New Englanders like myself are used to having some of the highest electricity rates in the continental United States. The Energy Information Administration is predicting that electricity prices in the region could spike a further 16% this summer compared to last as the war in Ukraine continues to affect global fuel prices, including natural gas.
I recently got an email blast from my electric utility company advising several ways in which households can save on their electricity bills. One of the tips was to unplug devices that we are not actively using. These devices, the email claimed, were energy vampires — appliances that continue to use power even when they are turned off or in standby mode — and they could be responsible for a decent portion of our electricity bill.
Curious, I started doing a bit of research. The Berkeley Lab claims that standby power accounts for 10% of American residential electricity use. The National Resources Defense Council claimed that inactive devices represented a whopping 23% of electricity usage in the northern Californian homes that they studied in 2015, which would add hundreds of dollars to the annual electricity bill of the typical household.
Our electricity bill is usually not too offensive for our apartment; our most recent monthly bill was for $78.36, but the weather was pretty temperate for May. Based on our historical usage trends, I expect this to push to over $120 as the AC needs to work harder heading into the hotter portions of summer at the same time as those predicted electricity price spikes hit our area.
If the cited figures were correct, I could stand to save $12–$27 per month off my summer electricity bills by slaying (unplugging) our energy vampires. Were these monsters any more real than the ones in children’s stories? I set out to get to the bottom of it.
The weapon of choice for energy vampire hunters: an electricity usage monitor
The only way to know for sure how much electricity various devices in your home are using is to measure what they are pulling from the wall. An electricity usage monitor can collect this information by serving as an intermediary between your device and the outlet. I got one which can display both instantaneous wattage, as well as monitor the total kilowatt-hours that a device has consumed over time.
The meter that I bought is the Poniie P1500. I spent $16.99 on it, reasoning that the information that I gain from the meter should more than pay for the cost of it. I tested the rough accuracy of the P1500 by plugging it into my lamp which has a 23 W bulb and it measured 24.2 W, indicating that the meter is at least reasonably accurate and potentially highly accurate depending on the manufacturing tolerances of that bulb. If you’d like to pick up your own electricity monitor, you can use the referral link below to support my blog at the same time!
Side note, I did try another slightly cheaper product, the SwitchBot Plug Mini, which has a smaller form factor, smart plug features, and claims to be able to monitor electricity consumption. My testing found it laughably inaccurate, for example it said my 23 W bulb was using only 6.5 W, and that my desktop gaming computer was pulling only 50 W at maximum load when the CPU and GPU are rated for a combined TDP of around 300 W. I returned the SwitchBot Plug Mini and I would especially not recommend that product in particular.
The search for culprits begins
Once I received my electricity usage monitor I began measuring various devices around the house in three main states: active use, standby/sleep, or powered off. This obviously isn’t everything in my house, just a sample of 10 items. I collected the data in a spreadsheet.
By far the biggest energy vampire that I found was our Vizio 55″ smart TV. In what we thought was “off,” this TV was using 15.3 watts around the clock. Apparently the default power setting for this TV was “Quick Start” which puts it into more of a standby mode when you press the power button so the TV can boot up a few seconds quicker. I tried the “Eco” setting and the TV’s vampire draw dropped to 0.55 Watts, over a 25x reduction.
An interesting finding was that most devices, even when fully powered down but left plugged in use about half a watt. Does this add up over time? We’ll find out!
Calculating the cost of my electricity use
On my electric bill I have a supply charge of about 10 cents per kWh for electricity, and then I have several different delivery charges per kWh (which amusingly, add up to cost more than the supplied electricity). The easiest way to determine your cost per kWh is to just divide the total cost of your bill by the total electricity consumption. So I have my $78.36 bill divided by 306 kWh, which leads to a cost of 25.6 cents per kWh.
If you need to know how to convert your device usage into kWh, it’s pretty simple. Start by multiplying the watts consumed by the device by how long it’s running for. For example, a 100 watt device running for 5 hours would consume 500 watt-hours. Then divide by 1000 to get kilowatt-hours, in this case 0.5 kWh.
You can then just multiply the kWh total by your electricity cost. The above theoretical 100 watt device would cost me 12.8 cents to run for 5 hours.
Savings from tackling my biggest 3 energy vampires
First, I was able to save 14.75 watts by changing the power settings on our TV. Since this item is plugged in 24 hours per day, this amounted to a savings of 10.62 kWh over 30 days, or $2.72 per month at my electricity rates.
Second, I started shutting down my work laptop at the end of the day rather than just closing the lid and letting it go into sleep mode. This saves 6.6 watts during the 128 hours per week that I am not working, reducing my electricity consumption by 3.62 kWh, or 90 cents per month. Note that if your laptop has a spinning hard disk, the time spent waiting for it to boot up may not be worth the minor savings here. Since mine has an SSD, the difference between waking from sleep versus a cold boot is only a few seconds.
Finally, this exercise made me more conscious of whether I am actively using items which are on. For example, I have dual monitors on my desktop computer, but I rarely put anything on the second monitor because my primary monitor is large enough for two side-by-side windows. Whenever I am using my computer, that second monitor is sitting there consuming an extra 24.1 watts to mostly just display my desktop background. While this is not exactly an energy vampire, I’m going to include it because without buying the electricity monitor and doing this exercise I would have just left it running all the time. For 6 hours of use per day, that’s 4.34 kWh over 30 days, or $1.08 per month.
Fun tip on Windows: Win+P allows you to easily switch between a single monitor display and extending to multiple monitors, so you can just leave a second monitor in standby and have it quickly turn on only when you need it.
So my total estimated savings just from tackling my biggest three electricity wastes is $4.70 per month, or $56.40 per year. The electricity monitor will have paid for itself after just four months.
Are the smaller energy vampires even worth tackling?
Most of my devices used only around 0.5 watts when off, but this is being consumed 24 hours per day, 365 days per year. Honestly, most devices were far more efficient when off than I expected them to be. It’s worth noting that essentially every device in my apartment is modern, made within the last decade. It seems to me that most manufacturers are pretty good at keeping vampire power draw under a single watt. This may be due to the One Watt Initiative which has led to regulations mandating maximum standby power use in several countries around the world.
To determine if these smaller energy vampires are worth tackling, we need to calculate what a constant 0.5 watt electricity draw costs. Running for 24 hours a day for 30 days, this would use 0.36 kWh. At my electricity rate of 25.6 cents per kWh, a 0.5 watt energy vampire running for an entire year straight would cost $1.12.
To me these smaller energy vampire devices seem to be the point where it’s not worth taking action. Am I really going to bend under my desk to unplug my computer when I’m done using it to save 9 cents per month? Absolutely not. I just counted 20 things plugged in around my entire apartment, and obsessively running around unplugging things when we’re done using them isn’t worth the effort to save 20 bucks per year.
Overall, I would recommend getting an electricity usage monitor like the PN1500 simply for checking if any of your devices are energy vampires like my TV was. Electricity usage per device is otherwise invisible, and it’s likely the monitor will at least pay for itself while also providing some confidence that your electricity bill is as low as you can reasonably get it without inconveniencing yourself.
There’s probably a lot of easier ways I could have saved 5 bucks a month, but as a data nerd I found this exercise enjoyable for its own sake. Happy hunting!