Will Smith - Climate Change - Electricity Consumption of Common Domestic Appliances.


I measure the electricity consumption of household devices in my home and other devices I come across from time to time.  I hope this information is useful to others.   The devices are grouped acccording to where in the house they normally live.

Computer Room
Lounge / Living Room
Kitchen / White Goods
Miscellaneous

In summary, the highest power usages over 24 hours are as follows (only including the items I still have, some have been disposed of or were not in my house in the first place):

Device Power Usage per 24h
(in kWh)
Comment
Electric shower 2 to 3 estimated Yet to work out how to measure this, but I think it's a lot.
Large PC, always on, media and internet server 2.42 Expensive but inevitable.  It cannot 'hibernate' or 'standby' since it's regularly accessed by other machines over the network.  Downloads and backups are scheduled for overnight so 24 hour operation is essential.  Possible solutions are to get a later processor that supports dynamic CPU scaling and voltages, so it runs slower when not in use.
Combined Fridge / Freezer 0.80
Kettle 0.75
TV (21", analogue) 0.42 This could  be reduced slightly by turning off at the plug when not in use.  Standby power is only 5% of full power.
PVR (personal video recorder, hard disk based, in lounge) 0.41 Surprisingly high usage.  Another always-on device.  Can be scheduled to standby when not recording, but then tends to miss some recordings.
Wireless ADSL Router (always on) 0.29 Providing wireless and internet capability to several PCs in the house.  Slow to boot up.  Easier to leave on.  Does get hot - perhaps not a good model.
20" Computer Monitor 0.27 But I could reduce this to 0.19kWh if I always turned it off manually not in use rather than relying on standby.
Washing Machine (assume 1 load every 3 days) 0.26 Less greedy than most people might expect.

Changes
Version 1.0 - 27 February 2005.
Version 1.1 - 28 February 2005.  Added typical kettle usage stats.
Version 1.2 - 1 March 2005. Tidied up some 24 hour averaged power consumption stats.
Version 1.3 - 2 March 2005.  Italics where it clarifies what's changed.  Clarify where 24h total power is estimated, and where it's measured.
Version 1.4 - 22 March 2005. Added long term TV usage, listed items using most power.
Version 1.5 - 15 July 2006.  Added new monitor, printer, iron.
Version 1.6 - 3 Jan 2007.  Added new fridge.
Version 1.7 - 6 Oct 2010.  Moved to new house.  Likely to be lots of updates including things I've bought over last 3 years.


Computer Room




Device and Usage
Power Usage Comments / Conclusion
Laptop Computer


(Acer Travelmate 290E, Celeron M @ 1.3GHz, 14” screen)
on, not charging, no disk activity, no cpu activity, display on medium, blue background 15W
brightest screen uses 4w more than dimmest
on, not charging, no disk activity, no cpu activity, display on dimmest, blue background 13W

on, not charging, no disk activity, no cpu activity, display on brightest, blue background 17W

on, not charging, no disk activity, no cpu activity, display on medium, white background 15W

on, not charging, no disk activity, no cpu activity, display on medium, black background 15W
dark background colours gives no benefit
on, not charging, no disk activity, no cpu activity, display on medium, blue background, screen blanked 10W
screen on uses 3w, normal 5w, bright 7w
on, not charging, no disk activity, heavy cpu activity, display on medium, blue background 25W
full cpu uses 10w more than quiet cpu
on, not charging, no disk activity, no cpu activity, display on medium, blue background, disk spun down 14W
hard disk uses 1w when on but idle,
on, not charging, heavy hdd activity, no cpu activity, display on medium, blue background 20W
and 6w when heavily used
on, not charging, no disk activity, no cpu activity, display on medium, blue background,cdrom playing music 21W
cdrom uses 6w when playing music
on, not charging, no disk activity, no cpu activity, display on medium, blue background, standby mode 3W
standby is quite efficient, considering it returns to active almost instantly
on, not charging, no disk activity, no cpu activity, display on medium, blue background, hibernate mode 3W
Hibernate still uses some power
On, charging, no disk activity, no cpu activity, display on medium, blue background.  Just plugged in (76% charged).
47W
3x idle power when charging.




Small PC


(Aopen XC Cube EZ18, Athlon XP2500+, 1 Hard Disk, onboard graphics, Windows 2000)
Off (from main front switch, PSU switch still left on) 6W

On, monitor on, no cpu activity, no hard disk activity, 1.83 GHz (default)
71W

On, monitor on, no cpu activity, no hard disk activity, 1.1 GHz 62W
slowing down cpu using 'speedfan' can save 9w
On, monitor on, heavy cpu activity, no hard disk activity, 1.83 GHz 97W
fully active cpu uses additional 26w
Peak (booting) 100W

standby mode, S1 type (power on standby) 42W
standby still uses lots of power
standby mode, S3 type (suspend to ram) 7W
Much better standby – important to choose correct type in BIOS
hibernated 6W





Large PC


(Tower Case, used as Server, always on, Athlon XP2000+, 4 hard disks, low end graphics card, Linux)
On, no disk activity, no cpu activity, 1.67GHz 99W

On, heavy disk activity on 3 drives, no cpu activity, 1.67GHz 116W
Each hard disk uses additional ~5w when heavily seeking
On, no disk activity, heavy cpu activity, 1.67GHz 142W
fully active cpu uses additional 42w
On, no disk activity, no cpu activity, 1.67GHz, 3 of 4 hard disks powered down. 81W
Each hard disk uses approx 6w when spinning.
On, no disk activity, no cpu activity, 1.67GHz, CPU underclocked to 750MHz 94W
On idle, slowing the processor further can only save around 5w.
On, no disk activity, no cpu activity, 1.67GHz, 1 of 2 memory modules removed (512mb total, was 1Gb) 97W
Each memory modules uses ~2W
On, no disk activity, no cpu activity, 1.67GHz, geforce 4mx replaced with ati 9600pro 102W
Several different graphics cards have similar idle power requirements.
On, no disk activity, no cpu activity, 1.67GHz, geforce 4mx replaced with voodoo banshee 105W
Several different graphics cards have similar idle power requirements.
On, no disk activity, no cpu activity, 1.67GHz, several motherboard options (sound, firewire etc) turned off 99W
Turning off unessential motherboard options makes no difference.
Total power (measured over 88.5 hours continuous on, mainly idle)

8.91kWh
Average power (averaged over 88.5 hours, mainly idle)
101W

Total power usage in 24h (always on, mainly idle)

2.42kWh




LCD Monitor


(17”, Acer AL1714)


on, typical computer display 28W

on, mainly white pixels 28W

on, mainly black pixels 28W
dark background colours gives no benefit
on, standby mode initiated by computer 2W
important to set computer to power off screen, not just 'blank'
on, standby mode initiated by 'on/off' switch 2W
no better than leaving computer to initiate standby




LCD Monitor
(20”, Dell 2001FP)
turned off using switch on bottom right 0W
on, standby 4W Mediocre standby power, much better to turn off manually.
on, typical screen image 48W
Total power usage in 24h (estimated, assuming 4h on, 20h standby) 0.27kWh Would be reduced to 0.19kWh if I always turned it off manually.
Computer Speakers



(Including subwoofer, Sony SRS-D300)



on, no music
3W


on, moderate volume music
5W


on, moderate-loud music volume
7W


Total power (measured over 11h40, music for ~1 hour)

0.03kWh

Total power usage in 24h (based on average over 11h40)

0.06kWh




Wireless ADSL Router


(Linksys WAG54G)


Off, but transformer (power brick) plugged in 2W
Still usage from power brick.
Wireless disabled, no activity 10W

Wireless enabled, no wireless or ADSL traffic 11W
Wireless on uses 2w
Wireless enabled, wireless activity, ADSL activity 12W
Minimal additional power used when data is flowing
Total power usage in 24h (estimated)

0.29kWh




Ethernet Switch


(D-Link DES-1005D, 4 port, 100mbit/sec)


Standby mode – no network activity 3W

Heavy network activity 3W

Total power usage in 24h (estimated)

0.07kWh
Inkjet A4 Printer / Scanner
(Epson Stylus CX6600)


Turned off at printer 0W
Standby mode 4W
Printing or scanning 14W
Total power usage in 24h (estimated) 0.10kWh Almost never used, much better to turn it on when I need to use it.
Inkjet A4 Printer / Scanner
(HP 6000 OfficeJet)
Standby (enters automatically after some minutes)5W
On, awaiting print jobs6W
Printing20W
Total power usage in 24h (averaged over 24h15)0.14kWhLight home-office use.

Lounge / Living Room




Device and Usage
Power Usage Comments / Conclusion
Digital Freeview PVR


(Humax, model 8000T)


standby mode 7W

on, in main menu 17W
when on (hard disk is spinning) uses
watching tv (and therefore recording) 17W
additional 10w regardless of the activity
timeshifting (both reading and writing to hard disk) 17W

Total power usage in 24h (estimated)

0.41kWh





TV


(Traditional, Analogue, 21 inch)


on, typical viewing 58W

on, most pixels bright 68W
varies depending on amount of bright pixels
on, most pixels dim 50W

standby mode 5W





TV
(Traditional, Analogue, 21 inch, different model)
on, typical viewing 50W
standby mode 3W
Total power (over 78 hours, used day and evening, typical family of 3) 1.38kWh
Total power usage in 24h 0.42kWh
Electric Effect Fire


fire effect only 80W
Surprisingly high 'quiescent' power usage.  Investigation leads to 2x40w non-energy-saving light bulbs.
fire effect + 1 heating element 1000W

fire effect + 2 heating elements 1880W
each heating element is ~900w








Kitchen / White Goods




Device and Usage
Power Usage Comments / Conclusion
Fridge Freezer


(typical, made around 1990, ambient temp=23C


everything off 0W

fridge light on 13W

one or both(?) coolers on 110W

Total power usage (measured over 92 hours)
3.40kWh
Average power  consumption (averaged 3.40kWh in 92h) 37W

Total power usage in 24h

0.88kWh
Fridge Freezer
(Bexo, manufactured 2006, ambient temp=23C)
Total power usage (over 67.75 hours) 2.27kWh
Average power  consumption  33W
Total power usage in 24h 0.80kWh
Fridge Freezer
(Samsung, Manufactured ???, ambient temp=28C)
Total power usage (measured over 92.75 hours)6.66kWh
Average power consumption72W
Total power usage in 24h1.72kWh
Deep Chest Freezer


(Small, made around 1970, ambient temp=23C)


standby mode 1W

Cooling mode, beginning 155W

Cooling mode, later 128W

Total power (measured over 21h30)
2.31kWh
Averaged power consumption (averaged over 21h30)
107W

Total power usage in 24h
2.58kWh




Tall Freezer


(made in 1980's, but leaking door seal, ambient temp=23C)
Cooling power, typical 170W

Total power (19 hours 45)
1.54kWh
Averaged power consumption (averaged over 19h45) 78W

Total power usage in 24h
1.87kWh




Kettle


(typical domestic)


Off 0W

Peak 1900W

Sufficient water for 2 large mugs of tea.

0.09kWh

Total usage (typical domestic use, 3 people, over 57 hours)
1.78kWh
Averaged power consumption (averaged over 57 hours) 31W

Total power usage in 24h
0.75kWh




Sandwich Toaster


(2 toasties at same time)


Cooking 950W

Total usage (two toasties, 10 minutes)
0.09kWh
Averaged power consumption over 24h (assume used once every 2 days) 2W

Total power usage in 24h (assume used once every 2 days)
0.05kWh




Rice Cooker


(typical)


Cooking 495W

Total usage (1 cycle, 30 minutes)
0.43kWh




Washing Machine


(built ~1995)


Off 0W

Water pump only 15W

Heat water 2300W
Despite being connected to hot and cold water. Why?
Rotate drum 250W
But much of time is spent pausing, just brief bursts of this.
Heat water and rotate drum 2550W

Spin (low speed), initial peak 1100W

Spin (low speed), sustained 300W

Total power (1 cycle, 40C, nonfast coloureds, no economy mode, full load, 1 hr 30)
1.06kWh
Averaged power over cycle 707W

Total power usage in 24h (assume 1 load every 3 days)
0.35kWh




Washing Machine


( built ~2001, Hoover Performa 1200)


Off 0W

Water pump only 5W

Heat water 1700W
Again, even if connected to hot water supply (gas, in my house), it does it's own heating (electricity, more expensive).  Crazy.
Rotate drum 150W

Heat water and rotate drum 1850W

Spin (low speed), initial peak 600W

Spin (low speed), sustained 200W

Total power (1 cycle, 40C, nonfast coloureds, no economy mode, full load, 1 hr 30)
0.78kWh
Averaged power over cycle 520W

Total power (1 cycle, 40C, woolens, economy mode (cold wash), 0h50)
0.01kWh Alternative cycle.  Too cold - soap tablet did not dissolve.
Total power (1 cycle, 40C, woolens, not economy mode, 0h50)
0.39kWh Alternative cycle.
Total power usage in 24h (assume 1 'nonfast coloureds' load every 3 days, no economy setting,)
0.26kWh




Microwave


(700w stated output)


standby mode 0W

Full power (9/9) 1150W

Half power, emitter on times 1150W

Half power, emitter off times 40W

Iron
(deLonghi 1600W steam iron)
On, not heating 0W
On, heating 1584W
Total power (35 minutes ironing) 0.13kWh Although irons are high powered, they aren't on much of the time, even when in use.
Total power usage in 24h (assume used 1 hour, once per week) 0.03kWh




Miscellaneous Items




Device and Usage
Power Usage Comments / Conclusion
Battery Charger


4xAA, 5 hour charge


No batteries inserted 0W

Charging 5W

Fully charged, trickle 3W





Mobile Phone Charger


(Nokia 3310)


Charged 1W

Charging 5W

Total usage (1 charge cycle, 3 hours, then unplugged)
0.01kWh
Total usage (1 charge cycle, 3 hours, then idle for 45 hours) 0.05kWh









All content is Copyright 2000-2006 William Owen Smith.   Creative Commons Licence  This work is licensed under a Creative Commons License.