A hydro power system captures the "impulse" of flowing water and converts it to electricity - a process termed "mechanical energy". The potential for mini hydro systems depends on the availability of suitable water flow, where it can provide cost effective, clean reliable electricity. A well designed mini hydro system can blend with its surroundings and environment and have minimal negative impacts
Mini hydro systems operate by:
- Water flowing via a channel or penstock to a waterwheel or turbine
- As the water strikes the bucket of the wheel (Pelton Wheel) it causes the shaft of the wheel or turbine to rotate
- The rotating shaft is connected to an alternator or generator. This electrical energy may be used directly, stored in batteries, or inverted to produce utility-quality electricity. Three examples of mini hydros are as below;
A mini hydro facility requires that a reasonable 24/7 flow of water and a fall of water, called head, are obtainable without building elaborate and expensive facilities. Mini hydro systems can be developed at existing dams that have been constructed in connection with river and lake water-level control, and irrigation schemes. By using existing structures, only minor new civil engineering works are required, which reduces the cost of this component of a development.
Mini hydro systems are typically used in remote and country areas to power everything from domestic houses, farms, small commercial buildings and villages. Mini hydro systems are ideal in mountainous remote areas where an abundance of water flow exists. A considerable number of systems are in operation in the South Island in New Zealand. Various sizes of mini hydro systems based on different outputs are availabe for different applications.