How to Build a Small Scale Hydropower System in Your Backyard

I have been interested in renewable energy for a long time. Recently, I started looking into building a small scale hydropower system to generate electricity in my backyard. Hydropower is one of the oldest and most reliable sources of renewable energy. By harnessing the power of flowing water, it is possible to generate electricity to power your home. Here is everything I learned about building a DIY backyard hydropower system.

Evaluating Your Site

The first step is to evaluate if your site has the necessary conditions to support a backyard hydropower system. There are several factors to consider:

Water Source

You need access to a flowing water source on your property, such as a stream, creek, or waterfall. The water flow rate and volume will determine the potential power output. As a rule of thumb, each gallon per minute of flow can produce about 1 watt of electricity.

Head Height

Head height is the vertical drop distance between your water source and turbine placement. More head height allows you to generate more electricity. Aim for at least 2 feet of head height if possible.


Choose a location to install the turbine that is easily accessible for maintenance and connecting to your home's electrical system. Make sure the site will remain unaffected by floods or debris.

If your property does not meet these criteria, building a backyard hydropower system may not be feasible. Consulting with an expert can help evaluate if your site has potential.

Sizing Your System

Once you have confirmed your site is suitable, the next step is sizing your system. Determine the following specifications:

With this information, you can select an appropriately sized turbine, generator, and other components. As a general guideline:

Consulting a sizing calculator or hydropower expert is recommended to get an accurate system design. Oversizing your system will lead to inefficiency and higher costs.

Choosing a Turbine

There are two main types of turbines suitable for DIY backyard hydropower:

Impulse Turbine

This turbine uses the velocity of water to turn the runner and operates best with high head heights above 30 feet. Common impulse turbine designs are Pelton and Turgo turbines.

Reaction Turbine

Reaction turbines generate power from the pressure and movement of water. They are better suited for low head heights under 30 feet. Propeller turbines, Francis turbines, and Archimedes screws are examples of reaction turbines.

Compare turbine types and select one optimized for your site's specific head height and flow rate. Impulse turbines are simpler to build at home but have limitations.

Generator and Electrical Components

The spinning turbine turns an internal shaft connected to a generator to produce electricity. I will need:

Wiring and disconnect switches are required to safely connect the system to your home's electrical panel. Consult an electrician for installing the wiring.

Constructing Intake, Pipeline, and Housing

To direct water flow into the turbine, I will need:

The intake and pipeline must be large enough to avoid restricting water flow while keeping the system sealed. All housings and containers should be weatherproof and ventilated.

Installing and Testing System

Once constructed, it's time to install the hydropower system:

Having the system inspected by a professional ensures all electrical connections are code-compliant and safe.

Ongoing Maintenance

Like any complex system, expect to perform regular maintenance:

Maintenance ensures your DIY hydropower system will continue functioning safely and efficiently for years to come. Keeping detailed records of system performance over time allows you to spot issues early.

Final Thoughts

Constructing a small scale hydropower system is an involved but rewarding project. With proper site conditions and equipment sizing, homeowners with sufficient DIY skills can build their own backyard hydropower generator. This allows you to produce renewable electricity to reduce your energy bills and environmental impact. If designing and building the entire system from scratch seems daunting, there are also pre-made kits available to simplify the process. Just make sure to research all applicable permits and regulations in your area before getting started. With some diligent planning and preparation, you can harness the power of water to create your own hydroelectric oasis.