Algodoo

If each step were attached to a rack that rotates a pinion on a generator shaft, you could produce electric power whenever people walked up or down the stairs. With that idea in place, parents would encourage children to run up and down stairs instead of frustratingly yelling at them to STOP IT!

At first I thought that the stairs should work like the toggle button on top of a pen where each stair could click down on the way down and store the energy in a spring and then click up when the person goes up stairs returning the spring energy to help them up the stairs. I couldn't think of a simple way of doing that. Another approach (based on your comment) would be to make a motor/generator and connect it to a battery where the motor/generator acts like a generator when someone is going down stairs and acts as a motor when someone is going up stairs.

I think those ideas (yours and mine) work in theory, but would fail miserably in practice. I can see many ways in which the steps would become out of synch, such as when kids "play" on the stairs, or when adults change their minds on going up or down the stairs, and switch direction at the half-way point.

About the only thing stair generators might be good for is to flash LED lights and/or play musical tones in order to amuse people while using the stairs. I have actually seen that done in real life but I could not remember where I saw it. It might have been at a science museum 30 or 40 years ago.

I agree, but that won't stop me from making another stair scene.

Keep 'em coming!