Microhydro Turbines

It is estimated that over the life of any active, renewable power system, micro-hydro may be the most cost effective way to produce power on your property, depending upon on the strength of the running water. You’ll want to use a power calculator to determine what sort of micro hydro turbines would best suit your needs and environment.

First, it’s a good idea to figure out just how much potential power is available in the moving water on your property. First find out if what the water speed is during different times of the year. The minimum and maximum flows will be used to generate a flow rate. With the design you come up with, you can then design a system that uses an appropriate amount of head (the vertical distance from the intake to the turbine) with as little friction losses as possible.

From this design, you can figure out how big and what sort of a micro-hydro turbine you should get. You’ll also be able to investigate (before you buy anything) what regulations, if any, pertain to your creek or stream. You may have to hire a professional to make an impact study or some similar legal statement saying that you promise not to dam up the river or cause any loss of fish habitat.

Microhydro turbines generally come in one of two types. Impulse microhydro turbines are the most common and are open to the air. Water is forced through a relatively small pipe and then splashed over the turbine wheel. These are best used with streams that have a moderate to large head of at least 30 feet.

For streams with smaller heads, the reaction-type of small micro hydro turbine is the preferred device. These are more efficient at lower volumes and are fully enclosed to increase pressure on the wheel while directing the water current over a particular portion of the wheel. They are a bit more expensive, but are also very tidy. They also don’t spray water all over the place.

Though the technology has been around for a very long time, there are relatively few micro hydro turbine manufacturers to choose from. However, should you consult with a professional engineer (and it is highly recommended you do), he or she will be able to recommend a product with a good build quality and warranty that suits your current and future needs at the chosen site.

The turbine you choose will be able to output either alternating (AC) or direct current (DC), depending on what sort of power you’ll be using. Often when used to run lights or pumps, DC power can be used directly. Those who sell power back to the company or run usual household appliances with the generated current will probably want to take an AC feed and condition it for use with the existing grid system.