[Little private fountains]
Gent’s King Albert park has a huge public fountain. This fountain does not only provide refreshment to the visitors of the park, it is also a great source for hydropower.
In a performance in Summer 2010, Jari Suominen and me attached water wheels to that fountain, in order to produce electricity. Then we used this self-made electricity to drive a series of small electric bucket fountains, which we rented out to people in the park.
In an attempt to address the various tastes of our customers, each of the little fountains was designed in an individual way. Scroll down to find an overview of the models that we have provided, together with a description of their distinct features.
If you are interested in recycling fountain energy by yourself – there’s a short technical description of our setup at the end of this page.
And last but not least, you can find more photos of the performance here.
The concept: big fountain powers small fountains – download hires
Attaching the water wheels – download hires
Our rental station – download hires
Installing a private fountain download hires
Kids enjoy the “Blue Danube” – download hires
Each customer gets the fountain that fits his taste – download hires
• Plays Strauss’ “Blue Danube Waltz”
• Integrated underwater LED light show
• Spill is modulated according to the music
[ Hires image ]
• Hypnotic in-spill LED-strobe
• Manual spill shape adjustment
• Dark tent emphasizes hypnotic effect
[ Hires image ]
• Water spill drives a little water wheel
• Almost perpetual motion technology
[ Hires image ]
For producing the electricity, we used Shimano bicycle hub generators as they provide already a serious amount of electricity, even when turned with low rpm. So we could avoid the use of gears in our system. Another advantage was their reliable operation in moist environments: They’re designed to work even in heavy rain, so some shower from the fountain didn’t destroy them right away. The water wheel’s blades were cut out of standard PVC drain pipes. That made the whole setup quite cheap.
The voltage that an electric generator produces depends on the rotation speed and on the resistance of the circuit that it drives. Due to the large fountain as power source, in our case the rotation speed was very steady. And in order to have an efficient system, we wanted the generators to produce as many Watts as possible. So we tried out different resistances on the generators. You can see in the diagram below, that one generator produced more than 5 Watts (ca. 400mA, 14V), when the resistance of the circuit that it drove was about 28 Ohms.
Shimano RUI diagram – download hires
Of course, we couldn’t use the AC that came directly out of the generators. So we rectified it to DC voltage and smoothed it with some large caps. For the small fountains that also involved microcontrollers (“Blue Danube” and “Pentathlon”), we finally cropped the voltage with some low-drop regulators (and huge heatsinks). That’s it about how we generated the power. It all worked fine and seemed to be a nice system which could be also used for other low-power electricity needs in the city.