electricity usage puzzle

[Tracy]

Hi I have a friend who has decided to try and cut down on his gas and electricity usage so has been reading his metres twice daily (sad, I know :-) ) He has gas for central heating, hot water and cooking. He has discovered that between the hours of 22:00 and 10:00 he uses 6 units of electricity and between 10:00 to 22:00 he uses about 8 units. So in a 24 hour day he uses 14 units. This means that during the day when his TV and sky box is on he is using 2 units of electricity more than if he just had on what is using electricity during the night.

He has had his meter checked and it is OK

He does not have an immersion and the only electricity used at night is lights, TV and fridge freezer and if the heating is on his central heating pump although the TV and lights are usually off by midnight as is the central heating. At first he thought it could be his security light but that has been turned off and disconnected. Before he goes to his bed he switches everything off that is on standby, even pulling the plugs out, so as far as he knows the only thing using electricity at night is a couple of clock radios and the occasional light when he or his wife gets up to the loo.

So he has deduced that during the hours off 22:00 and 10:00 he is using on average 500 watts of electricity every hour. He read his meter again one night before he went to his bed at midnight and had used 1.5 KW in the preceding 2 hours, switched everything off and went to his bed. When he got up at 08:00 he read his meter and found he had used 3.5 KW in 8 hours during the night so has anyone any idea what could be using this electricity between these hours?

There is no immersion heater, his shower is a power shower using hot water heated by gas, the only water heated by electricity is his kettle and there is no one boiling water during the night. When the washing machine and tumble dryer are used there is a noticeable increase of units used during the day and they are not used at night. He has even gone so far as to pull the plugs out at night and when anything is not being used. He is completely baffled as to what is going on and using electricity at night.

Me, I'm convinced that he is taking all this energy saving too far and should be quite happy that he is only using 14 units of electricity a day.

Thanks for reading this and suggestions welcome, even the bizzare, Tracy

[Andy Hall]

Last of the big spenders :-)

Yes, it's because he's unplugging things. If the plugs are left in the sockets it prevents the electricity leaking out of the sockets.

Definitely the plugs. Either that or his Mrs. is sleep tumble-drying.

Quite so. There are group help meetings of an organisation called Eco Anonymous for this. He'll find kindred spirits there - people with

60cm of loft insulation, triple glazing, that kind of thing.

They recite mantras along these lines:

"My name's Jim and I'm an ecoholic"

"Hello Jim"

and so on.

[Roger Mills]

The one thing which *is* potentially on all the time is the fridge/freezer - but I doubt whether that would use an average of 500 watts because it should be switched off by its thermostat quite a lot of the time.

May be worth buying a little plug-in meter from Maplins (or similar) which can measure the amount of electricity used by a single device over (say) a

24 hour period. Plug that into the fridge/freezer and see how much it actually uses.

The other thing to do is to go round turning everything off, and make sure that the little disc in the electric meter actually stops going round. If it is still moving, some electricity is being used *somewhere*. Could there be an attic light left on by accident, or something like that?

[Lurch]

On Sun, 8 Apr 2007 22:40:25 +0100, "Roger Mills" mused:

Greenhouse heater, tube heater in an outside lav, some heater somewhere that has been forgotten about, erratic immersion heater timer....... could be anything.

[Michael Chare]

I would suggest turning off various circuits at the consumer unit to find out which circuits are responsible for the power consumption.

I use about 12 peak and 2 off peak units per day - summer and winter.

[Tim Lamb]

In message , Lurch writes

Door bell transformer? Often forgotten but hardly a major load.

regards

[Dave Liquorice]

So:

750W/hr when he is awake with lights & TV on.

440W/hr "switched off".

How many fridges or fridge freezers or freezers does he have? When the compressor is running they take around 150W. Are they properly and regularly defrosted? How old are they?

You say he goes around unplugging everything does that really mean

*everything*, the TV, the sky and/or freeview box, the VCR, the DVD, the broadband router, the PC, the PC monitor, PC speakers, USB hub, network hub/switch, cordless phone base unit, cordless phone charger unit(s), mobile phone charger(s), telephone answering machine, bedside clocks or clock radios, burglar alarm, mains powered smoke detectors, the list is huge. If anything is connected and on it'll be taking something, even if it's a only a couple of watts, they all add up.

Doesn't have a "keep warm" function does it?

Quite we use nearer 24 units/day...

[dom]

I use 3.5units/day.

[The Medway Handyman]

I always suspected that was the case. Would PTFE tape around the pins reduce the leak?

[Bob Eager]

36 units/day here...!

[Stuart B]

Fish tank lights/heater /Filter/Air Pump ?

[tom.harrigan]

Rumour has it that some Sky boxes consume power at the same rate on "standby" as when switched on.

I think what you mean is that his average power consumption between these hours is 500Watts?

I think what you mean is that he had consumed 1.5kWh in 2hrs, which means his average power consumption was 750Watts.

If he went to bed at 24:00, and had used 3.5kWh of electricity between then and 08:00, then he was consuming less than 0.5kW.

I believe tha average UK household runs at a bit below 0.5kW, so your friend isn't consuming an outrageous amount of electricity. What he/ you/we may have discovered is that fridges+standby consume a surprisingly large percentage of our daily electricity. Central heating timers, Sky boxes, phone chargers, fridges, and other background use seem to add up to 0.5kW in your friends house. It's only 2Amps, but it is a bit worrying.

Tom

[Clive Mitchell]

In message , Tracy writes

For that level of load the disk in the meter will spin at a modest rate. He could narrow things down by checking the disk speed in the evening when the fridge is not running and if he believes it to be turning faster than expected he could turn off whole circuits at the consumer unit to see which affects the speed of the disk.

Don't rule out the possibility of a neighbouring house having a socket tapped off YOUR power!

[George]

House,flat,bungalow,spacecraft,houseboat?

Sounds like the substation is giving him full belt in the elecy at the day time peak?

[Andy Cap]

Or socially responsible ! ;-)

I would firstly suspect the fridge/freezer.

Andy

[Andy Burns]

Only the round-pin plugs (don't use the thick ptfe for gas) the square-pin ones you should use boss-white instead.

[Mary Fisher]

Congratulations to your friend for his decision and his readings aren't at all 'sad' but sensible. If he hadn't done that he wouldn't have known about the differences in usage you've spent so long typing. ...>

It will be even better if he can use fewer, surely?

Mary

[dennis]

Not anymore. They do do some power saving these days. They do keep the LNB powered and receive stuff from sky at night.

[Andy Hall]

[fido]

Perhaps in the loft? What about the chap who got so frustated with not being able to find out where his power was being used, he switched off everthing at his main switch and discovered all the street lights down his side of the street went out.

Years ago I was a caretaker in a country club. I switched off the power in my flat one day as I wished to do some electrical work. The club oil fired boiler stopped working! Only a pump, but they were using my electricity. After the club secretary admitted it the wiring got changed.