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# "Going Down" Power

harvesting Energy(=mgh) on stairs
 (+5, -3) [vote for, against]

Lots of time, we walk down stairs. We're wasting all that potential energy. What a shame. So, here's the invention:

Above you are some handles dangling from cables. You grab a handle and hold on while you go down the stairs. You can nearly "float" down the stairs as there'll be less weight on your feet. Easy on the joints too.

These cables are each hanging from a belt that is above you in the stairway.

At the top of the stairs, overhead, there is a heavy drum mounted on a horizontal axis. The belt is geared to the drum, and provides the rotation that you harvest as electrical energy with a generator.

The catch is that the cables need to be attached in a specific way using friction, not fasteners, so that they can "slip" on the belt a bit to accomodate that each person going down may want to go at a different rate. The many cables are each frictionally tugging in different ways, but all "down" to get the belt to move. (I wish I could draw this...).

When you get to the bottom, you let go, and the cable & handle just go over the top of the belt to return to the top.

The ideal place for this is public areas that get a lot of traffic, especially schools & malls that have lots of teenagers who might enjoy running up, and hanging/flying down.

 — sophocles, Jan 15 2005

 I had an idea once of harnessing the same energy.

 Mine involved stairs that depressed when stepped on, driving a gear attached to a chain, and that chain is common amongst all the stairs.

 The first step would start the chain, and each step afater would accellerate it, as the gearing would increase on each stair as you descend.

I had another idea of a layer of pizioelectric crystals beneath the floor, discharging energy with every step.
 — Giblet, Jan 15 2005

The energy here is miniscule - 2.5m*60kg*10 = 1.5kj
That's 100w light bulb for 15 seconds. In high trafic areas, that might add up, but safty reasons prevent that.
 — my-nep, Jan 15 2005

Why stairs? If the cables dropped you down a vertical shaft, you'd make some architect's life simpler.
 — tiromancer, Jan 15 2005

A variation: use a beefed up venetian blind mechanism.
On the way down, wind up the spring. On the way up, begin with a sharp tug down and fly up to the top again.
 — Ling, Jan 15 2005

 Available energy = mgh.

Can't do much about g or h. To optimize, we must increase m. Put ice cream and pastry shoppes on the upper floor.
 — SledDog, May 19 2006

Move to a more massive planet?
Design buildings with a greater floor-to-ceiling height?
 — methinksnot, May 19 2006

why don't elevators harness their "going down energy" ?
 — Domser, Aug 30 2008

//why don't elevators harness their "going down energy" ?// To some extent, they do through the use of counterweights. Of course, they could do so more effectively by weighing the passengers and adding or removing counterweight mass as appropriate at each floor. Like changing the weights on a weight bar or gym machine, but automated.
 — spidermother, Sep 02 2008

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