Low Head Turbine Generates Plenty Of Power

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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Hackaday Links: August 10, 2025

We lost a true legend this week with the passing of NASA astronaut Jim Lovell at the ripe old age of 97. Lovell commanded the ill-fated Apollo 13 mission back in 1970, and along with crewmates Jack Swigert and Fred Haise — along with just about every person working at or for NASA — he managed to guide the mortally wounded Odyssey command module safely back home. While he’s rightly remembered for the heroics on 13, it was far from his first space rodeo. Lovell already had two Gemini missions under his belt before Apollo came along, including the grueling Gemini 7, where he and Frank Borman undertook the first long-duration space mission, proving that two men stuffed into a Volkswagen-sized cockpit could avoid killing each other for at least two weeks.

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Build Your Own Hydroelectric Dam

We have to admit that we often think about building unusual things, but we hadn’t really considered building our own hydroelectric dam before. [Mini Construction] did, apparently, and there’s a timelapse of the build in the video below.

We wished this was more of a how-to video, although if you are handy with brickwork, the mechanical construction seems straightforward. Presumably, you’d need to understand how much force the water had but we don’t know if there was math involved or just seat-of-the-pants design.

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A Hydroelectric Dam, Built Out Of LEGO

Hydroelectric dams are usually major infrastructure projects that costs tens of millions of dollars to construct. But they don’t have to be — you can build your own at home, using LEGO, as [Build it with Bricks] demonstrates!

The build is set up in an aquarium with a pump, which serves to simulate flow through a river system. The LEGO dam is installed in the middle of the aquarium, blocking the flow. It has a sluice gate in the lower section to feed water to a turbine for power generation. The gate is moved via a rack and pinion. It’s driven by a LEGO motor on a long shaft to keep it a safe distance from the wet stuff. The dam also gets a spillway to allow for overflow to be handled elegantly. Meanwhile, a second motor acts as a generator, fitted with a fairly basic turbine.

Hilariously, the first build fails spectacularly as the hydrostatic pressure of the water destroys the LEGO wall. A wider base and some reinforcements help solve the problem. There’s a better turbine, too.  It’s all pretty leaky, but LEGO was never designed to be water tight. As you might imagine, it doesn’t generate a lot of power, but it’s enough to just barely light some LEDs.

It’s a fun way to learn about hydroelectric power, even if it’s not making major amounts of electricity. Video after the break.

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Hackaday Links: August 6, 2023

“Have you tried turning it off and on again?” is a common tech support maneuver that everyone already seems to know and apply to just about all the wonky tech in their life. But would you tell someone to apply it to a reservoir? Someone did, and with disastrous results, at least according to a report on the lead-up to the collapse of a reservoir in the city of Lewiston, Idaho — just across the Snake River from Clarkston, Washington; get it? According to the report, operators at the reservoir had an issue crop up that required a contractor to log into the SCADA (supervisory control and data acquisition) system running the reservoir. The contractor’s quick log-in resulted in him issuing instructions to local staff to unplug the network cable on the SCADA controller and plug it back in. Somehow, that caused a variable in the SCADA system — the one storing the level of water in the reservoir — to get stuck at the current value. This made it appear that the water level was too low, which lead the SCADA system to keep adding water to the reservoir, which eventually collapsed.

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Miniature Concrete Hoover Dam Is Tiny Engineering Done Right

Growing up, we got to play with all kinds of things in miniature. Cars, horses, little LEGO houses, the lot. What we didn’t get is a serious education with miniature-sized dams. This recreation of the glorious Hoover Dam from the [Creative Construction Channel] could change all that for the next generation.

The build starts with the excavation of a two-foot long curve in a replica riverbed. A cardboard base is installed in the ditch, and used as a base for vertical steel wires. Next, the arch of the dam is roughed out with more steel wires installed horizontally to create a basic structure. The cardboard is then be removed from the riverbed, with the steel structure remaining. It’s finally time to pour real concrete, with a foundation followed by the main pour into foam formwork. The dam is also given 3D printed outlets that can be opened to allow water to pass through — complete with small gear motors to control them. The structure even gets a little roadway on top for good measure.

The finished product is quite impressive, and even more so when the outlets open up to spill water through. Such a project would be great fun for high school science students, or even engineering undergrads. Who doesn’t want to play with a miniature scale dam, after all? Bonus points if you build an entire LEGO city downstream, only to see it destroyed in a flood.

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Solar And Wind Could Help Support Ethiopia’s Grand Dam Project

Ethiopia is in the midst of a major nation-building project, constructing the Grand Ethiopian Renaissance Dam (GERD). Upon completion, GERD will become the largest hydropower plant in Africa, providing much needed electricity for the country’s growing population.

The project dams the Blue Nile, a river which later flows into neighbouring Sudan, where it merges with the White Nile and then flows on to Egypt. Like all rivers that flow across political boundaries, concerns have been raised about the equitable management of the water resources to the benefit of those upstream and down. Too much water dammed upstream in GERD could have negative effects on Egyptian agriculture reliant on river flows, for example. Efforts are ongoing to find a peaceful solution that suits all parties. Recently, suggestions have been made to supplement the dam’s power output with solar and wind to minimise disruption to the river’s users.

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