Just some quick thoughts on how to reduce electricity consumption at home. These figures are very rough-and-ready (but do come from 9 day’s of monitoring with IAMs… but usage was a little unusual over the Christmas period):

  • 10 x 12V 50W halogen kitchen down-lights on TRIAC dimmer (currently 1kWh/day = £50/yr). These are the biggest single power draw in our house. I’m currently researching LED or CFL alternatives.
  • Central heating and hot water pumps (combined currently 0.6 kWh/day = £27 / year). Replace with energy efficient pumps (these cost about £100 IRC, so payback for 2 pumps would be ~9 years).
  • washing machine (currently 0.5 kWh/day = £22/yr) fit hot water feed with mixer. Heating water with a local gas boiler is more carbon efficient than using resistive heating.
  • dishwasher (currently 0.6kWh/day = £27 / year) fit hot water feed and disable hot air dryer somehow?
  • 34” CRT TV (currently 0.5 kWh/day = £22 / year) upgrade to LED LCD TV (32” LCD TVs use about 40W) (notes)
  • Dual-core Athlon HTPC circa 2006 (currently 0.6kWh/day = £27/year). Upgrade to 22nm Atom when it’s available.

Raw consumption data from 9 days of usage after the break…

Ignore the “count”, “SAMPLE PERIOD” and “% missed” columns - these are just there to help me keep an eye on my data logging system.

Start 2012-12-25 17:53:14 End 2013-01-04 08:00:06 Duration 9 days, 14:06:52 ———- ———————

POWER (W) SAMPLE PERIOD (s)
\# name count min max min mean max % missed kwh
1 aggregate 128193 154.0 4700.0 5.0 6.5 148.0 7.7% 91.0
2 boiler 135574 0.0 117.0 5.0 6.1 37.0 0.4% 5.2
3 solar 135573 0.0 59.0 5.0 6.1 37.0 0.4% 0.2
4 laptop 133887 12.0 102.0 3.0 6.2 84.0 0.2% 3.4
5 washing\_machine 134057 0.0 3051.0 3.0 6.2 17.0 0.1% 4.1
6 dishwasher 134078 0.0 2772.0 5.0 6.2 13.0 0.1% 5.1
7 tv 133165 0.0 1412.0 3.0 6.2 770.0 0.8% 4.7
8 kitchen\_lights 133242 0.0 468.0 5.0 6.2 457.0 3.7% 9.5
9 htpc 133626 0.0 167.0 3.0 6.2 122.0 0.5% 7.1
10 kettle 133970 0.0 2608.0 3.0 6.2 54.0 0.2% 2.4
11 toaster 134056 0.0 2730.0 3.0 6.2 25.0 0.1% 1.3
12 fridge 133583 0.0 1838.0 3.0 6.2 204.0 0.7% 8.4
13 microwave 134075 0.0 2798.0 5.0 6.2 13.0 0.1% 1.2
14 lcd\_office 134062 0.0 2787.0 3.0 6.2 16.0 0.1% 0.7
15 hifi\_office 134072 0.0 14.0 4.0 6.2 13.0 0.1% 0.1
16 breadmaker 134083 0.0 663.0 4.0 6.2 13.0 0.1% 0.6
17 amp\_livingroom 133792 0.0 48.0 3.0 6.2 201.0 0.3% 0.9
18 adsl\_router 133341 5.0 134.0 3.0 6.2 71.0 0.9% 1.4

The HTPC and TV usually use less than listed above but I recently had to fix our HTPC which required that it be on constantly for about 48 hours.