Human as a Source of Free Energy?

We could power our cities just by walking, heat the next-door building by taking a train, and our children could light up the park just by playing on the playground (or so some say).

8. June 2021
6 minutes
Adam Petrek
Human as a Source of Free Energy?

We are walking power plants. Every breath you take, every move you make, every bond you break, every step you take, I’ll be watching you. (No, not really; I am neither Sting nor Google.) You generate power that goes unused. What if we could harness it to save money, protect the planet, and maybe even have little fun?

We could power our cities just by walking, heat the next-door building by taking a train, and our children could light up the park just by playing on the playground.

Charge Your Phone With Wearables

There is considerable research into wearables that can convert kinetic energy (the movement energy) into electricity. None is as efficient as a footstrike.

The most comfortable solutions require you to just get a special insole for your shoes or put a small generator into your boot heel.

Dielectric Elastomer Powered Boot Generators (Source)

The more effective ones require you to wear various tapes and gadgets on your arms and legs or to wear a unique backpack.

Suspended-load Backpack Undergoing Vertical Excursion (Source)

They still have some way to go before becoming efficient, and the latter solutions are more suited for soldiers on the move rather than the general public. However, there might be different solutions that cities can implement to harness our kinetic energy and create a free, renewable energy source.

Powering Your City One Step at a Time

A decade ago, both London-based Pavegen and Chicago-based Powerleap had terrific plans for using kinetic energy. The Powerleap came up with a prototype for a playground that would harness the energy from children’s movements and use it to power the park lights at night.

The Pavegen wanted to use their power-generating tiles to illuminate bus stops and to light up pedestrian crossings as people cross them.

Sadly, I haven’t heard about Powerleap since then, and I wondered why I still don’t see the promising Pavegen technology everywhere. Lewis Page wrote about Pavegen for the Register in 2015 that the amount of harnessed energy is “utterly insignificant compared to the energy demands of modern civilization.” I only guess that Powerleap had stumbled over the same issue.

Yet, the Pavegen is still alive. Since then, Pavegen had introduced its technology to cities worldwide, though primarily to showcase the technology rather than its serious application. At the beginning of April 2021, the Leighton Buzzard station in Bedfordshire had installed two Pavegen walkways that power two USB charging benches and a digital screen from commuters’ footsteps.

The issue with this technology is that it requires an extreme frequency of steps to be effective. Therefore it can be useful, but only when applied on walkways with high pedestrian traffic. If one day it becomes practical enough to use at home, I will be the first to place a few tiles in front of my fridge to reduce my electricity bill.

Soundpower Corporation, Japan, made their own tiles to convert vibrations into electricity. They even went as far as to promise a power-generating home flooring and staircases in 2017, but they had to postpone.

At the mention of stairs, I recall the image of Rocky running up the stairs in front of the Philadelphia Museum of Art. I think to myself that maybe I too should get off the chair and at least try to run up the stairs in my house. It would be so much more motivating if I lowered my electricity bill every time I did so. As I haven’t seen any significant news regarding Soundpower’s progress, I assume it’s still only a work in progress.

You’re Hot and Don’t Let Anybody Tell You Otherwise

French company Paris Habitat, and the engineers from the Kungsbrohuset building (referred to as K from here on) in Stockholm, Sweden, came up with a different approach, and they might be onto something. They are saving money and protecting the environment by utilizing the body heat from commuters.

The construction company, Paris Habitat, built a heat extraction system that extracts heat from a metro tunnel and uses it for heating the Beaubourg building’s 20 apartments. In fact, it makes up 35% of the heat the building needs. This way, you are saving a lot of money and protecting the environment by reducing energy-related carbon emissions.

The K building is utilizing both cold water and body heat to regulate the building’s temperature. They use the water from Klara Lake to cool the neighboring Stockholm Central Station. When the water returns from the Central Station, it is warmed by the excess body heat from inside the station. The warm water is recycled and supplies 15-20% of the K’s heating requirements.

It All Sounds Amazing But...

In theory, harvesting energy from steps seems like a fantastic idea. I wouldn’t mind reducing my electric bill just by walking around the house. I love the idea that I could just go for a jog in the park and power the nearby lights or charge my phone. Imagine the city savings if the streetlights were charged from vibrations caused by traffic. It might be possible in the near future, but we are not there yet. It will have to become much more effective to overcome its small area of potential use.

Nevertheless, it is a beautiful dream to dream. Thus, I would advise cities to hold off the acquisition of power-generating tiles. On the other hand, I encourage you to follow the examples of Paris and Stockholm to utilize the body heat in your city’s stations or other enclosed public spaces if there is an opportunity to do so. The money savings are worth it, and the Earth will thank you.