Calculating the quiescent power consumption of my house

[vortex2]

I've been losing sleep on this:

• There are 8760 hours in a year.

• A unit of electricity costs (say) 8p

• So 1 watt of household quiescent consumption costs 70p per year.

I have more wall warts and other items, permanently on in the house than ever before and they're always warm (the linear ones at least).

ADSL Router Ethernet switch USB Hub Printer Various lights Answering Machine Bell Transformer Aerial Amplifier power. TV on standby x 2 Sky box Bedroom Freeview box Drill Charger Assorted clocks/clock radios ....and no doubt lots more. The list goes on.

That's a lot of 70p's in the course of 12 months. I am going to have to get out my Maplin power meter and add all this up. I have a hunch I am in for a shock.

Anybody out there done this exercise for themselves? What was the outcome?

[John Laird]

It's probably not worth losing sleep over ;-) You might find you are "wasting" 20 quid per year, but since that's less than half a tankful of petrol or diesel, try to put it into context.

You can judge the total more easily by watching the meter go round, having first temporarily switched off likely interruptions such as fridges and freezers and central heating pumps. But your power meter will be useful to identify what makes up this "base" load.

Thinking about it, only. But please post your results.

[Dave Plowman (News)]

You need to ask yourself what the options are if you actually need such things. Some need permanent power because of clocks etc but many don't. There's no need to leave chargers switched on when not in use, for example.

[The Grim Reaper]

I'm working on it... I've got posts in sci.electronics.basics - about reading the flashing LED installed on some electricity meters, and keeping track of my power usage!! I've gone from basic voltage comparators to a full blown microprocessor project now... I'll let you (all) know when it's done!! _______________________ Grim

[Dave Liquorice]

Most of that list you can't do much about, expecte don't leave TV's in standby switch 'em off. Any chargers switch off/unplug when not actually charging something.

I doubt that a Mplain power meter will be particulary accurate at low power levels. Probably easier to count disc rotations or LED flashes to see what your "base load" is.

[tony sayer]

In article , The Grim Reaper writes

And the consumption of what thats going to take!....

[Calvin]

Don't forget that the "wasted" power is heating your home so for at least half of the year it's not really wasted at all - it is causing your boiler to switch off that little bit sooner. Of course it's a little bit more expensive than the heat from your boiler but not much.

[PhilC]

Our new LCD TV & HDD recorder have according to manufacturers a standby consumption of 1 watt.each

PhilC

[Mathew Newton]

Remember however to bear in mind that much of that 'waste heat' is actually contributing to warming your house up over the cold(er) months... (and unless you've got aircon it won't be doing much 'harm' during the summer).

Mathew

[Ian Stirling]

Sorted probably into something resembling order.

I would be surprised if these totalled 10W.

Probably around 25W

These vary - many'll use 1W or so when off, a laser printer, used sporradically can be very much higher.

Add them up, and consider replacing any which are consistently on for >5 mins with CFLs. And turning them off when not used.

It depends, if fairly new - probably under 20W.

Probably around 60W.

This'd come to 120W for all of it apart from the lights.

A hundred quid a year ish.

Of course, the trivial answer is 'turn it off when you don't use it.'.

The harder answer is to consider how to reduce power use, while not impacting things.

Switches help of course.

For example, the sky box will be deeply upset by actually being turned off at the mains, and will take around a minute to wake up.

If they would actually publish power numbers on small appliances, then you could pick lower power ones.

For example, my ADSL router uses 7W. It cost 30 quid. If I could have known that the 35 quid one would use 5W, then it'd be a win - as it'd pay back in 3 yearsish.

An ADSL router + switch may take 8W, rather than 7W for an ADSL router, or 15W for seperates.

Unfortunately, it's almost impossible to actually find out real power use for stuff you're going to buy. This is one area where the government could actually make a useful contribution, mandating standby power consumption numbers on things.

[Dave Fawthrop]

|I've been losing sleep on this: | |* There are 8760 hours in a year. |* A unit of electricity costs (say) 8p |* So 1 watt of household quiescent consumption costs 70p per year. | |I have more wall warts and other items, permanently on in the house than |ever before and they're always warm (the linear ones at least). | |ADSL Router |Ethernet switch |USB Hub |Printer |Various lights |Answering Machine |Bell Transformer |Aerial Amplifier power. |TV on standby x 2 |Sky box |Bedroom Freeview box |Drill Charger |Assorted clocks/clock radios |....and no doubt lots more. The list goes on. | |That's a lot of 70p's in the course of 12 months. I am going to have to get |out my Maplin power meter and add all this up. I have a hunch I am in for a |shock. | |Anybody out there done this exercise for themselves? What was the |outcome?

As has been said repeatedly here all these things heat the house for 8 months of the year, so I ignore the costs.

Don't try turning off the Sky box or TVs they are designed to stay on standby and forget important information when switched off, then go into startup mode when power is restored which is a right pain in the *rs*.

[JellyBelly]

Sky box, yes, I agree, and in my case also the DVD/HDD recorder, because both of them download new EPG listings during the night. In fact, my Sky box has to be left *on* (not just in standby) and tuned to British Eurosport (channel 410) because that channel carries the GuidePLUS+ information that the DVD/HDD recorder needs to download each night.

But TVs? TVs can be switched off at the mains with no problems, unless these new-fangled plasmas and LCDs have something that I don't know about - which is possible as I'm on widescreen CRT and will be for a few years yet.

JellyBelly

[John Rumm]

Stick a clamp meter rount one of the meter tails - darn site easier that measuring each devices consumption one by one.

No, stuff is plugged in because I want it that way, so not much point in counting the cost.

[Pete C]

Give up the telly. There's a lot of time/energy/money saved right there!

Also replace your router/switch with a USB modem and software firewall ;)))

cheers, Pete.

[manatbandq]

If your TV is absent minded then it probably needs fixing.

Our Freeview boxes run quite warm in standby but can be switched off at the mains with no probs.

MBQ

[The Grim Reaper]

PIC chip - takes approx 40uW... i.e. not a lot :P ____________________________ Grimch