Kitchen Stewardship | A Baby Steps Approach to Balanced Nutrition

Food for Thought: The cost of using your kitchen’s appliances

March 5th, 2009 · 13 Comments · Avoiding Waste

I’ve asked you this week to think about your energy usage in the kitchen.  This includes oven, range-top, microwave, toaster oven, lights (over your sink, your stove, ceiling lights, etc), refrigerator, freezer, dishwasher, garbage disposal and hot water from the tap.  Clearly some of those are going to be bigger energy-drainers than others, but we can be conscious about all of them and cut our use to save the planet and our wallets.

What’s the scoop?

I spent waaaayyyy too many hours submersed in the depths of the Internet this week, googling different phrases to try to find hard facts for this Food for Thought.  I really wanted to know for myself, too, how much it costs to run my oven at 350 degrees or my burner on simmer for one hour, and what kind of energy it takes to run my toaster oven vs. my microwave (since I’m trying to do more of the former and less of the latter).

Why bother?

I make a rockin’ broth that I cook for 24 hours, and I started wondering if I was cutting into my $$ savings by raising my natural gas bill.  I also dehydrated some “crispy nuts” in the oven for 24 hours, and again, wondered if I was paying an arm and a leg for nuts!

What I found taught me three things:

    1. I am glad I have a gas stove vs. an electric (I think),
    2. I don’t need to worry about my broth costing too much, and…
    3. Set a timer when I start researching stuff on the Internet :(

      The Hard Numbers

      Here are some stats for you to chew on as you continue to be aware of energy in your kitchen:

      exclamation_32x32I read that gas ovens are about 1/3 of the expense of an electric oven, BUT when I do the math, they’re coming out much more even.  Perhaps rates have changed since that data was widely disseminated.

      These figures use my gas company’s current rate of 88.733 cents/CCF and my electric rate of 8.5 cents/kWh; you can figure your own using equations I’ll provide below.

      • Microwave (1100 watts)= 9.5 cents/hour
      • Toaster oven (1500 watts)= 12.75 cents/hour
        on highest heat, so 350 degrees would be even less
      • Gas Oven at 350 degrees = somewhere between 10 and 23 cents/hour, depending on which estimations you use!
      • Gas range 9,500 BTU burner (standard size) = 8.6 cents/hour
        I wonder what this translates into for simmer?  I’m guessing 3-5 cents/hour.
      • Dishwasher with gas water heater = 10 cents/load for hot water, plus about 10 cents/hour for electricity, possibly up to 40 cents per load.
      • Electric oven at 350 degrees = 12-19 cents/hour, depending on which figures you use
      • Electric range = 10-16cents/burner/hour
      • Dishwasher with electric water heater = 41 cents/load

      I’m not too worried about my toaster oven or even my range burners, but the dishwasher seems like a place for improvement.  It was number 5 on the “Top 5 Most Costly Appliances” and may be up to 2% of your annual energy consumption in the house, potentially $50 or so a year.  Imagine 25-50 cents per load, depending on the source of your hot water. (Click here for ideas to reduce dishwasher environmental impact.)

      You can find easy energy calculators for electricity and natural gas.  The electric rates are about 1 cent higher than mine, and you’ll have to enter your own natural gas rates (in therms, see below).  You just tell the calculator what items you have in your house and how often you use them, and you’ll get a breakdown of where you spend your energy.  Or just use it to figure out how much a 5-minute shower costs (9 cents just to heat the water at my house.  That means if I cut 5 minutes off my shower every day I can save over $30 a year!  With electric water heaters you could save $100 easily by cutting 5 minutes off!).

      Do It Yourself

      moneyHere are the equations you can use to figure out exactly your own energy consumption costs.

      Information you’ll need to have:

      • BTUs on your gas burners and oven (in the instructions or on a plate on the stove itself — try inside the door or in the pots and pans drawer)
      • Watts for toaster ovens, microwaves (mine were on the backing plate or underside)
      • Watts or kWh for electric ranges
      • Watts (or volts and amps) for the dishwasher (on the info plate) and # of gallons per load (probably in the instruction booklet)
      • Cost/kWh from your electric company
      • Cost/CCF or therm from your gas company

      To calculate electric appliances:

      • If your appliance only lists amps and volts, v x a = watts
      • Watts/1000 = kWh
      • Simply multiply that number by the cost/kWh of your electricity

      My example:

      • Toaster oven is 1500 watts.
      • 1500/1000 = 1.5 x 8.5 cents = 12.75 cents/hour to run the toaster oven

      Gas is trickier…

      • If your company charges in CCFs, multiply your CCF cost by 1.024 to get cost/therm.
      • Cost per hour of gas appliance = BTUs/100,000 x cost/therm

      My example:

      • My rate is 88.733 cents/CCF x 1.024 = 90.86 cents/therm
      • My standard burner is 9,500 BTUs.
      • 9,500/100,000 = .095 x .9086 = 8.6 cents/hour to have the burner on high
      • My oven is 18,000 BTUs.  18,000/100,000 = .18 x .9086 = 16 cents/hour.  I imagine that’s to run the oven at 550 degrees, its personal best.  If percentages apply, and I don’t know if they do, 170/550 is about 30%, so maybe it costs 4.8 cents/hour to dry my crispy nuts.  About a buck.  I guess that’s alright…

      And the combo:  Dishwasher

      Electricity used at my house:

      • 9.6 amps x 120 volts = 1152 watts
      • 1.152 x 8.5 cents = ~ 10 cents/hour x 2-3 hours (short wash) = 20-30 cents electricity.
      • I can’t find how many gallons/load, but it’s between 3-10 according to Energy Star guidelines.  Let’s say 4 gallons (I almost always use “short wash”).
      • If a 5-minute shower at 2.5 gallons/minute is only 9 cents,  that means I’m only using less than 3 cents of hot water.  Wow!

      My dishwasher still costs 23-33 cents per load, which can really add up over the course of a year.

      Now what?

      So now the big question for the dishwasher, if you have one, of course, is:  Which is a more efficient use of energy:  hand-washing dishes or using the dishwasher? Come back Monday for the answer and a dishwashing mission to reduce energy consumption in your kitchen!

      Send me your Meatless Meal Recipes by Sunday at 5:00 p.m.!

      If you missed the last Monday Mission, click here.

      Tags: ··

      13 Comments so far ↓

      • Missy

        Thanks, Katie! I also cook my stocks (at least once a week) for 24 hours on a gas burned and often use my oven to dry out nuts and sprouted grains. I have thought alot about the cost involved, I am happy to know its not costing me much money.
        This past summer I was trying to wean my self from relying on my dishwasher. It wasn’t cleaning well, and I was sure it was consuming way to many resources. Then I read in “Organic Housekeeping” that it was more efficient to run the dishwasher than to hand wash. That was all I needed to hear, and my husband bought me a new dishwasher. As a mother of five, 40-80 cents a day is so worth the time it saves me in the kitchen. Less than a cup of coffee a day, right? Guess I better make sure my husband has a pot of hot coffee ready before he leaves for work. I wonder which is better: a percolator or drip machine . . . . I don’t even want to think about my cappuccino maker!

        [Reply to this comment]

      • Katie

        I was happy to find out that the cost wasn’t huge either. I still think for the crispy nuts, a dehydrator (I just borrowed a friend’s for a few weeks) is probably the way to go. Then you can really cram a lot in there!

        [Reply to this comment]

        Olivia Wasik Reply:

        That’s so funny! I thought the same thing about my broths. I just didn’t have the info to see how much it was costing me. As for my nuts, I use a dehydrator. My oven is old. The oven dial doesn’t go as low as 150.

        [Reply to this comment]

      • Rachel

        I just recently read about the cost of using a dehydrator. I don’t recall the actual numbers but it came out to be about $.05 per hour. Not too bad. I’ve started using a pressure cooker to make bone broths. Now I can get really great broth (with bones falling apart) in 1.5-3 hours instead of 24+ hours simmering away on the stovetop. I know that Sally Fallon doesn’t approve of that “new fangled” contraption but a lot of TFers have looked into it and choose to use one. Make fast work of cooking beans, too.

        [Reply to this comment]

        Katie Reply:

        I did stop using my pressure cooker for beans after reading Sally’s opinion. Interesting to hear another side! I’ve never used it for stock, although I know a lot of people use a slow cooker to reduce energy costs. Hmmmmm…

        [Reply to this comment]

      • Michelle

        This really makes you think. I wonder what my cost of use is really adding up to.

        [Reply to this comment]

      • Shu

        What about a slowcooker? I like to throw in meat and some vegetables in the morning and then come home to a ready stew on weekdays. And I use it to make my bone broths, because really, you never need to watch it!

        But leaving it on for hours and hours is making me worry about the cost ..

        [Reply to this comment]

        Katie Reply:

        Shu,
        You can find the wattage on the appliance and do the math with the links here, but my guess is that it would only cost 5-10 cents per hour. Still cheap for bone broths! :) Katie

        [Reply to this comment]

      • Mendy

        My desire to learn how to make stock coincided with a curiosity about using our woodburning stovetop (not a cookstove, just the heating type) as a cooking tool. From what I’ve learned, most woodburners can also be used at least as a slow-cooker, and ours can even boil (depending on how hot of a fire you build) and fry (especially if you use cast-iron skillets.) I’m beginning to think I’ll be having a stock pot on my stove the rest of the winter. It’s already running, so no extra expense, it doesn’t require much attention and it turns out great!

        [Reply to this comment]

        Katie Reply:

        Mendy,
        I’ve heard of people who do that in their slow cooker, and just keep tossing in veggie ends and bones all the time! Awesome! :) Katie

        [Reply to this comment]

        Katie Reply:

        I just realized this was not on the stock post – have you seen my instructions for increasing the nutrition in homemade chicken stock? http://www.kitchenstewardship.com/2009/03/30/monday-mission-how-to-make-your-own-homemade-chicken-stockbroth/ :) Katie

        [Reply to this comment]

        Mendy Reply:

        Thanks, yes, that’s how I got to this post I guess. Thanks for all of the wonderful info, I love your site!

        [Reply to this comment]

      • Jae

        Thank you katie for all of the research on energy costs.
        Have often wondered about the operating costs of appliances/hot water use for cleanup and if I was really saving on some of the DYI food preparation.
        Am finding your topics and others replies to be so interesting! Love your work!

        [Reply to this comment]

      Leave a Comment

      Welcome!  Meet Katie.

      I embrace butter. I make homemade yogurt. I eat traditional real food – plants and animals that God created, not products of plants where food scientists work. Here at Kitchen Stewardship, I share how I strive to be a good steward of my family's nutrition, the environment, and our budget, all without spending every second in the kitchen. Learn more about the mission of KS here.

      PTE350
      Squooshi reusable food pouches