Knowledge is Power
April 22, 2008 by river2sea72
I believe knowledge is power - the power to change our behavior for the better. Driving a hybrid car with dashboard feedback on fuel efficiency lets you know instantly how you can change your driving habits to reduce the amount of gas you use.
What if you could see instantly how much electricity, natural gas, and water you were using in your home? Would you turn off the lights more often? Plug in fewer gadgets? Turn down the gas on the stove when not needed?
To this end, I got myself a new gadget called Kill-A-Watt which provides feedback on electricity usage by standard appliances. So far I’ve tested it on my cell phone charger (0.01 kWh/h) and table lamp with CFL bulb (122.3 kWh/h). I’m going to test more appliances and gadgets around the house and will keep track of the results here. I’m especially curious about comparisons between lamps with CFL bulbs and conventional; computer in active vs. hibernate mode, etc.
In Georgia we are paying about 4 cents/kWh until June. Cost isn’t my concern (I think power is way too cheap), but it is easier to deal with psychologically than kilowatts. I’ll translate the figures to dollars eventually.
Cell phone charger (Blackberry charging and not charging, but wall wart plugged in) = 0.01 kWh/h
Table lamp with CFL bulb = 122.3 kWh/h [I think this is an error - I was looking at the wrong setting]
Computer equipment plugged into UPS = 11.3 kWh/h
To be continued…..
It turns out that you buy energy - there are a variety of units, but calories, BTUs, and watt-hrs are the most familiar. Power turns out to be the rate at which energy is used. Familiar units are horsepower and watts.
So a 100 watt light bulb uses 100 watts of power. If you run it for an hour it used 100 watt-hrs of energy. For a day it is 2400 watt-hrs or 2.4 kilowatt-hrs.
A person who burns about 2300 calories of energy a day is the equivalent of 100 watts of power — so most people use power at the rate of a 100 watt light bulb.
It is good to understand these things so as to know how much energy you are using. We did a careful audit in our about and about 10 percent of the power was being used by the “standby” feature on electronics around the house.
By putting all of our electronics on power switches, replacing our old refrigerator, replacing our desktop computer with a laptop and moving to CF bulbs in most of the house, we were able to drop to about half of our previous usage.
Steve, good point about standby on electronics. I plug mine into a power strip that I can turn on/off at will. Other sneaky power suckers are chargers for mobile phones, digital camera batteries, etc. Most of them use up energy when they are plugged in even when they aren’t charging anything.