This is a project that has been simmering for two years, ever since we made, transported and installed an undershot water wheel on a small creek. The wheel has been spinning merrily and looked nice, but we always wanted it to generate hydroelectricity. It took a while but the last week a couple of LED lanterns were first lit using locally produced hydropower!


For this project, opit bought a permanent magnet 3-phase alternator by Windzilla on Ebay. It has a speed-up gearbox which we needed to use (the wheel turns at 5RPM, which is way too slow to be used directly) and a convenient foot mount. pwf sourced the other parts (pulleys, sprockets, chains, belts, etc.), welded the mount for the generator and attached it to the wheel frame, a box for the generator and the chain sprocket, and assembled everything together. Here’s how the wheel looks now:


The generator with its gearbox is attached to the wheel by using two up-reductions. The wheel turns a 500mm diameter V-belt pulley mounted on the same axis which turns the shaft with a big chain sprocket which in turn is attached to the generator.

Here’s the generator and the chain sprocket, minus the large pulley:


The generator – side view. Belt tension mechanism is at the lower right.

The wheel without the generator cover. The generator turns at about 150RPM – many times faster than the water wheel.

Later on pwf hooked it up to the LED lanterns he made. Here’s the overall view of this system, with the old water mill machinery at the end: