While visiting Notre Dame this week I encountered bathrooms that had gone green. That is, they had signs that instructed me (while still giving me the option) that using an electric hand dryer was environmentally positive, while using paper towels was environmentally insensitive. Why, I wondered, was something that required electricity more eco-friendly than a piece of paper that could be recycled? Confused, I wiped my hands on my pants. Later, I received a little help for my dilemma and embarrassment from an article at Slate:
Calculating the impact of electric dryers is easy enough. A fair amount of energy goes into manufacturing metal goods with mechanical parts. But the fact that dryers last so long—typically between seven and 10 years—means that production accounts for a negligible part of the hardware’s total energy consumption. The vast majority of a dryer’s environmental toll stems from the electricity it requires; a typical warm-air dryer uses around 2,200 watts of power when switched on, plus about 2 watts while in standby mode. If you dry your hands for 30 seconds (as opposed to the 43 seconds required to get them fully water-free), then you’re using about 0.018 kilowatt-hours of electricity. Do that three times a day for a year, and your insistence on dry-hand decorum has run you 19.71 kWh of electricity, which translates into roughly 26.61 pounds of carbon dioxide emissions.
There are several variables that can complicate the hand-dryer equation. The first is the emergence of a new generation of dryers, such as the XLerator and the Dyson Airblade, that claim to be at least 80 percent more efficient than their forerunners (due in part to much shorter drying times). You also need to consider how your local power grid generates its electricity—the more coal that is used, the more carbon a dryer will generate per kilowatt-hour. (As always, you can check out your grid’s fuel mix by using the Environmental Protection Agency’s Power Profiler tool.)
These complications, however, pale in comparison with those that bedevil the life-cycle assessment of paper towels. The main problem here is that there’s so much variation in how rolls are produced, starting with how the trees are harvested. The vast majority of American paper towels begin life in well-managed commercial timberlands, where trees are replaced after harvest, so deforestation isn’t a pressing issue. But one must account for the fossil fuels expended on machinery and log transport. Then there is the energy-intensiveness of the pulping process, which can result in the emission of harmful pollutants into nearby waterways. One must also consider the cost of trucking the towels from manufacturer to client, a data point that will vary widely according to the restroom’s distance from the paper mill. (Yes, dryers must be transported in this manner, too, but far less frequently, given how long each one lasts.)
The problem here is the experience of anyone who uses public restroom — the technology of hand-washing and hand-drying never abides for more than 18 months. I have long wondered, after seeing soap dispensers and paper towel holders and electric dryers come and go, how often the salesmen for these items visit bar and restaurant owners to push a new line of advanced products. We have long had a crisis in hand-drying and no one, not even the neo-Calvinists, seem to care!
Maybe the best option is for all of us to imitate professional golfers and carry around our own personal hand towel.