calculating electricity costs

Ian King IanK at
Thu Mar 11 11:53:34 CST 2010

> -----Original Message-----
> From: cctalk-bounces at [mailto:cctalk-
> bounces at] On Behalf Of Brian Lanning
> Sent: Thursday, March 11, 2010 8:33 AM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: calculating electricity costs
> Suppose my power company claims that the charge is $0.02407 per
> killowatt/hour.  If I have a computer (or anything) that draws maybe
> 100
> watts.  that should be 0.1kw/h x 0.02407 x 24 hours = 5.7768 cents per
> day
> or $1.73 a month.  I've been under the impression for quite some time
> that
> it costs $20 a month to run a typical modern desktop computer 24 hours
> a day
> for a month.  I know there are taxes and fees thrown into the power
> bill.
> But what's wrong with my math?  Was I wrong before or am I wrong now?
> I got
> this kw/h price from the power company web site burried in a pdf
> somewhere.
> It looked like the right price to me.  Maybe the actual charge is much
> higher?
> brian

Here in Seattle, they charge progressively: 4.39 cents per kWh for the first 10 (summer rate) or 16 (winter rate) kWh per day, then 9.14 cents per kWh for everything past that.  You're right, that sure seems to add up quickly.  I have one of those inline meters that not only tells me the rate of consumption but also allows me to accumulate it over a period of time for periodic consumption (like a refrigerator, that cycles on and off).  It's been helpful in terms of making decisions regarding 'optional' equipment - like the dual-proc Alpha machine that draws 250 watts....  -- Ian 

More information about the cctalk mailing list