Saturday, October 29, 2011

Phantom power - should we care?

I wanted measure the relative electricity consumption of various devices around the home, especially with regards to the so-called phantom power.  Phantom power is a power draw used by devices that are plugged in, even when they are not actively turned on (like televisions, VCRs which do nothing except for display the time, and computers). You've probably heard the occasional reminder from your power company about the significance of phantom power.  I've wondered just how significant this is to our power usage, so I bought a power metering device from Zellers.  It provides the real-time power usage of any device plugged in.  Here's some data:
Compact fluorescent lamp: 19w
My Windows Mobile PDA on, and charging: 12w
Same, only charging and not on: 1w
24" LCD monitor, on: 22w
same monitor, off: 0w

Yamaha 67 key musical keyboard (on): 7w
Same, off: 3w
PC: 9w when off, 112w when on
laptop (on): 53w

Phone charger (microUSB), nothing plugged in: 0w

Phone charger (microUSB), phone plugged in: 3w

The phantom power of a bunch of devices plugged into my computer power bar 17w
Phantom power of a bunch of devices plugged into my media centre: 22w

BC Hydro charges our home a basic fee, and a variable fee.  The variable is $0.0667 per kWh.  A kWh is the amount of energy used by 1000W for one hour, or 100W for 10 hours.

As far as phantom power on all my devices goes, that's about 40w * 720h = 28.8 kwh , or less than $2, which is basically not all that significant, costwise.

D complains whenever I need to leave the computer on overnight, so I calculated that for 8 hours:
112/1000 * 8 * 0.0667 = $0.06.  For those who leave your computers on 24/7 for the the entire month, this is $5.38.

Where is most of our power going then?
lighting - incandescent bulbs are notoriously inefficient
cooking - there's a reason they're plugged into 240v outlets

We don't use the drier, and seldom use the dishwasher, so none of our power is going there.

As an experiment this month, we've refrained from switching on our home heating (forced air) and will only use  electrical heating (portable space heaters) for our home.  When our next bill comes, we will compare it with the same period last year where we used our home's gas heating (which doesn't work very efficiently anyways in our home) and will compare costs.  I suspect the cost difference will be less than $10 since our regular variable rate for gas is also quite low.  If so, the savings won't be worth the inconvenience of lugging our space heaters around and the temporary pain with leaving our localized warming areas.

**all costs are minus HST**

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