How Energy-Generating Sidewalks Work | WIRED

We come here, We go there, we go everywhere. You may be heading for work or lunch in a busy city. You make energy and exercise is good for you. But what if we could re -capture all the free energy and convert it to usable electricity?

That’s a real thing. The systems were installed in dozens of countries. Watch this video. And why stop there? You could put them in discotheques and use this fantastic leg to power lights. Or place them on the Hopcotch grid on the pitch. When you start thinking about it, the possibilities are endless.

But how does it work? And how much power can they generate? Obviously, one person wouldn’t have a big difference, but turn the teeming sidewalks in New York and you can have something. Could we give it all over the world and stop using fossil fuels? Let’s find out!

Watch the bouncy ball

First we need a pedestrian model. No sweat, right? Walking is so easy that it can do it 1-year. In fact, the bipedal locomotion is terribly complicated in terms of physics. Seriously, if you had to learn to walk from a physics model, you would still be in a stroller. Let’s start with something simpler: a bouncy ball.

Believe it or not, it’s a pretty good analogy. We immediately see that there are three types of energy: kinetic energy, gravitational potential energy and spring potential energy.

Kinetic energy He has to do with the movement of the object – it moves faster, the more kinetic energy. If you take the ball and drop, accelerates down, which means that its kinetic energy is growing. But where did the special energy come from?

Answer: It is stored in the gravitational field. It is Gravitational potential energy. The amount depends on the strength of the field (G = 9.8 Newtons per kilogram on the ground), the weight of the object and how high above the ground. When the ball decreases, the energy of gravitational potential decreases and kinetic energy increases.

This is where you can see something very powerful. We call it maintaining energy. This says that if we have a system without energy inputs or outputs – which is called a closed system – it can change the form, but the total amount of energy remains constant.

In the end we have spring potential energy. This is the energy stored in the elastic object when it is compressed. When the ball hits the ground, it deforms and stops. If you had a high -speed camera, you would see how flattened to a fraction of a second, because the kinetic energy is converted into spring energy.

Then the ball turns to regain its shape. The energy of spring potential is transformed back into kinetic energy in the opposite direction and ball trampolines up. Here’s what it looks like:

Animation: rhett allain