I've been trapped in passcard protected stairwells, and for a few heart-pounding minutes in a slow elevator, but I've never been betrayed by an escalator... for obvious reasons.
Photo Credit: A-Digit/istockphoto
I like riding the escalator. I like watching the steps fold flat and feeling the wind in my hair. Besides, nothing beats an escalator for visibility. Elevators are hidden behind doors, and stairs tucked away within fireproof stairwells. But the escalator? It's a different animal. People build around the escalator. It's the centerpiece of the mall, visible from a distance.
But when it comes to energy use, the escalator is shamefully bad.
A case study from one environmentally-minded motor control manufacturer--The Power Efficiency Corporation--suggested that an escalator operates at a rate of about four to six kilowatts. Multiply that by every hour of every day that the escalators run and you've quite a sum.
From what I can see, the biggest trouble is that escalators don't care if you take the stairs. Unlike elevators, which only come when they're called, escalators run constantly.
Elevators are better, but the characteristics that make them more efficient, like on-demand service to varying heights, also make it difficult to generalize about the energy use. So I cheated and set a rule of thumb according to what I can reasonably expect of myself. I'll take the stairs to the sixth floor (where I work) but the elevator to my friend's apartment (on the tenth floor of his building).
Recent efforts to create variable-speed escalators and efficient elevators that use regenerative breaking give me hope that one day soon I'll get to be guilt-free and lazy again. Until then, I'll work on my calf muscles.
Edit: I messed up on the kilowatt, kilowatt-hour notation up above. Fixed now. Thanks to
But when it comes to energy use, the escalator is shamefully bad.
A case study from one environmentally-minded motor control manufacturer--The Power Efficiency Corporation--suggested that an escalator operates at a rate of about four to six kilowatts. Multiply that by every hour of every day that the escalators run and you've quite a sum.
From what I can see, the biggest trouble is that escalators don't care if you take the stairs. Unlike elevators, which only come when they're called, escalators run constantly.
Elevators are better, but the characteristics that make them more efficient, like on-demand service to varying heights, also make it difficult to generalize about the energy use. So I cheated and set a rule of thumb according to what I can reasonably expect of myself. I'll take the stairs to the sixth floor (where I work) but the elevator to my friend's apartment (on the tenth floor of his building).
Recent efforts to create variable-speed escalators and efficient elevators that use regenerative breaking give me hope that one day soon I'll get to be guilt-free and lazy again. Until then, I'll work on my calf muscles.
Edit: I messed up on the kilowatt, kilowatt-hour notation up above. Fixed now. Thanks to
Great entries commenting on our daily activities. Very enjoyable to read and informative.
But be careful when reporting energy use--kilowatts are already a measure of energy per time (i.e. power); saying kilowatts per hour doesn't make much sense. Maybe you mean: "escalators consume energy at a rate of four to six kilowatts," which is about the same as running four to six hairdryers simultaneously.
qovert, Thanks for the correction! That's something I tried to avoid, but I slipped up here. I've fixed it in the entry and noted the edit.
In Munich they have transit escalators which don't run at all until someone approaches, some of which can move either direction, and which have red or green lights to indicate whether you can get on and use them going that direction or not.
This problem has already been solved. I wonder why the New York transit authority didn't know about the German examples, which virtually always worked in my experience.
It's great to finally see people making more energy conscious decisions about building. Elevators and escalators are just one component of the entire "green building" initiative and considering the energy need to maintain something this massive is very high. Up until the past few years this has largely been overlooked.