Power Crazy

Some girls buy perfume and shoes - I've just bought a Power Mate Lite - and as that old credit card ad used to say, "I never leave home without it".

When I'm not using it for home assessments, I've been plugging it into anything that will stand still long enough at home, to measure power consumption. Dad made an early departure in the Winnebago on Tuesday - wonder if the two are related? (He's not too quick on his feet these days........)

My average daily electricity usage is about 3.7 kWh of which about half is the fridge! (More on fridges next time). If you're curious about yours, it's always recorded somewhere on your electricity bill and you can go to my Eco Toolbox for more info, if the thought of understanding your power bills thrills you.

The average Qld household of 2.5 people uses about 21 kWh a day (but in SEQ we are closer to 30 kWh/day thanks to our fondness for air conditioners). On most bills, 4-10% of this daily figure is 'leaked' out of things that aren't even being used - ie appliances in standby mode, turned off with the remote, showing a little light or time indicator, off at the button but on at the wall etc. To understand what this means cost-wise, we need to understand.....

"The Hour of Power"

As well as being Jimmy Swaggart's equivalent of happy hour, it's also the way we are billed for electricity. It's pretty straight-forward. Most appliances are measured in 'watts' - ie the amount of electricity they need to run (check a few labels for the 'w' figure). Electricity companies bill us for power in units of kilowatt hours (kWh)

1 kWh is the same as saying you are using 1,000 watts of power for one hour.

An example:

A 100 w appliance running for 10 hrs would use 1,000 wh (or 1 kWh) for which you are probably charged about .18c by AGL or whoever.

So my mission today was to find out how much money I was wasting by paying for electricity being leaked from my appliances via standby power (often called 'vampire power' - in which case I think it should be measured in killer-watts) But I digress ...

Here's what I found out.

My laptop uses between 20 and 36 watts when running - so not quite 1c an hour. A desktop computer with an LCD screen is about 3x this, and the older type (with the monitors that are shaped like ET's head) are about 4x. But there's also a subtle little energy-leak when I'm not using it too (I'll add up these red figures for a yearly total of standby power, at the end)

Up until a while ago, when I finished using my laptop, I'd turn it off but leave it plugged in at the wall, say for 10 hrs at night. My power meter recorded that this was drawing a bit under 1 watt of power, not much to write home about on it's own, but we'll add it in anyway...

Standby:

1w x 10 hrs = 10 wh /day (or 3,650 watt hours / 3.6 kWh per year)

My hand-me-down mobile phone (which I detest in principle, but seem to have to have) I use as an alarm clock as well, so it's charging for 8 hrs a night (about 45 watts in total, or 1 cent for the night). When I unplug it, I usually leave the charger plugged in at the wall and switched on ...

Standby:

.2w x 16 hrs = 3.2 wh / day (or 1,168 wh / 1.2 kWh per year)

I was interested to see what my 10 yr old Sony equipment was using in standby mode (TV, amp, speakers, DVD and CD players). I used to turn the whole lot on and off with one remote because the wall switch was hard to get to. On average I only use this equipment about 3-4 hrs a week (ok, a bit more when Master Chef's on) - let's be generous and say an hour a day. 1 hrs use /day x 192w = 192 x 365 days (70,080 wh / 70 kWh/$12.60 / yr)

But get this - the system used to use more power just sitting there for the other 23 hours of the day, than when I actually used it!

Standby:

23 hrs x 15w = 345 x 365 days (125,925 wh / 125.9 kWh / $22.66 / year)

My old-school CRT TV accounts for about 60 watts of the 192 watts of power the whole system draws when it's on. Compare similar size TV's in other technologies here (then do a search on big plasmas!) Remember the energy consumption is based on 10 hrs a day use, so divide by 10 to get hourly figures. ie: in that list, my TV would show up as using about 219 kWh /year - 60 watts x 10 hrs/day x 365 days) You can see LCD and newer LED tellys are so much more efficient again, but I'm not going to "upgrade" - not really a TV fan anyway. But I do switch it all off at the wall these days and watch the TV without the sound coming through 'the system' unless it's a movie so I only draw 60 watts of power not 192! (scroll down for a neat little power board option)

Moving on to the 'other half' of my office - my phone and modem (plus an all-in-one printer not in photo). I could save energy by using a plug-in Telstra phone, but I like to be able to move around (ie: outdoor office above) so this set-up is my little luxury. Let's see what it's costing me to have a phone, modem and router running 24/7, and a printer plugged in to the same power board but switched off 95% of the time. Not really a standby scenario, but they are things that I could easily switch off except for when I'm using them, (if I was so inclined).

To leave running:

15w (total) x 24 hrs = 360 wh /day (131,400 wh / 131.4 kWh / $23.65 year)

MORE THAN ALL MY OTHER STANDBY APPLIANCES PUT TOGETHER!

So, adding all the kWh amounts up, my gadgets in standby mode (and phone/adsl setup) are using about 262 kWh a year - that's $47 - ish of my annual electricity bills (or more importantly about .7 kWh of my 3.7 kWh daily usage) When you're trying to make your solar panels work as efficiently as possible, all these little bits add up, so I might have to rethink the phone/modem set up.

Standby can account for anything between 4 and 10 % of a normal household's electricity usage - don't know about you, but I'd rather have that money than give it to my electricity co.

To reduce your 'vampire power', get into the habit of turning things off at the wall and check out standby power boards like this where you have a lot of office or entertainment equipment plugged into a hard-to-reach wall switch.

My website has some other useful resources for measuring what appliances cost to run. Did you know some air conditioners, washing machines and dryers also 'leak' energy while they are sitting quietly in the corner?

Next time... fridges. Have a great weekend and don't forget to turn the telly off at the wall! :)