## quick numbers for electrical usage

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• I calculated this for my own use, and thought it would be helpful for others. \$.14/kwh (going rate in Houston) 120 watts * 24 hours/day * 30 days/month = 8,640
Message 1 of 3 , Jul 6 8:23 AM
I calculated this for my own use, and thought it would be helpful for
others.

\$.14/kwh (going rate in Houston)

120 watts * 24 hours/day * 30 days/month = 8,640 watt hours / month
8,640 watt hours / month = 86.4 kwh / month
86.4 kwh * \$.14/kwh = \$12 / month

So, if you have a 120V appliance/lamp/whatever that uses 120watts of power
(for instance, a light fixture with 2 60 watt bulbs), and you leave it on 24
hours a day, it'll cost you \$12 a month.

Since 120 watts at 120V is 1 amp, if you do measurements at your breaker box
(using a clamp-on amp meter, or "clampmeter"), you can see that each amp of
measurement (assuming it's for a constant, 24 hour/day load) will cost you
\$12/month.

You can extrapolate this, of course. For instance, if you have a light with
a 60 watt bulb, and you have it on for about 6 hours a day, it'll cost you
Or, if you're like me, and you have a couple of computers that you leave on
24/7, and they draw around 3 amps total, then that's costing me about
\$36/month to run them.

Paul

----------------------------------------------------------------
"All right...initialize the GBL."
"How do you do that, then?" Terry Pratchett
"It...it means pull the great big lever." from "Hogfather"
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• ... You re correct, in that 6,640 watt hours would be 8.64 kwh. I had a typo in my original numbers. That should have been 86,400 watts. (120 watts * 24 hours
Message 2 of 3 , Jul 6 9:39 AM
12:04pm, ChasMauch@... wrote:

>
> In a message dated 7/6/06 10:41:24 A.M. Central Daylight Time, tigger@...
> writes:
>
> 8,640 watt hours / month = 86.4 kwh / month
> 86.4 kwh * \$.14/kwh = \$12 / month
>
>
>
> I thought a killowatt = 1,000 watts
> so 8,640 watt hours = 8.64 kwh * \$.14 = \$1.20 month
>

You're correct, in that 6,640 watt hours would be 8.64 kwh.
I had a typo in my original numbers. That should have been 86,400 watts.
(120 watts * 24 hours * 30 days).

Paul

--------------------------------------------------------
Never trust a computer you can't repair yourself.

Paul's Corollary:
Never trust a computer that's been repaired by its user.
--------------------------------------------------------
• Don t forget about the P3 Kill-A-Watt meter. Very cool device to measure how much power something uses over time. I bought mine on Ebay last year and I love
Message 3 of 3 , Jul 7 7:52 AM
Don't forget about the P3 Kill-A-Watt meter. Very cool device to
measure how much power something uses over time. I bought mine on
Ebay last year and I love it. They don't make one for 220 yet.

http://www.p3international.com/products/special/P4400/P4400-HG.html

Thanx

--- In hreg@yahoogroups.com, Paul Archer <tigger@...> wrote:
>
> I calculated this for my own use, and thought it would be helpful for
> others.
>
> \$.14/kwh (going rate in Houston)
>
>
> 120 watts * 24 hours/day * 30 days/month = 8,640 watt hours / month
> 8,640 watt hours / month = 86.4 kwh / month
> 86.4 kwh * \$.14/kwh = \$12 / month
>
>
>
> So, if you have a 120V appliance/lamp/whatever that uses 120watts of
power
> (for instance, a light fixture with 2 60 watt bulbs), and you leave
it on 24
> hours a day, it'll cost you \$12 a month.
>
> Since 120 watts at 120V is 1 amp, if you do measurements at your
breaker box
> (using a clamp-on amp meter, or "clampmeter"), you can see that each
amp of
> measurement (assuming it's for a constant, 24 hour/day load) will
cost you
> \$12/month.
>
> You can extrapolate this, of course. For instance, if you have a
light with
> a 60 watt bulb, and you have it on for about 6 hours a day, it'll
cost you
> Or, if you're like me, and you have a couple of computers that you
leave on
> 24/7, and they draw around 3 amps total, then that's costing me about
> \$36/month to run them.
>
>
> Paul
>
>
>
>
> ----------------------------------------------------------------
> "All right...initialize the GBL."
> "How do you do that, then?" Terry Pratchett
> "It...it means pull the great big lever." from "Hogfather"
> ----------------------------------------------------------------
>
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