Micro-Hydro

A system to capture the potential and kinetic energy in flowing water to generate electricity through a turbine that spins a generator. A small scale form of hydroelectric power or hydropower, micro-hydro systems are typically less than 100 kilowatts. Micro-hydro systems are usually run-of-the-river systems that divert a portion of the stream flow and send it downhill through a pipe (called a penstock) to the turbine, where it spins the shaft of a generator. The water is then returned to the same stream at a lower point. These systems typically do not involve a dam across the whole stream, and do not use a water storage reservoir. This keeps the stream open for fish and other biodiversity.

The most important thing is to look for a good site. You need a stream that you are allowed to divert water from, that has enough water flow and a significant drop in elevation over a short distance (called the head). If you have access to such a stream, you need to check what local water and environmental permits are required to divert some of the water. Also consider what kind of turbine you need (low-head or high-head, low-flow or high-flow), and how long and how wide the penstock pipe will have to be for good flow and pressure.

To estimate how much hydroelectricity you could generate from a flow of water, measure the head (vertical distance the water drops), and flow rate of water. In metric units: 9.81 x Head (metres) x Flow (litres per second) x Turbine Efficiency (typically 0.6) = Power (Watts). In Imperial units, multiply 0.18 x Head (feet) x Flow (gallons per minute) x Efficiency (0.6) = Power (Watts).

Very clean, zero-emission, and continuous source of renewable electricity with minimal impact on the environment. Because it runs 24/7 as long as the stream is running, you can use a small capacity generator to generate a large quantity of energy over a period of time.

Hydroelectric power is the source of over 60% of the electricity used in Canada. Hydropower is generally reliable, continuous, and relatively clean energy, which is why large data centres for such companies as Dell, Yahoo, and Apple are built in places like the Pacific Northwest region of the USA, where hydropower is near at hand.