Don’t buy power bars to save money

A tweet from @TorontoHydro was retweeted into my timeline about the use of a power bar with a timer to fight phantom power, with the idea being to avoid wasting electricity and by extension, to save you money.

But it’s a false economy.

Toronto Hydro Power Bar Coupon

The power bar shown in the ad is a “Westek TE08WHB Indoor 8-Outlet Weekly Digital Power Strip Timer” that you can buy from for $33.63 including taxes and shipping. As far as I can tell, you can’t use these coupons with Amazon. You’d have to find a similarly priced device in an electronics store, but they often carry more expensive devices.

I purchased a wattmeter and have measured the energy consumption of almost every device in my home. The kinds of devices usually plugged into power bars near your computer are printers, disks, phone chargers, etc. The phantom power usage of these devices are on the order of a few watts. Those dinky phone chargers are often less than one watt and don’t even register on my wattmeter when they’re not charging.

Using my energy consumption taking into account peak, mid-peak, and off-peak prices over 24-hours averaged for 2016 the rate is 17.8¢/kWh from Hydro Ottawa. However, most likely you’ll have the strip turned off mainly during off-peak times overnight, so let’s assume the rate is more like 15¢/kWh.

Let’s do the calculation. Feel free to substitute your own numbers that reflect your environment. How many kWh of savings will it take to pay off the purchase price?

$33.63 / $0.15 per kWh = 224 kWh

Let’s say you have enough devices plugged into this strip so that it uses 10 W of phantom power. Now let’s say you have this strip off 16 hours a day. In one day you’re saving:

10 W * 16 h / 1000 W per kW = 0.16 kWh per day

224 kWh / 0.16 kWh per day = 1,400 days, or 3.8 years

That’s just an OK payback time. If you’re using 10 W. Are there better ways to save money and energy?

My large stove burner uses 2.7 kW. It took 30 seconds to get a reading on my energy monitor while I ran this test. I used up:

2700 W * 30 seconds = 81,000 Ws

This is the equivalent of leaving that 10 W power strip turned off for 8,100 seconds, or 2 hours & 15 minutes.

So you can see that making minor adjustments to high energy consuming appliances will swamp any savings you can make by purchasing a power bar with a timer. Don’t leave a stove burner on for even a few seconds more than necessary. Turn down your electric water heater a couple of degrees. Run your electric dryer for less time or less dry. Don’t leave lights on when you’re not in a room. Switch to LED lighting for any bulb on for long periods of time, like yard lights.

Have you noticed that I haven’t even talked about the environmental cost of manufacturing, shipping, and eventually recycling that power bar? That’s too hard to calculate but ask yourself if you really think you’ll be putting less CO2 into the air to offset the CO2 expelled to get it to you and get rid of it later.

I use a UPS on my 55″ LED TV as a master to switch off my sub-woofer which uses an absurd 20 W in standby. But I’m really using the UPS for lightning protection of my TV, receiver, Apple TV, and DVR. Switching off the sub-woofer is a bonus savings that doesn’t cost me any extra.

I’m not saying you shouldn’t buy a power bar, but don’t kid yourself that plugging your phone charger into this is going to save money or the environment. You have to have much higher wattage devices plugged in.

Buying one of these power bars should be one of the last things you do to save money after you’ve done all the other things—and more—I mentioned above.

Author: Tom

Destroyer of software. If I haven't tested it, it hasn't been tested.

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