Where is balance Academic priorities 272

I just recently purchased a package of them; the one I have on my computer desk as a backlight is on 24-7 (11W) and I can close my fist around it without problems.

watt - a rate of energy flow (say x electrons per second)

watt hour - the above running for an hour. (an hours worth of x electrons per second)

kilowatt hour - a thousand of the above.

If you have a 1000 watt lightbulb and run it for an hour, you've used up 1 kwh of energy; a 2000 watt lightbulb run for half an hour also uses 1 kwh.

So saying the fridge is an 800Watt model is useful for the electricians who have to wire the place, but if you want to know how much it's going to cost to run over a given time period, you have to know how much of that time period the fridge is actually going to be on (since when it's not refrigerating no electricity is being used).

Of course a set of *useful* metrics would be: efficiency of the refrigerating method; efficiency of the insulation. (with honourary mention to: speed of refrigeration; slowness of dissipation with the door open)

KWH is what electric co's charge by.

rpl