hydroelectricity

2 Articles

Low Head Turbine Generates Plenty Of Power

May 22, 2026 by 32 Comments

Engineering design makes all kinds of tradeoffs. Power trades off with torque, strength trades off with weight, and cost can trade off with quality. For designing a hydroelectric turbine, one of the main tradeoffs is hydraulic head with flow rate. Many large dams meant for bulk power generation will go with high head (or medium) designs, and for small dams with low head it’s usually not cost effective to build any generation. But if you’re really determined, you’ll want to build a low head water turbine like this one.

The build aims to use easy-to-find materials and simple tools. It uses 110mm and 160mm PVC pipe to not only siphon water up and over a dam, but to house the turbine as well. The turbine is built from a computer fan and sits inside the pipe with a shaft running through a Y-type fitting to the generator. The generator is built from a scavenged hoverboard wheel, and outputs a reported 3.3A DC at 60V for around 200 watts of power with only around 3m of head. The design allows the turbine to be placed at the point in the pipe that best suits the environment.

[OpenSourceLowTech], the creators of this project, make a compelling case that this build is cheaper than a 150W solar panel and it might even be able to produce more energy as well over certain timeframes, provided there’s a reliable source of water available and the owners of the dam don’t mind someone siphoning water over it continuously. The build video is worth a watch as well if for nothing else than the animation, which documents the build in excellent detail. Generating usable energy from hydropower doesn’t even need this big of a dam; if all you need is to charge your phone this tiny waterwheel will get the job done.

Thanks to [Keith] for the tip!

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A series of trapezoidal steel "buckets" attached together to form a metal water wheel. They are arranged around a square center frame that attaches to a hub for the wheel to spin about. The wheel is next to a stream and four people of various ages appear to be talking around it. A cinder block building with a metal roof is in the left background, and an older, yellow stone building is far off in the distance on the right of the image. The landscape is lush, green, and mountainous.

Open Source Waterwheel

August 20, 2023 by 28 Comments

Here in the West, power going out is an unusual event. But in more remote regions like the Himalayas, reliable electricity isn’t a given. A group of local craftspeople, researchers, and operators in Nepal have worked together to devise a modular waterwheel system.

Based on a 20-30 cm-wide bucket module consisting of only four galvanized steel components, the wheels can be easily built and deployed using resources and tools that are easy to find anywhere in the world. Current test devices generate between 120 and 1,400 Watts of power, depending on the device’s size.

A software tool was also developed that takes the head and flow rate of a location as inputs to calculate the dimensions of the optimal wheel and expected power output for an installation. This lets communities find ideal sites for power generation and calculate the expected costs.

We’ve covered a few other DIY hydropower setups, from repurposed washing machines to custom scratch builds.