switching the TV on takes us up to about 55-65 W, depending upon how bright the image is on the screen.
Ugh, I did not want to see the program that is on channel 5 right now.
Yeah, we save a lot of energy by the way we use our iron. It hasn’t been out of its box in 18 months.
I want to measure the slow cooker. Shame we can’t compare it with the oven, but I don’t think that has a plug. Or does it? If so, I would like to do a casserole comparison.
I also want to see a chart of the results.
> I want to measure the slow cooker. Shame we can’t compare it with the oven, but I don’t think that has a plug. Or does it? If so, I would like to do a casserole comparison.
The oven does have a plug, but it’s down in a cupboard and quite hard to reach.
There is a difficulty to measuring the slow cooker – because the sockets in our kitchen are immediately under the cupboards, we can’t plug the energy meter in directly. We’d have to employ a short extension lead. Not insurmountable though.
> I also want to see a chart of the results.
I want to visit the owls.
Speaking of owls, we bought an OWL electricity monitor before Christmas, and it’s been really useful.
We get similar results to yours, depending on what’s on – the OWL has a monitor on the cable coming from the electricity meter, so you get to see the full power amount being used at any time – although the PC is a bit lower (In fairness, not by much)
I now check the monitor every night before bed – it’s a useful way of knowing quickly if anything’s been left on, for example- and it’s certainly changed some of the things that get left on etc.
Don’t bother with the mains adaptor optional extra. I bought it, and we haven’t used it yet. Leave the thing on batteries, and it seems to be fine.
Yes, I’d seen those kinds of electricity monitors, but decided not to buy one as I wanted to examine the individual appliances. I suppose you can achieve the same result just by turning appliances on and off and then remeasuring, but that involves lots of running around the house.
Wii. Xbox. Charging Nintendo DS. Charging 4xAA rechargeable batteries.
> Wii. Xbox. Charging Nintendo DS.
I don’t have any of those devices, but I believe that the Sony PlayStation 2 is rated at 50W, so should be in the same ballpark as my television.
> Charging 4xAA rechargeable batteries.
This will vary depending upon your battery’s capacity. 2400 mAh batteries will take 3 times as much energy as 800 mAh batteries. I’ll add it to the list.
Fair enough, re the OWL etc. – we wanted to keep track of total usage rather than on a per-item basis, so for us it’s worked out OK.
As for items to test, if you’ve a DECT phone / answerphone, it might be interesting to see how much that takes. Probably not much, in fairness.
How about mobile phone chargers, if they’re just left in the socket and turned on? (Which was one of the ones always marked as “Big Sin”)
> As for items to test, if you’ve a DECT phone / answerphone, it might be interesting to see how much that takes. Probably not much, in fairness.
I was thinking about this, but to get to the socket where the answering machine is plugged in would require the moving of a heavy piece of furniture. In the interests of energy conservation, fuck that.
> How about mobile phone chargers, if they’re just left in the socket and turned on? (Which was one of the ones always marked as “Big Sinâ€)
It’s already been done