First, I must say that a search shows me that the general idea of capturing power fron an elevator has already been posted here, I will provide the link to that idea when I figure out how.

This version hopes to recoup a bit of the power thats been used to lift the elevator.

In taller buildings when the transport is near the upper floors, a sensor would detect that and relay a message to the top of the elevator box where there is located a mechanical device that slides four solid strips out very close to the walls of the shaft to nearly close off all air rushing past.

At the top of the shaft is located an intake turbine that will be spun up by the vacuum as the elevator descends. When the elevator is near the lower levels, the strips will retract so not to reverse the process on the way back up.

The power might not be great, but some could be reclaimed, possibly cycled into batteries for emergency lighting systems.

Might make for a smoother ride on the way down and ease the wear and tear of other parts.
-- nth, Dec 18 2006

elevator generators Elevator_20Generators
[nth, Dec 18 2006]

I think you need to keep in mind two things when you consider this.

1) when you close off the flow of air in the shaft you will create a vacuum on the upper side, but you will also create pressure on the downward side. Thus negating your effect.

2) elevators operate with counterweights. With some variation for load there is little gain or loss of potential energy in the elevator system. as the cab gains energy the counterweight loses it. Thus the only power in the system is that used to actually move the car this again limiting the potential for power generation as any power generated through suction will be directly offset by the need for more power to pull up the counterweight(dropping the cab)

I'm not sure on this but I would guess that at about 50% of maximum load that an elevator uses exactly the same amount of power to go up as it does to go down.
-- jhomrighaus, Dec 18 2006



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