Essentially, micro-hydro is a scaled down version of a normal hydroelectric system, and both utilize the power in moving water to generate electricity within the system. Micro-hydro systems are proven to be low-impact, renewable sources for on-site power generation. It’s amazing to think how long we’ve been using water to generate electricity, over 2000 years according to some.

From milling grains, sawing wood and pumping water – we’ve been using traditional waterwheels to provide the necessary mechanical power to complete such tasks. Eventually improvements were made towards the efficiency of early models which led to the invention of the hydroelectric turbine in the 1800’s.

Hydroelectric power is driven by the natural cycle of water, which is broken down as follows:

• Solar energy causes plants to transpire, and water to evaporate from lakes and oceans
• The water vapor condenses into the clouds which produces precipitation
• Mountains receive a great portion of this precipitation
• This spawns the occurrence of downward flow into the rivers and streams
• The water is then driven from the streams to the oceans
• The moving water contains kinetic energy, which results in hydro power

To understand a micro-hydro system, we first need to look at larger scale hydroelectric power generation set up such as the Hoover Dam. A large system such as this diverts the water through turbines, which cause generators to spin and produce massive amounts of electricity. Due to the scale of such a project, there are obvious requirements for tremendous amounts of land in order to compensate for factors like flood control. Back in January 2007, The Energy Information Association (EIA) stated that 16% of the world’s electricity is supplied by large scale hydroelectric plants – this percentage has likely increased since then.

Micro-hydro can be defined, under general circumstances, as electricity generation with a capacity up to 100kW. Many of the systems which fall under this capacity are referred to as run-of-river, which don’t require an impoundment and diverts a fraction of the stream’s water through a pipe downhill passing through a small turbine.

Type of Hydro-electric systems

AC/DC Systems – The mass majority of micro-hydro systems use batteries to store the electrical energy. The water passes through a turbine, which drives the generator and charges the battery tank, and just like a solar powered system, the energy is then passed through an inverter which converts the DC power into Alternating Current – in order for the system to power common household items.

High/Low Lead Systems – A micro-hydro system and its potential energy output is determined by a combination of two factors: head and flow. Power can be generated from either a high head/low flow, low head/high flow, or any given amount in between. As it stands, high head is generally considered to be 10 feet or more, with specially designed systems required for heads smaller than the standard threshold of 10 feet – which is needed when there are large amounts of water required.