The Power of a Population

The following post is part of the course work for “Live Exchange” the foundational course on communication for The MBA Design Strategy Program at California College of the Arts. The rest of the posts are presented here.

By: Aaron Kettl
As we seek to discover new methods of generating and harnessing energy, there is one source that is worth discussing: the human body. The human body is a machine that processes fuel and converts it into energy. Most of that energy is used to sustain and power itself, but as the human body moves, opportunities arise to capture that energy and transfer it to other forms for potential use. The average human can generate a sustained 100 watts per hour (source). So with a current world population nearing 7 billion (source), that comes out to 700,000 megawatts per hour. If this was sustained for 16 hours this would cover the United States demand for only one day (source). This is assuming the entire world population would be willing to sustain 100 watts an hour for 16 hours a day just so the US can watch Dancing With the Stars on their laptops in the A/C at a Starbucks.

So why haven't we tapped into this potential? Obviously there are many reasons, such as it would be completely unrealistic and inefficient to hire millions of people to build a power plant just to power the US. Instead, there are opportunities to inject energy generating devices into our daily habits and behaviors.

There have been many studies into machines that allow humans to directly convert their kinetic energy into electricity, such as an exercise bike adapted with a generator, (which is an area I have personally investigated, as seen in the image above). A fitness center in Hong Kong (California Fitness) has implemented such an idea to power lights and also charge an array of batteries.

Why haven't more approaches like this caught on? One problem is that even though these devices are effective at transferring kinetic energy they are not efficient. It requires people to consciously stop what they are doing, climb on a machine and exert a heightened amount of work for a period of time just to produce the energy requirements of a single light bulb. For those that like to go to the gym and work out in a spin class that great, but for the rest of us it is not practical.

So how do we tap into the kinetic energy of the population? Energy transferring devices need to be built into people's daily environments so that they work with their daily activities and natural behaviors. This could be done by capturing the energy of rotating doors to directly drive a fan, or through floor tiles that transfer the compressive energy of footsteps into usable electricity, such as those developed by Pavegen. Basically the objects and materials that we come in contact with every day should be modified to serve double duty, to perform a secondary function of energy generation along with their regular duties.

A company called Play Pumps has successfully developed a solution using playground equipment to pump water from the ground while children play. The equipment is geared to transfer rotational movement to reciprocating linear movement that pumps water into tanks for later use. They have successfully implemented this in areas of the world where water and energy is scarce, such as South Africa, Lesotho, Malawi and Swaziland.

The devices by Play Pumps are highly efficient because they use direct drive systems that do not require the transfer of human energy into electricity, which minimizes the energy loss of transfer.

When you think about all the activities you do in a day, the potential for energy capture is enormous. How would you transfer human power to benefit our high demands for energy? Do you think systems like these would be effective?

Aaron Kettl has an Architecture degree and is currently a graduate student in the Design Strategy MBA program at California College of the Arts. Connect with him at akettl@cca.edu