Joule 3 Dynamo Hub Turns Your Bike into a Portable Generator


If you’re going to expend all that energy riding a bicycle, you might as well turn all that work into usable power. And, if you’re going to turn that work into usable power, you might as well use the most efficient product out there.

Enter the Joule 3 Dynamo Hub, a power hub for bicycles that you can have installed inside a bicycle wheel. The Joule 3 is very small, so you can collect all that power without having to strap a massive generator to your bike. Also a plus is that the Joule 3 is very efficient – 73 percent – which reduces drag added while riding. But, if you want that drag reduced, you can buy the Joule HG, which you can turn on and off, allowing you to ride as if it wasn’t there at all.

The tiny power generator comes in two sizes – one for traditional bicycles, and one for smaller bikes like folding bicycles. The Joule 3 and HG have an output of 6 volts and 2.4 watts, and will cost $150 and $200, respectively, when they become available in November.