Advanced Search

Please click here to take a brief survey

BikePower! (Pedal-powered Electricity)
Alex Steffen, 6 Apr 06

Sure, you can pimp your pad solar-style (or just greenwire your bedroom), run some microhydro off the stream in the backyard, even set up a rooftop wind turbine. But why make nature do all the hard work?

Most of us could use some more exercise. David Butcher makes some of his own power riding on a pedal-powered generator. It's not a terribly effective way to create the amount of energy the average person living a developed-world lifestyle needs, but the point is as much conceptual as practical, connecting us bodily with the amount of power that runs through our lives (and often goes wasted):

"I used to be a competitive swimmer, and for a number of years, I worked out 6 hours a day, swimming approximately 13 miles. Yes, 13 miles a day. If you pedaled that hard for that long you might be able to run one ordinary refrigerator for 24 hours. To make any kind of significant contribution to your energy supply, you must use the most efficient devices you possibly can. For example, a small refrigerator designed to be powered by solar power would be much more practical. A rule of thumb: if the device was designed to be powered by batteries, even BIG batteries, you might be able to keep up with it.

"If your electric bill shows KWH (kilowatt-hours), take the number, multiply by 4 (assuming you can crank out 250 watts for an hour, which is very ambitious) and that is how many hours you will have to be in the saddle to create the same amount of power. Sorry, it can be depressing. The moral: Using less power is as important, if not more important, than making more."

Which isn't to say that human-powered electricity is pointless. The Jhai project experimented with a bike-powered ruggedized PC and ad-hoc long-distance wifi for areas without electricity, landlines or cellphone coverage, for instance. And there's fun to be had as well: earlier, we covered the idea of human-powered green computer gaming tournament (which I still think would be kind of cool). But most of all, I think having a sense of the kind of actual work done by the machines we use to power our civilization is itself a worldchanging realization, a sort of making visible the invisible

(via the always fun Make, where there's some additional good discussion of the concept)

Bookmark and Share


You can now see video of my solar experiments at and, including my solar backpack and bike light system.

Pedal and hand crank people power is going to be a useful stepping stone into the renewable economy. Perhaps as important as the computer in the one laptop per child project is the hand crank electric generating system and the concept of battery switching.

Emergency systems like a solar/dynamo flashlight/radio with a pack of rechargeable batteries can provide low voltage DC power under almost any condition. Add a bicycle and you have a bridge toward hybrid vehicle and household power.

Imagine an affordable and readily available solar rechargeable reading light so that every child who wants to has a chance to read in bed.

Posted by: gmoke on 6 Apr 06

I would still like to see a fitness gym do this. Could users pay for their own electricity use? Would different techniques yeild more energy... (originally thought up for a Ad Busters competition)

Posted by: adrian cotter on 6 Apr 06

This is a fun machine, but here is my math:

One hour, at 250w, is 1/4 kWh ... 2 cents worth of electricity.

But wait, I'm not down on pedalling:

One hour, at 12mph, is a six mile trip out and back. At the national fleet mileage of 22 mpg that saves a half gallon, or (at my current prices) $1.40 worth of gasoline.

Maybe pedaling and bicycles to together ;-)

(While it is sad that people currently drive to the gym and pedal, without making electricity, I'm not sure making a few fractional kWh would every balance the energy equation ... and the car trip over.)

Posted by: odograph on 7 Apr 06

Is there any info on how to build a hand crank? This would be useful for emergency light, emergency phonecalls, and emergency radios. In many emergencies it's all about being able to communicate! Thanks!

Posted by: Lucas Gonzalez on 8 Apr 06



MESSAGE (optional):

Search Worldchanging

Worldchanging Newsletter Get good news for a change —
Click here to sign up!


Website Design by Eben Design | Logo Design by Egg Hosting | Hosted by Amazon AWS | Problems with the site? Send email to tech /at/
Architecture for Humanity - all rights reserved except where otherwise indicated.

Find_us_on_facebook_badge.gif twitter-logo.jpg