Power usage results…


With the aid of the power monitor plug, the results below indicate how much power is consumed by a variety of electrical products. From this, wehave already implemented some changes.

For electricity, the real emissions vary year on year due to the different mix of fuels used in the power stations and are average grid figures. However, the figure quoted for electricity is 0.43kg CO2/kWh which has been held constant since 2000. This value is used by DEFRA to ensure a consistent base on which to measure savings and was calculated on the projected fuel mix for the grid 1998-2000. Actual figures may differ from the projections, but DEFRA plan to use a constant value for environmental reporting until the year 2010.

If you wish to convert the carbon dioxide factors into carbon equivalents (ie kgC/kWh) , multiply the figure by 12 and divide by 44.

NEC AccuSync 72xm LCD monitor
Test period (2 hrs)
Normal use: 0.03kwh
Energy saving mode – light goes orange (19 hrs): 0.02kwh
Screen switched off but plugged into wall socket:

Macintosh G4
Test period (24 hrs)
Turned off but left on at the plug: 0.06kwh

HP JetDirect 175x
Test period (17 hr)
Normal use: 0.05kwh

HP Laserjet 1200
Test period (16 hr) – standby
Normal use: 0.08kwh

Test period (24 hr) – standby and normal days use
Normal use: 0.16kwh

CONAMATIC coffee machine
Test period (2 hrs)
Normal use: 0.33kwh
(mixture of standby with hot plate on and filtering of 1 jug of coffee)
Energy consumption to make one jug of coffee (7 mins): 0.11kwh

Nokia phone charger
Test period (6 hrs)
Charging mode: phone fully charged, but kwh doesn’t even register!
Plugged in but not charging (17hrs): 0.01kwh

Netgear 10/100 24-port switch
Test period (2 hrs) (4hrs)
Normal use: 0.05kwh (0.10kwh)

Buffalo AirStation
Test period (4 hrs)
Normal use: 0.02kwh

Test period (3 mins) – full
Normal use: 0.16kwh

Test period (? mins) – 1 cup
Normal use: 0.??kwh

Test period (2 hr)
Normal use: 0.04kwh

Old fridge
Test period (90 hr)
Normal use: 1.6kwh

New fridge
Test period (24 hr)
Normal use: 0.23kwh

Electric fan heater
Test period (30 mins)
Normal use: 0.78kwh


2 Responses to “Power usage results…”

  1. Simon Says:

    Are these figures the total enery consumption over the monitoring period? For example, the figures for the electric fan heater are: 0.78kwh and 30mins. Does this mean that if you left it on for 1 hour it would consume 0.78kw?

  2. rackandruin Says:

    The test period is the amount of time I monitored it the device for and the ‘Normal use’ figure is the amount of energy the equipment consumed over that test period.

    So in the electric fan heater example, it used 0.78kwh over 30 mins. If I’d monitored this for 1hr, it would’ve used about 1.56kwh. In fact I think I did, but it scared me too much!

    As you can see on the Netgear 10/100 24-port switch, I monitored it for 2hrs and then 4hrs and the amount of energy consumed after 4hrs was double what it was after 2hrs.

    So it seems to make sense.

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