hydroelectric dam

2 Articles

The Many Questions And Challenges With DIY Hydroelectric Generators

January 6, 2026 by 13 Comments

The concept of building your own hydroelectric generator seems simple at face value: use gravity to impart as much force as possible onto a turbine, which spins a generator, thus generating electricity. If you’re like the bloke over at [FarmCraft101] trying to DIY this with your farm pond and a lot of PVC pipes, you may have some significantly more in-depth questions, especially pertaining to what kind of generator to use. This and other questions, some of which were raised after the previous video in which the first prototype generator was assembled, are answered in this follow-up video.

When you DIY such a hydroelectric system, you have a number of options when it comes to just the turbine design alone, with the Kaplan-style turbine being one of the most straightforward ones – especially if you use a fixed pitch instead of adjustable – but you can go pretty far in the weeds with alternatives. As for the sharp drop-off after the turbine in the used design, the technical term is a draft tube, which is actually more efficient in this kind of low head, high flow hydroelectric dam situation.

After getting his money back for the unusable ‘3 kW’ generator, there were three options left: try an EBay special, get a purpose-built one from a US company, or rewind an alternator stator for higher voltage output than the standard 12/24V. Ultimately option four was chosen, as in ‘all of the above’, so that comparison is coming up  in a future video.

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A Hydroelectric Dam, Built Out Of LEGO

January 27, 2024 by 10 Comments

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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