How Much Electricity Costs to Power Household Devices & How to Cut Use

“Micromanaging” has a certain negative connotation due to its application in a work environment. When it comes to budgeting, however, micromanagement should be embraced (don’t let anyone tell you otherwise). Any time you are able to not only save yourself some money, but also reduce your negative impact on the planet, that’s a beautiful thing. One of the areas you can do this with is your household electricity consumption.




I decided to do a little experiment around my house with all of my electricity powered devices and share my findings on their electricity usage with you. My main goal was to find out how much electricity I was wasting and cut that down as much as possible.

How Much Does Electricity Cost for Common Household Devices?

For a long time, I have had a pretty general idea of what my electricity bill has been. Outside of July and August, when the cost of air conditioning inflates my bill (muggy Michigan summers), a typical month for me is right around $50.

how much electricity cost

I’ve done a lot of things to keep my electricity cost down, which include:

  • every bulb in the house as a CFL or LED (every bulb you now buy should be LED).
  • I unplug devices I rarely use.
  • I keep lights turned off when I’m not in the room and during daylight hours.
  • I turn my desktop computer, monitor, and printer off when I’m not using them.

But I’ve always thought that I could do more. The problem was that I had no idea how much electricity cost each household device was generating. I had some nagging questions that I wanted answers for:

  1. does it cost anything to leave a phone charger plugged in?
  2. what about a laptop charger?
  3. how much electricity does my desktop computer use in sleep mode vs. awake mode vs. off?
  4. how much electricity does my DVR use in sleep mode vs. awake vs. off?
  5. is my TV sucking up energy when turned off?
  6. which of my appliances are using standby power?

I found answers to all of these questions and a few added surprises…




Electricity Monitoring Device Use

In order to do this test, you will need an electricity monitoring device. There is no getting around that.

Hopefully you can learn from my tests, but your personal devices may vary. In other words, there is little universality in electric use. If you want exact numbers for your situation, you will need to get an electricity monitoring device of your own.

There is one reputable device on the market with great reviews:

P3 International Kill-A-Watt Electricity Usage Monitor: Kill-A-Watt calculates volt, watt, amp, hz, kwh, and expenses per day, week, month, and year.




Electricity Use Per Device Test Results

The following data is the result of my tests. Note that I used $0.15 per kWh for my calculations. Your cost may vary per your utility company.

Also note that there are, in many cases, multiple tests for each device based on how it may be used (i.e. laptop fully charged vs. charging).

Data shown is in the format of: device tested: watts drawn, $ to power per year (@$0.15 per kWh), CO2 emissions per year (in lbs.), and lessons specific to each. I did not test things that I used very randomly and for a specific purpose (e.g. an engaged blender or toaster), rather my goal was to find where electricity was being wasted by keeping things plugged in.

  • CFL bulb lamp, off (40W): 0W, $0.00, 0 lbs. – there is no need to unplug lamps.
  • CFL bulb lamp, on (40W): 41.8W, $54.17, 442 lbs. –  I am surprised even CFLs use this much electricity. Turn your lights off when you don’t need them on.
  • Macbook, charger-only: 0W, $0.00, 0 lbs. – this is not universal on chargers. Gave me a sigh of relief though, b/c I always leave it plugged in.
  • Macbook, charging engaged: 60w, $77.76, 650 lbs.
  • Macbook, charging closed: 44.7W, $57.93, 473 lbs. – not much difference between engaged and closed, when charging.
  • Macbook fully charged, closed: 0W, $0.00, 0 lbs. – good to know that the adapter shuts down when a Mac is fully charged.
  • Macbook fully charged, engaged: 28W, $36.29, 144 lbs. – not as low as expected.
  • Acer laptop, charger-only: 1.1W, $1.43, 11.6 lbs. – it’s not much to keep it plugged in, but it’s still wasteful.
  • Acer laptop, charging engaged: 43W, $55.73, 440 lbs.
  • Acer laptop, charging closed: 17W, $22.03, 190 lbs.
  • Acer laptop, fully charged, engaged: 24W, $31.10, 240 lbs.
  • Samsung smartphone, charger-only: 0W, $0.00, 0 lbs.
  • Samsung smartphone charging: 6W, $7.78, 57 lbs. – this is much cheaper than expected.
  • Samsung smartphone charged: 1.7W, $2.20, 17.2 lbs. – also much cheaper than expected.
  • 0.5W LED nightlight: 0W, $0.00, 0 lbs. – my LED nightlight for my bathroom uses so little electricity, it doesn’t register on the energy monitor.
  • Black & Decker toaster, not engaged: 0W, $0.00, 0 lbs.
  • KitchenAid Blender, not engaged: 1.5W, $1.94, 16.8 lbs. – surprising in that my toaster does not use any energy when plugged in. Will keep unplugged. $1.94/yr. saved.
  • Vizio 42″ LCD TV, off: 0W, $0.00, 0 lbs. – my TV uses so little energy when turned off, it does not register. Surprising, and I’m thankful.
  • Vizio 42″ LCD TV, on: 230W, $298.08, 2425 lbs. – wow, talk about an energy hog.
  • Comcast DVR, on: 32.4W, $41.99, 345 lbs.
  • Comcast DVR, off: 31.2W, $40.44, 330 lbs. – this was the surprise of this test. A Motorola Comcast DVR uses as much energy when turned off as it does on.
  • Sony BluRay, off : 1W, $1.30, 10.7 lbs.
  • Sony BluRay, on: 16W, $20.74, 172 lbs. – I had been leaving this on b/c it is so slow to start up. Not anymore. $20/yr. saved.
  • Super Nintendo, off: 0.7W, $0.91, 7.4 lbs. – awesome that this is the only gaming system listed, no?
  • Super Nintendo, on: 6.6W, $8.55, 71 lbs. – wow, an energy sipper.
  • Printer, off: 2.6W, $3.37, 27.1 lbs. – another surprise. I will be unplugging. $3.37/yr. saved.
  • Printer, on, not in use: 5.9W, $7.65, 63 lbs.
  • Cordless phone base, w/phone: 1.6W, $2.07, 17.2 lbs. – very cheap!
  • Cordless phone base, w/o phone: 0.9W, $1.17, 10.2 lbs. – very cheap!
  • Paper Shredder, plugged in, off: 0W, $0.00, 0 lbs.
  • Acer Desktop Computer, off: 1.7W, $2.20, 18.6 lbs.
  • Acer Desktop computer, on, awake: 45W, $58.32, 475 lbs.
  • Acer desktop computer, on, sleep: 3.3W, $4.28, 35.5 lbs. – I can’t believe how cheap my desktop on while asleep. Only $2 per year vs. off!
  • Acer 20″ LCD monitor, off: 0W, $0.00, 0 lbs.
  • Acer 20″ LCD monitor on, awake: 23.5, $30.46, 250 lbs.
  • Acer 20″ LCD monitor on, sleep: 0W, $0.00, 0 lbs. – just as the TV, a big surprise.
  • Ooma VOIP device, on: 6.6W, $8.55, 70 lbs.
  • Netgear wireless router/modem, on: 7.8W, $10.11, 83.6 lbs.
  • LED Alarm Clock: 1.6W, $2.07, 16.8 lbs. – cheap! Might as well put the phone away unless you want to declutter.
  • Refrigerator, closed (no light) and not running: 0W, $0.00, 0 lbs.
  • Refrigerator, open with light on, not running: 41.7W, $54.75, 442 lbs. – that little light in the fridge is not cheap.
  • Refrigerator, closed (no light), running: 155W, $206.00, 1808 lbs. – this highlights the importance of a good fridge and keeping the fridge door shut.

Here are some general learnings on electricity costs from the above results:

  • No need to unplug lamps, but even CFLs are not cheap to keep on. Turn off the lights when you leave the room! Despite their improvements, light bulbs are still one of the biggest electricity vampires. LEDs are a beautiful thing.
  • Change the setting in your computer to have a 3 or 5 minute sleep mode delay versus 30 minutes or never. This could save you dozens of $’s per year.
  • If you don’t have your DVR set to record shows, unplug it. It could save you $40+ per year vs. just turning it off!
  • Some chargers left plugged in drain energy, but most don’t. If they do, it is not much. Better to not be wasteful though.
  • I was not expecting to find my blender using energy when not in use. You never know which appliances are vampires. Better to test and have definitive answers than always wonder and feel doubt or even guilt.
  • DVRs are never really “off”. My DVR essentially adds another $4 to my cost of cable every month.
  • Perhaps the most important lesson of all: electricity is still incredibly cheap and incredibly polluting. To think that just $1 of electricity costs equates to about 7.5 lbs. of CO2 emissions is disgusting. If there is any hope for this planet, it lies with solar and other renewable energies.

I estimate that the changes I will make from these learnings will save me about $75 per year on electricity costs at the $0.15 kWh price. That’s more than 10% of my entire electric bill. As the cost of electricity increases (and it will) that $ amount will only go up every year. I more than made back my tiny investment in the P3 International Kill-A-Watt Electricity Usage Monitor in just the first year, and after I let all of my friends and family borrow it, I can sell it.

Update: It looks like this one little device ended up saving me 22% per month in electricity costs!

If this topic interests you, check out my entire series on eco-friendly cost savings.

Electricity Cost Discussion:

  • Which of these findings surprise you?
  • How much is your monthly electricity bill, on average?
  • Have you run an experiment like this? What were your findings?

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