Electricity consumption of kilns

[Steve_K]

Just a general question, can anyone give me a swag (scientific wild assed guess) at the cost of running one 10 hour long, typical firing on a 120v/15 amp Paragon Gf-7 kiln? I just moved into a house and don't even have a feel at what the typical monthly bill is for electric. Is it somewhere around a dollar a day? or .25 cents a day?
I looked through the old archives at some of the kilowatt testing equipment, etc., but I don't think I want to go that far. A friend uses a really small kiln and says it hardly affects her bill at all, she claims to have called the power company. Just wondering if I should be splitting the bill evenly or not. Thanks![/i]

[Phil Hoppes]

Here is a way to guess. The ACTUAL answer requires a little more data. Your particular kiln is a 120V/15Amp kiln. This means your kiln requires 1800 Watts or 1.8KW (KiloWatt) when it is ON. When you fire for a 10 hour cycle, your kiln is not ON that entire time. The most accurate way to measure your on time is to attach an AC timer to your controller. This would require you to crack open your controller case and do some wiring which I would say is only for the electrically inclined. For the case you describe I will just make some educated guesses. On your ramp up I'm going to assume you will get to temp in 4 hours. That is a 400dph ramp to 1500 degrees. I will assume that during this ramp up your kiln will be on approx 50% of the time. You have 6 hours left on your cycle. This is your cool and anneal cycle. For this period I will place a guess that your kiln will be ON for 25% of this time. Totalling up your total On time we have .5x4hours + .25x6hours or a total of 3.5hours. Now you need to look at your last electric bill and see what you pay per KW/Hour. It should be listed somewhere on the detail of your bill or you should be able to call your electric utility and they should be able to tell you. For this example I will make a guess of 8.5cents/KW-Hour. Now you take and multiply your cost per KW-Hour by your total ON time, in this case 3.5 hours and your power your kiln consumes when it is ON, which we said is 1.8KW and you get:

$0.085 x 3.5 x 1.8 = $0.54 (rounded)

So if my guesses are close on both your on time and your cost for electricity, your kiln should cost you a little over 50 cents every time you fire it for a 10 hour cycle.

Actually milage may vary..........

Phil

[Steve_K]

Brilliant reply Phil, just what I needed to know. Thank you very much! Your #'s sound accurate, I will check my bill.

[Victoria Nelson]

A simple way to arrive at a 'guestimate' firing cost is to record your electrical meter reading at the start and finish of firing. Subtract the meter reading start from the finish to give you the kilowatts used. Check your electric bill for the cost per kilowatt and wah la.
Its close to the cost of electricity consumed for glass firing unless your doing a Betty Crocker cook off at the same time!

[Kitty]

depends on how much your electricity is. my little kiln costs roughly 35 cents for an hour firing, and my big kiln runs somewhere between $7 and $10 for about 12 hrs. the little kilns are cheap to run.

[Phil Hoppes]

That works assuming you don't have an AC unit. If you do anything that is major electric (hot water heater, AC Unit, Electric Range) you would want to be sure you don't have it kick on while you are firing or it could mess up your data. That being said, that is a clever and quick way to get a close estimate. A closer way would be to see what you consume during a typical 10 hour period. Then do the same thing with your kiln firing. The difference should only be due to your kiln and that will get you an even closer number.

Phil

[Cindy next door]

I think I got this info from the archive awhile back. Although it doesn't take into account actual firing time, it does cover wear and tear. The thread walked you through the figures very well. This is my format for figuring my 1414 costs.



Skutt 1414 Kiln Firing Cost

Kiln Specifications

Kiln Volts Amps Watts
GM1414 220 34.7 / 40 8320

Wattage Divided by Equals Kwh
8320 1000 8.32


Electricity Cost - August 2002
SRP $0.09 Cost per Kwh of Electricity

Wear & Tear
Cost of Kiln Total Firings Cost/Firing
$1,308.55 400 $3.27


Cost per Firing
Kiln Kwh Hrs in Firing Kwh $ Cost / Firing
8.32 6 $0.09 $4.49


Cost per Load
Cost / Firing Wear & Tear Cost/Load
$4.49 $3.27 $7.76

Cost per Piece
Cost / Load No. / Pieces Cost/Piece
$7.76