Gallery: WEZA Foot-Powered Portable Energy Source


What’s a more renewable form of energy than human energy? We’ve seen it before with the human-powered gyms in Hong Kong, and here’s a portable energy source that’s powered by the spring in your step. We just discovered this amazingly useful gadget at CES, and can’t wait to get our hands on one. The Weza Portable Energy Source from Freeplay can produce enough power from a few footpumps to jump-start a boat or automobile battery and power a laptop, light or a variety of other electronics. If you were stuck out in the middle of nowhere, you could even use to charge your cellphone!

Weza is a Swahili word that means “power,” and how fitting of a title. The small device provides power to products via a 12 V DC cigarette lighter adapter, saving your butt in emergency situations and bringing renewable power to all your gadgets. Weza has an LED display bar to show battery and input effort levels, and the battery is a safe non-spill, 7 amp-hour lead-acid gel battery. Depending on the effort applied, this creates electrical energy of 25 to 40 Watts. It even comes with a 2 year warranty. Here’s a great individual solution to creating usable energy, off-the-grid, and using your own blood, sweat, and tears. Well, maybe just sweat.

+ WEZA – $299 from Freeplay


or your inhabitat account below

Let's make sure you're a real person:


  1. halfthy May 27, 2012 at 5:27 am

    Good product, the concept can be applied in cycle/trademills. Correction to whoever supplied you the the definationof WEZA, its not as you stated “power” but weza means “to be able.” While power = nguvu in swahili.

  2. Keith January 14, 2008 at 4:54 am

    I made a mistake when calculating the energy needed for a mobile phone…sorry!

    The average mobile phone battery stores about 10-20 thousand joules,
    not 3-4 joules as I said before…eg my n73 battery is
    3.7 Volts x 1000 mAmp-hours = 3.7 Watt-hours = 13,200 Joules..

    So to produce enough energy to recharge it with foot power
    would take about 5 minutes of pumping … eg 40 Watts x
    300 seconds = 12,000 Joules.


  3. Keith January 14, 2008 at 3:49 am

    “this creates electrical energy of 25 to 40 Watts” …

    Energy is not measured in Watts…power is! Power is the rate at which energy is used.
    Energy is measured in Joules (or kilojoules, or watt-hours, or watt-seconds).

    If 1 joule of energy is used in 1 second, then the power rate is 1 watt…if 1 joule is used in 1/1000 of a second,
    then power is being used at the rate of 1000 watts.

    Electrical devices are usually rated in watts, but to calculate how much energy they use you have to multiply by how long they are used. For example a smallish TV set might be rated at 100 watts. That means it uses energy at the rate of 100 joules per second. If you run it for an hour, then it uses 100x60x60 joules, which is also know as 100 watt-hours, and will probably appear on your energy bill as 0.1 kilowatt-hours.

    People are very low producers of power. The average fit person can generate power at the rate of 75-100 watts for about 8 hours before becoming exhausted. That means, if you pump this device continuously for 8 hours, you have generated enough energy to relax and watch TV for the next 6-8 hours. Or if you want to sell it back to the grid, you would earn maybe one or two cents (figuring energy costs are about 10-20 cents per kilowatt-hour).

    On the other hand, a mobile phone battery stores only about 3 -5 joules of energy. So if you pump this device for just one second you have produced more than enough to fully charge your phone!

    So, very good for small devices such as phones, flashlights, ipods, maybe even laptops. But no good for the average household appliance like TV, heater, stereo, computer, refrigerator and so on.

  4. peter gusztav January 13, 2008 at 9:15 pm

    This should have been made for cars. Imagine always pedalling like this in your car to get more energy.i posted this with extra weird comments,

  5. Matilda January 13, 2008 at 8:40 pm

    Now if they had a cool way to:
    1. Integrate it with a video game so that you could do it competitively
    2. Plug it in to any wall outlet
    3. Make the electricity generated go back into the grid.
    My kids would try to beat each other’s records while getting healthier and cutting my power bill.
    When Sony can show me how I can actually MAKE money by dropping $600 on a PS3, I might actually drop $600 on a PS3.

  6. shehla January 12, 2008 at 3:01 am


  7. Adam January 11, 2008 at 12:24 am

    Very cool. Looks like I can keep my XO-1 running anywhere now… :-)

  8. Amanda January 10, 2008 at 5:40 pm

    Very interesting…so many possible uses. What a great thing to have in your emergency kit.

  9. Daniel January 10, 2008 at 4:50 pm

    What I’d like to know, and it’s something they never seem to state, is how many pumps with the pedal will it take to charge the entire battery? I’m assuming many, many, many.

get the free Inhabitat newsletter

Submit this form
popular today
all time
most commented
more popular stories >
more popular stories >
more popular stories >
Federated Media Publishing - Home