Small Scale Hydroelectric
This is the modern version of the old water mill but generating electricity not driving equipment. The large-scale modern equivalents are things like the Hoover Dam system. Most Hydro schemes have one obvious advantage over other renewables in that they produce power continuously, 24 hours per day.
Basically you use the force of running water to power a turbine, typically a Pelton wheel that is a series of cups attached to a hub. A jet of water is aimed at the cups, and the resulting force on the cups causes the turbine to spin. The turbine generates DC electricity by driving an electric motor in reverse.
The most important things to consider are how much height you’ve got (often call 'head') and how much flow you've got. Generally it is good not to not divert more than 20% of the water flow though your turbine, and to return any diverted water back to the stream just below the turbine.
Running water 'stores' energy in one of two ways. Potential energy when it is stored in a Dam (for low flow but high head) or Kinetic energy (for high/fast flow but low head).
The simplest types are 'Run-of-river' systems. These use little, if any, stored water to provide water flow through the turbines by sitting them directly in the river. Be aware though these can experience significant fluctuations in power output as the flow of the river varies.
The more common type are 'Storage' systems using dams to give enough storage capacity to offset seasonal fluctuations in water flow and provide a constant supply of electricity throughout the year. Larger dams can store several years worth of water but are unlikely to be practical for domestic users.
These systems are easy to design but you need very careful calculations to work out the available power you have. For example you can't just dam an entire stream if you want stay friends with your downstream neighbours, be they animals or humans.
If you think you've got an opportunity for a hydro scheme just give us a call.