how do I figure the cost of watts?

naturist wrote:

ken white wrote:


X2 and the units of energy are the Joule...

:B

Yes, Ken, the units of energy are joules. And kilowatt-hours. And BTUs, calories, ergs, and more.

Just as the units of length are inch, foot, yard, micron, angstrom, light-year, parsec, etc.

The units used in the US for electricity by the electric power industry, and by which consumer's bills are calculated, are kilowatt-hours. This leads to the simplest calculations, but if you want to do the complex ones, you can insert the unit conversion factor in the there. Don't forget to do it twice, once for the energy used, and again for the dollars-per rate. At which point, if you set up the right algebraic formula, you will find the two cancel each other out, and you wind up with what you had to begin with. But it's your call.

It should be noted also, that the units are NOT kilowatts. "Kilowatts" is a rate, like speed, and to get to the right place, you MUST specify a time, too. If you don't figure out how many watts and how much time, you can't answer the question of how much it will cost. It is like asking if I go 60 miles an hour, how far will I go? No time specified, no answer possible.

Same question: if I sometimes turn on a 0.1 kilowatt light (that's a 100 watt light bulb), how much will it cost me? No time, no answer.

DryCamper11 wrote:

ken white wrote:
X2 and the units of energy are the Joule...

Energy can also be measured in kilowatt hours, which is what most people doing this type of calculation use. :)

The conversion is 3.6 million Joules = 1 kilowatt hour. A single watt second is a Joule, so the number of seconds in an hour times 1000 gives that number.

Tough crowd, and I know all of the conversions... :B

The engineer in me likes to reinforce SI units since they are used almost everywhere in the world. For some reason, we can't seem to embrace them in this country even though they make much more sense. Off my soapbox and thanks for making my point.

:B