The Surprising Energy Consumption of Glade Plug-Ins

glade%20plugins.gifSC Johnson has been heavily advertising their Glade Plug-Ins products recently and it got me to thinking, “How much electricity do all those Plug-Ins use?”. The answer: a surprisingly large amount - hundreds of thousands of barrels of oil worth, in fact.

To try and estimate the number of Glade Plug-Ins I used two numbers (since the company doesn’t provide exact sales figures). On the SC Johnson website they state that hundreds of millions have been sold over the course of more than 15 years, which if we take a fairly minimal case of 300 million over 15 years that gives us a number of 20 million per year. (This assumes they sell the same number today as they did when first introduced, which is obviously not true, so in fact the current sales rate is going to be considerably higher. But we’ll take the average for now.)

A second number comes from a recall notice in which 2.5 million of one particular model manufactured in a 4 month period in 2002 were recalled. This gives a total of 7.5 million per year, for that one model. Assuming a modest growth of 5% year over year (and my guess is the category has been growing considerably faster), that gives 9.5 million units in 2007. Since this was the least expensive of three Plug-Ins models, let’s say it comprises about half their total sales. This also gives us a 20 million per year number.

That’s a nice round number to work with, and probably on the conservative side, but my interest here is more in doing a thought experiment about how small individual actions add up to larger consequences, rather than getting a precise number on the amount of electricity. So 20 million is a good place to start. (It also doesn’t include similar products from other companies.)

The basic Glade Plug-in uses 2.1 watts of energy. The fancier ones with nightlights and light shows use over 3.5w. Let’s use 2.5 watts as our average across all the units sold, not knowing exactly how the model breakdown occurs so we’re again assuming that the lower-wattage/less expensive units make up 50% or so of sales. And the units may not draw their full power all the time (e.g. the nightlight is not on all the time).

Total electricity consumption then is:

  • 20 million units x 2.5w x 24 hours x 365 days / 1000 = 438,000,000 kWh (kilowatt hours, the standard measurement in the US for power consumption over time)
  • To power a year’s worth of Glade Plug-Ins therefore requires almost 26 million gallons of oil, or 613,000 barrels (one gallon of oil produces 17kWh of electricity, there are 42 US gallons in a barrel, so 714kWh per barrel)
  • It also equates to 1/8 the output of a typical 500 megawatt coal-fired power plant. In the course of producing this much energy, the power plant will also create 1250 tons of sulfer dioxide (causes acid rain) and almost half a million tons of carbon dioxide (causes global warming).

(I’m not counting the amount of energy and resources required to produce the Plug-Ins in the first place, which is almost certainly more than what they consume.)

Not to mention that Glade Plug-ins were recently found by the National Resources Defense Council to contain “moderate” amounts of Phthalates, and one specifically in air fresheners which interferes with hormone production in humans and is listed by the State of California as causing birth defects or reproductive harm.

So that seems like quite a lot of resources to burn for something as relatively frivolous as giving your house a strong smell of Apple Cinnamon or Suddenly Spring. A better solution might be something like these Aroma Sticks from Method which require no electricity and are not fabricated using plastics and are also phthalate and butane free.

PS, If someone from SC Johnson or elsewhere is able to provide more precise sales and energy usage numbers, I’ll be happy to update.