I’ve been thinking about energy usage in the kitchen and how to reduce the cost of using kitchen appliances. 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 these 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 reduce the cost of using them.
What’s the Scoop on the Cost of Using Kitchen Appliances?
I spent way 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. Could the cost of using kitchen appliances be more than it’s worth? 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:
- I am glad I have a gas stove vs. an electric (I think),
- I don’t need to worry about my broth costing too much, and…
- Set a timer when I start researching stuff on the Internet 🙁
Reducing Our Energy Usage
As stewards of creation, conserving energy is one way to treat our Earth with care. (This also translates into lower bills, which stewards our budget at the same time, of course.) In the kitchen, the stove is a major energy drainer. Did you know that 26% of the energy used on “food” in America is used by the average person for home food preparation? (from The Way we Eat by Peter Singer and Jim Mason) When I read this statistic, I was quite shocked, considering the food industry and its processing plants, transportation costs, and grocery store utilities, not to mention restaurants and cafeterias. (Processing takes 29% and transport is only 11%, a challenge to “locavores” who believe eating locally saves money…) I didn’t think that many people even cooked at home anymore!
It strikes me as important, then, that we home cooks conserve energy as much as we can when we’re working in the kitchen. I canned some food(link no longer available) for the first time this week, and I was appalled at the amount of water it took to first fill the jars with hot water to prep them and then fill the canning pot until the water was an inch over the tops of the jars. Seriously. I only made 5 jars of applesauce, but I bet I used 10 gallons of water. I let it cool and poured it on my garden the next day, but I’m still not happy about it!
The True Cost of Using Kitchen Appliances
Here are some stats for you to chew on as you continue to be aware of energy in your kitchen:
I 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 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!).
Know Your Kitchen’s Energy Usage
Here 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
How to Determine the Cost of Using Kitchen Appliances
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? Read this dishwashing mission and learn to reduce energy consumption in your kitchen!
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The thing you are missing is what season you are in, and whether your house needs heat or not at the time you are cooking.
If it’s winter, then all that heat goes into your house anyway, and you use less natural gas to heat. Sure there are some small differences in efficiency between your stove and furnace, but that’s mostly second order effects.
So just align your cooking and baking to when your house needs the heat, and you can basically not worry about the cost.
I’m a natural gas trader, noway your natural gas 88 cents a record low ob historical record in this world, and nation! Considering ng is up 70% from last winter, it only cost 60 a therm, including all 5 ng charges, storage, pipeline, taxes, resource! Ur misleading ur readers, it is very wrong of you to do so!
Glad I found your site! I am starting a project where I will take an existing recipe and calculate the total energy used to make it on my gas range vs. an induction hob. It will be straightforward to calculate the induction version by plugging in a Kill-a-Watt meter between the hob and wall socket. A bit harder to calculate the gas therms used since a recipe can require varying heat levels (i.e. high heat for browning meat, then low for simmer over longer time). Guess I will have to keep track of the time at each heat level with gas. Do you have any ideas or suggestions on how to do this more easily?
Hi Claire! What an interesting project!
I don’t know of any more specific ways to calculate gas energy usage than what you suggested, no. Good luck with the project!
🙂 Katie
Great information. I’m wondering if instapots are a moneysaver
Hi Mary! Yes they can save you money. They’re low on energy consumption compared to other cooking appliances. If it helps you get a homemade dinner on the table more frequently instead of relying on take-out or convenience foods it reduces food costs, but of course, how much that would save any given family is dependent on their current food choices and lifestyle. You can look it up on google and find more ways!
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!
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!
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
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
Thanks, yes, that’s how I got to this post I guess. Thanks for all of the wonderful info, I love your site!
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 ..
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
This really makes you think. I wonder what my cost of use is really adding up to.
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.
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…
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!