Micro-hydro power is possibly the most exciting prospect for the home green energy builder. The sad truth is, though, that few people have the necessary resource: running water.

Traditional

There are basically two forms of micro-hydro power available to the home builder. There is a more traditional variant that relies on “head” which is the vertical drop of water. This is usually a fairly major undertaking- typically it involves diverting water out of a stream- often into a relatively smaller pipe- which must then allow the water to drop some distance. That’s a doozy of sentence- just think of it, though, like a re-engineered form of a dam. You build up water pressure inside a pipe and make it fall onto a turbine, which that water subsequently turns. It is then released back into the stream. This is typically some kind of at least moderate engineering project.

Submersible

The other form of micro-hydro is called “submersible” or “in-stream.” The former is probably more descriptive as this form of turbine is often deployed outside of the context of home power- being put on boats, on remote resource monitoring stations that need power, etc. Regardless, I find this form of power to be super-cool. It’s not only constant, but it requires little installation, no major engineering, and does little to interrupt the water. Basically, these are some kind of turbine- either a vertical turbine or a reversed propeller- that turns a magnet. The fair warning on this form of power is that it can be very expensive up-front. There really isn’t much of an option for building it in your own garage, although it can be done- particularly with the reversed propeller approach. But the vertical turbines are far more efficient, requiring less water flow, and being close to thirty times more expensive. The reversed propeller won’t do much for you if you can’t get a constant flow over it of at least 4MPH in most cases.