If your home site has access to flowing water, it may be a good candidate for a micro hydrogenerator. This miniaturizes the basic 
technology behind the Hoover Dam and other hydro power source: the water forces a turbine to spin, generating electricity and transmitting the power to your home.
Many resources offer the specific technology for constructing a micro hydrogenerator, but the key is a moving body of water, most often a flowing stream. The generator units are not necessarily large in size, rather, their benefits come from small, but continuous, power generation.
Locating your micro hydrogenerator
The system is comprised of several elements, which are placed along the stream course to maximize the “head” or vertical height from the intake and the turbine:
Intake — This unit will divert a portion of the stream’s water flow into the system through the penstock. The intake will include some filtering to prevent clogging debris from entering the piping.
Penstock— This is the pipeline that delivers the water to the turbine. Water pressure builds over the course of the vertical drop. The penstock is sized to maximize flow and minimize friction loss.
Turbine — The water stream makes the turbine spin. This rotation creates electrical power at an alternator, which moves the electricity to your home.
Tail Race— The tail race is piping that returns the water back to the stream course.
Calculate Total Head
The vertical drop between the intake and the turbine creates water pressure of 1 psi for each 2.31 feet. The total head calculation will help to size the turbine and the piping for maximum flow. This is where the help of an engineer will be invaluable to designing a micro hydropower system.
Several resources are available online, including
Brownell Microhydro where they offer a detailed article about calculating your system, as well as selling all components for your own system. They strongly recommend that you utilize an electrician familiar with alternative energy to handle the hookup.
Energy Systems and Designs offers their Stream Engine that harvests water power from your flowing water source. They provide water power sources around the world.
Energy.gov also provides some of the basics on micro hydropower systems.