Electrical Consumption of Pellet Stoves

Have you ever wondered how much power (watts) your pellet stove uses, or how much energy (kWh) it consumes, or how much it actually costs you on your electric bill to run it for the season? I measured the electricity consumption of several pellet stoves with a P3 Kill A Watt meter and found they average between about 125 Watts to 150 Watts instantaneous power draw depending on the auger and blower settings.

Here's some actual numbers from a 20+ year old Whitfield Advantage II T Insert. During the monitoring period of approximately 2 weeks the stove was running 24 hours a day, only being shutdown for routine cleanings, with the auger and blower speeds being adjusted as usual by the user.

Instantaneous Measurements:
Stove Settings: Auger = 2, Blower = 3

Auger Off Auger Feeding

76 Watts 100 Watts
1.33 Amps 1.71 Amps
159 Volt Amps 197 Volt Amps
.48 Power Factor .48 Power Factor

Electric Rate: 19.1 cents/kWh (Townsend, MA)

Elapsed Time 353 hours (14 days, 17 hours)
kWh's used: 29.81
Total Cost: $ 5.69 (29.81 kWh x .191 = $5.69)

Projected Costs to run stove

6 Months $70.00
1 Month $11.55
1 Week $ 2.69
1 Day $ 0.38

Based on the measurements above I could estimate that this stove uses approximately 2 kWh per day or 60 kWh per month the way the user runs it. Many articles I have read estimate about 100 kWh per month for pellet stoves, which is an acceptible number, but probably a little high.

Surprisingly, my brand new 2010 Harman P35i uses slightly more electricity than the older Whitfield (125 Watts - Auger Off, 150 Watts Auger On), and most notably consumes a significantly higher amount (395 Watts) when using the electric heating element for the auto igniter, but only for about 6.5 minutes when starting the fire. This does not really add a significant cost to the overall electricity consumption however. Here's an example:

395 W x 1 hr = 395 Watt Hours (That's about .4 kWh for roughly 10 fires - 1 hr / 6.5 minutes)

So for every 20 fires, (about 20 days at 1 fire a day) it uses an extra 1kWh to use the auto igniter, which for me costs 19.1 cents - fairly insignificant. I am currently monitoring the Harman P35i, and will post an update when I get some long term readings on its energy consumption.

The Whitfield stove above does not have the auto igniter feature.

Finally, I can say that I have seen a significant reduction in my electric bill by using the pellet stove, as opposed to my forced hot air oil fired furnace. So the pellet stove is saving me $$$ on both heating fuel costs and my electric bill! Awesome

Does anyone else have any measurements on other pellet stoves? I'd be curious to see how they compare to these two.

FYI Here's a link to the P3 Kill A Watt EZ meter I use on Amazon.com
http://www.amazon.com/P3-Internatio...F29Q/ref=sr_1_1?ie=UTF8&qid=1296438867&sr=8-1

Webmaster said:

Nice report!
Previously, we'd only done some calcs based on the claimed usage from the makers. Some pellet stove, like the Englanders, have two feed augers (two motors?) and as I remember some models use 200-300 watts.....in fact, Englander says closer to 350 when used on high.

Taking those numbers, you can end up closer to $30. a month.

I think it is safe to give a range of ten to thirty dollars per month in electricity, most ending up in the middle or lower end due to lower electric rates than yours and less use - very few people would use a stove on high 24/7.

There is at least one model, a Thelin, that claims to use less electric than most...I think about 70 watts.

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Yes, my electric rates are very high... I have Unitil as my power company and our rates are amoung the highest in the country. As a matter of fact, just a few towns over from me in Groton, MA where they have their own municipal light company the rates are nearly half as much - 13.5 cents per kWh, which in turn means that you could run the same stove for nearly half as much.

In fact, the Whitfield stove mentioned above belongs to my Mom. She keeps it burning 24/7, usually on an auger setting of 2 or 3 at the most, and only shuts it down to clean it every week or so.

Jmak135 said:

I was wondering that same thing about the consumption of electricity that was very informative thank you

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You're welcome! All my friends think I'm crazy monitoring electrical consumption of the various appliances in my house. But the truth is, ever since I have been monitoring, I have significanlty reduced my consumption, which in turn lowers my bill, and saves me money! Call me crazy, but I do like saving money month after month by taking note of my energy usage and making small changes to reduce it.

I'm grateful to have found this forum, where I can share this information with like minded, energy conscious people!

velotocht said:

Mr. Heat Miser and all:

We had a question on this topic a few days back in another string. At this time, I did some studies on my stove. I have reposted my findings from that thread below. Take care.

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Excellent... Thanks for the info on your study Ron!

velotocht said:

Winslow2010 said:

turbotech said:

How can that stove run on 1.16 amps and only use 80 watts? volts*amps=watts, and that stove should be running on 120vac. One of the measurements are wrong or there is a large PF causing the watts to be low.

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It is running at 1.1 to 1.6 amps. The watts on the screen show 80-100 watts so that may be misleading or incorrect. The VA does jump all over in the 150-220 range. I am running the stove on 2/5 since the temps are fairly mild right now.

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Turbo tech:

Good point - and good catch here. I did not do the power calculation (P=V x I x cos theta) - hence missed the fact that 1.16 amps times 120V is more that 80 watts (139 Volt-Amps to be exact, or 139 watts at a pf=1). With 3 inductive motors making up the bulk of the electric load in a pellet stove, a low pf is not really that surprising.

From this conversation, I agree with you, the 'Kil-a-watt' power monitor must be providing 'real power' consummed - not Volt-Amps (complex power). To be able to measure the load power factor and display in true watts is quite impressive for these basic power measurement boxes. And, if the Kil-a-watt is correct, the 80 watts real power consummed at 1.16 amps is still very good -- althought the powerfactor of 0.6 (=80W / 132 VAs) would not make the electric company very happy. But, as a residential customer, who cares? Most residential customers pay for real power consummed, not complex power capacity.

Unfortunately, in the spread sheet I posted above, I also did not consider the true power factor of my pellet stove. My calculations are based on a complex power calculation which I treated as real power - and therefore assume a pf=1. This is highly unlikely as, like most, my stove's electric consumption is predominently due to the electric motors. This makes my spread sheet kind-of wrong. :-(

The good news from my mistake in my spread sheet is that the real power consummed by my stove (the stuff I pay for) will be lower than I have calculated above by maybe 20 or 30%! That's good, right? Unfortunately, I don't have a power meter - only a digital multimeter - so I can't correct and redo my calcuation.

Take care.

RonB

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The Kill A Watt 4460 EZ Meter measures both Real Power (Watts) and Apparent Power (Volt Amps) and even does the division for you to display the Power Factor of the device being monitored. (Power Factor = Real Power / Apparent Power). If you look at my original post at the top of this thread all of those readings came directly from the Kill A Watt Meters display.