Food for Thought: The Cost of Using Your Kitchen Appliances

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:

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 🙁

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 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!