Stackable Coke bottle windmill (VAWT) for bottle dynamo

thingiverse

Create a VAWT for charging AA batteries and USB devices with ease. The process involves printing an STL file and utilizing six 2-liter Coke bottles, each cut in half while keeping the screw neck intact. Place them into a holder and fit onto a 6V 3W bottle dynamo. Increase power by stacking bottles for a given wind speed and boost output to around 5W with load matching circuits. A bigger stack with another bottle dynamo on the other end can yield up to 10W of boosted power. Visit your local bike shop for unused dynamos or gather discarded ones. Charge your AA batteries and USB devices affordably with this setup; electronics cost less than $5. A hub dynamo version is also in the works, along with a base to support common dynamos driven by coke bottle VAWTs. Note that this design has not been print tested yet.