Updated on 08.15.11

Saving Pennies or Dollars? Unplugging the Microwave

Trent Hamm

saving pennies or dollarsSaving Pennies or Dollars is a new semi-regular series on The Simple Dollar, inspired by a great discussion on The Simple Dollar’s Facebook page concerning frugal tactics that might not really save that much money. I’m going to take some of the scenarios described by the readers there and try to break down the numbers to see if the savings is really worth the time invested.

Shelley said, “My husband insists on unplugging the microwave. Obviously this saves money but I feel like we are talking about pennies.”

When you’re discussing unplugging a device like a microwave (or a television or a VCR or other such items), you’re trying to avoid the device’s use of standby power. Standby power is a small but constant use of energy that does impact your electrical use for the month.

What’s standby power? Standby power is what powers the clock on your VCR or microwave or the “not currently in use” lights on your television or computer monitor. Those things stay on when you’re not using the device and thus require a tiny amount of power (compared to normal use of the item) all the time.

The Lawrence Berkeley National Laboratory has a very nice table showing the standby power usage of a lot of different types of devices. They vary widely.

Now, if you’ve looked up the usage of a device and want to know what it’s costing you, you’ll need the number from the first column in that table – the average consumption in watts.

In the case of a microwave in standby mode with the door closed, that’s 3.08 watts. 3.08 watts is the same as 0.00308 kilowatts.

Electric companies charge customers in the form of kilowatt-hours, which basically means if you use a device that consumes a kilowatt of energy for an hour, you’re charged whatever their kilowatt-hour energy rate is. The nationwide average hovers around $0.11 per kilowatt hour.

So, how much is Shelley’s microwave costing her per month to sit there plugged in in standby mode?

There are 24 hours in a day and 30 days in an average month, giving us 720 hours. Multiply that by the 0.00308 kilowatts her microwave is using and you get 2.22 kilowatt-hours per month. At a rate of $0.11 per kilowatt hour, the microwave is eating about $0.24 per month sitting there on standby mode.

This brings us bach to Shelley’s question about plugging and unplugging the microwave. In my opinion, if you’re a heavy microwave user, plugging and unplugging the device every day probably isn’t worth the quarter per month. In our home, the plugin for the microwave is actually behind a large shelf of cookbooks, meaning it would be a hassle to plug in and unplug the microwave. I certainly wouldn’t do that a few times a week to save a quarter per month.

If you rarely use the microwave – say, once a month or so – the quarter might very well be worth it. This is also true if the plugin area is really convenient for you or if it’s hooked to a switch so all you have to do is flick a convenient switch with your finger.

For me, though, the only time I might consider unplugging the microwave is if I were traveling for several days. In fact, I did unplug our microwave prior to our recent trip to Seattle, which saved us about ten cents or so.

Unplugging the microwave to save money on the standby energy use saves pennies, not dollars, and is probably not worth the additional effort unless the plug-in is very convenient.

Loading Disqus Comments ...
Loading Facebook Comments ...
  1. Bill says:

    One other advantage to unplugging something is that you help protect it from surges and or brown outs. I’ve had friends lose small appliances like coffee makers or microwaves because of the damage done by voltage issues. It certainly saves if the item lasts longer and doesn’t need replacement.

  2. valleycat1 says:

    If you only use a microwave once a month or so, the better choice is to live without one. We didn’t replace ours when it died 10 years ago (we only used it in the mornings to heat our water for tea, & the occasional food reheating) and haven’t ever missed it. We didn’t notice any change either direction in our electric bill, either.

    Cutting the power to our tv/cable box wipes out the program listing, which takes forever to regenerate itself, so it’s not worth the hassle.

  3. Tanya says:

    I like having the clocks available on my VCR and microwave. It’s worth a quarter to me to have that clock handy in the kitchen!

  4. Mister E says:

    I have my microwave unplugged only because I’ve never really figured out what good they are, I got is as a hand me down many years ago.

    I do keep my coffee maker plugged in because I couldn’t be bothered to fuss with the plug every day for a few cents.

  5. Jonathan says:

    “Unplugging the microwave to save money on the standby energy use saves pennies, not dollars, and is probably not worth the additional effort unless the plug-in is very convenient.”

    Or if the purpose for doing so is to conserve energy, not save money. Although I realize TSD is about saving money, so environmental benefits aren’t usually listed as a reason to do something.

  6. Nick says:

    For me this would be a total waste of time. The microwave that came with my apartment is the most poorly programmed microwave in existence. When it’s plugged in for the first time you are REQUIRED to enter the full time (with am/pm), day, month, and year, BEFORE you can use it to actually microwave anything. Why the hell does my microwave need to know the full day, month, and year?

    Needless to say, it takes at least 30 seconds to a minute to enter all this information, and having to do so every time we have a thunderstorm or blow a fuse is bad enough, let alone if I had to each time I just wanted to use the thing.

  7. moom says:

    If I travel for more than a few days I turn off all the electricity at the fuse box/panel apart from the circuit the fridge is on if the freezer has stuff in it.

  8. Greg says:

    It’s best to think about standby power consumption before buying electrical equipment, not afterwards. If you buy a cheap microwave oven without a clock and without any standby power consumption, you save a quarter every month, and do not have to worry about unplugging.

  9. Lo says:

    In my language there is a saying “Save the small ones, the larger ones will save themselves” meaning save cents and the dollars will be saved too. For me it is also the environmental impact of this move. It is calculated that in Italy, with a population of 60 million roughly, three atomic power plants are required ONLY to keep the red light on(red light being the stand by light on most appliances). On my book that fact alone is more than enough to try and keep those lights off.

  10. Charles Cohn says:

    The economics of unplugging depends on the season. In the winter, the “wasted” energy helps heat the house and replaces some of the energy that would otherwise go into the furnace, so there is no extra cost for leaving things on and unplugging has no benefit. In summer, on the other hand, the wasted energy has to be removed by the air conditioning, so in this case it costs double.

  11. BIGSeth says:

    Simply have one less something (beer, dessert, new hat, taxi ride) per month and a lot of these issues go out the window.

  12. carlos says:

    You should buy a Kill-a-watt. In some states that have energy audit programs, they will actually give you this device. It plugs into the outlet and then your appliance plugs into the Kill-a-watt. It then monitors electricity use. You can use it to measure the standby power electricity use. Very handy indeed.

    I worked for a electric power company and spoke at a standby power expo once. Small world. Anyways, older devices tended to use much more on standby mode… modern devices tend to use much less with the goal of less than 1 watt.

    I only completely turn off my flat screen.

    I think if you want to save more, perhaps looking at LED lights or natural lighting is a better way to save.


  13. Tom says:

    Thanks for the link to that data table.

    I keep the coffee machine unplugged, because we aren’t really coffee drinkers (maybe we brew 2 pots a month). The clock on the microwave is worth $0.24 a month to me

  14. Money Beagle says:

    The microwave is out of the question as ours is mounted above the stove. I don’t think the $0.24 would make it worth it, plus it’s the main clock we use in the kitchen so you could argue that the ‘value added’ from that $0.24 is worth it in having a reliable time telling tool.

  15. Brian Carr says:

    I know it’s minor, but not only are you saving money but you’re not wasting energy that is likely produced by burning coal or some other environmentally unfriendly method. When looking at these things you shouldn’t base your decision solely on dollars and cents.

  16. slccom says:

    Keep anything with a thermostat unplugged. Coffee pots are particularly likely to cause fires. Toaster ovens, toasters, coffee or tea pots, anything with a thermostat in it can overheat.

    Also, saving appliances from power surges is another good reason.

  17. Kathy F says:

    My microwave is built-in above the stove and surrounded by cabinets above and on both sides. I can’t even get to where it plugs in or maybe the contractor who installed has it wired up without a plug. I do have a circuit breaker solely for the microwave that I could turn off. However, my microwave won’t work unless you set its digital clock. I have to do this when the power goes out occasionally, and it is a nuisance.

    But I do have a Smart Strip power strip installed on my TV and DVD player setup so that when I turn the TV off, the DVD player goes off (I mean really off). The DVD player does not even have an on/off switch. If it is plugged into a normal outlet, it is on standby showing clock time. I don’t use it for programming just to watch DVDs.

    I also use a Smart Strip outlet for my computer, monitor, printer, modem and computer speakers. When I shutdown the computer, every thing else get turned off automatically and has no power connected to the devices.

    Smart Strips cost about $35, available from Amazon

Leave a Reply

Your email address will not be published. Required fields are marked *