Selecting the Right System

Choosing the right type of micro hydropower system for your site depends on its unique physical characteristics and conditions.


As water flows downstream, its gravitational energy can be converted into electric power by a hydroelectric system.  Many smaller rivers and streams are capable of providing micro-hydro power for local use and to be fed into the power system grid. While different sites will have unique systems that are best here are several common components that make up a micro hydropower system. Other systems may not have a penstock, instead having the intake feed directly into the powerhouse, including the turbine, located alongside or as part of the dam.

Micro hydropower system

Intake: A structure that diverts water from a natural waterway into the turbine

Canal: A structure that moves water from natural waterway to the forebay

Forebay: Impoundment or reservoir immediately above a dam or intake structure at a hydropower plant

Impoundment: Body of water created by a structure that obstructs flow, such as a dam

Penstock: A closed conduit or pipe for conducting water from the forebay to turbines in the powerhouse.

Powerhouse: The structure that houses generators and turbines at a hydropower facility

Turbine: A machine that produces continuous power in which a wheel or rotor revolves by a fast-moving flow of water.

Image from DOE’s Office of Energy Efficiency and Renewable Energy.


Site Restrictions & Considerations

Water Use Restrictions

There may be laws that restrict the amount of water that can be diverted from a stream, either permanently or temporarily, requiring a system to limit water input.

Stream Wildlife

Many streams support fish and other wildlife whose habitat could be affected by the installation of a micro-hydro system.

Streamside Equipment

The size and environmental impact of any micro-hydro installation has to be considered, both for its construction and its operation. Other disturbance of existing ecosystems, should also be evaluated (see Environment for more).

Site Survey Checklist

Before getting started on technology selection, it’s important to understand your site. Use this checklist to make sure you understand the characteristics of your site and it’s potential for microhydro. While understanding environmental impacts of microhydro is a priority, it is also critical to make sure your site is suitable for a microhydro system before moving further along in the process.

  1. Environmental Impacts
  2. Measure head
  3. Measure site flow
  4. Calculate estimated power

If your site is suitable, the next steps include following local, state, and federal regulatory requirements, as well as determining how you will finance the installation and ongoing maintenance of the system.

Evaluating Viability

How can you tell if your existing dam can support a micro hydropower system? Read more about the key characteristics of your site to determine whether a micro hydro system is an option for your dam.
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Determining Head and Flow

How do you measure the head and flow at a dam? Read more to understand why these measurements are important and how to find them.
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Calculating Maximum Power

Every site has a maximum amount of power it could potentially generate. Read more to understand how to calculate a dam's maximum potential power, and what that power output means.
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Interactive Mapping Tool: Testing Site Potential

Using the latest topographic information provided by the New York State GIS Program Office, the Bard team built an online tool that allows you to explore any location to determine available head, flow, and overall project viability.
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Types of Turbines

There are many turbine options available. Determining which turbine is right for you site depends on your sites available head, flow rate, and other concerns.
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Fish Passage

For many sites, installing technologies to allow for fish and other aquatic species to pass a dam will help reduce the environmental impact of a micro hydropower system.
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Options for Connecting your System

Understand the different options available for connecting your system to the grid, or using your system to power your home. Read more.
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