Hydroelectric systems

Rivers flow from areas of higher elevations towards lakes or oceans, and as the water moves, it gains kinetic energy. A hydroelectricity system uses that energy to turn turbine blades, causing a shaft to spin, which is connected to a generator. On rural sites they can be set up wherever water falls from a higher lever to a lower level, for example a waterfall, hillside, stream, or where a reservoir discharges into a river.

The type of turbine you need depends on the vertical distance the water falls and the rate at which the water flows. Pelton wheels are the type of turbine most commonly used for small scale domestic generation.

Micro-hydro systems are best suited to rural areas on streams or waterways that flow all year round. The more vertical distance (head) you have between the point where you take the water and the location of the turbine, the more electricity you can generate.

Small scale hydro systems don’t usually need water storage. A portion of the river or stream is diverted through a pipe system to the micro-hydro turbine and generator. Then it’s returned to the same stream or river. This type of system has far less impact on the environment than large scale hydro schemes. But if your small scale hydro scheme does need a form of water storage such as a dam, you’ll need to get consent.