Umbrella-based windmills

[Niklas Roy] is at it again. He’s applying wind power to his projects by using umbrellas. He was inspired by the shape of an anemometer, and umbrellas turned out to be a great choice because they’re cheap and easy to find.

Anemometers measure wind speed by capturing it with egg-shaped sails (in fact, we’ve seen them built from plastic Easter eggs before). The umbrellas have a much larger area and will capture more wind. Still it’s a big jump from measuring wind speed to generating energy. That’s why he’s not trying to generate electricity, but instead using the mechanical force directly. He took a page from one of last year’s projects and used the dual umbrella setup to power a music box, thereby reinventing the wind chime. The triple-umbrella unit seen above serves as a bubble machine, driving a series of plastic rings through a soapy solution and letting the wind do the rest. We’ve embedded his demo video after the break.

13 thoughts on “Umbrella-based windmills

      1. If the wind gets outside a narrow range they will be destroyed, and since they are on a rotating thing they will be forced in every direction (reverse/sideways/angled) towards the wind meaning destruction is assured.

  1. No comments yet? This is interesting. One (relatively) simple modification would be to implement a governor using a pulley linked counterweight to automatically furl the umbrella (or release some fabric) to prevent overspeed. The weight (located on the center shaft of an umbrella) could possibly be installed above the struts, with a wire extending to a pulley attached to the base of a spoke; for less expense, they could be coupled to each other’s mechanisms, which could be done with an inexpensive static (relative to rotor) capstan at the center (to guide the wire/cable/rope). Not sure if I’ve seen this before, but the idea of using umbrellas as vanes cuts the labor on this to near zilch, if you have a suitable hub and generator.

  2. An A++ for ingenuity. However wholly unworkable here on the Eastern Edge of the Kansas High Plains. Very few days when the sail could survive, and you would get bubbles, rather then soapy solution traveling down wind.

  3. A cheap mod to help keep things from flying apart (less) in the wind would be to tie some poly string to the ends of the spokes and connect to the central shaft of each umbrella to keep it from popping inside out during high wind.

  4. its going to be a pretty low RPM device, most generators/alternators need some pretty good RPM, to work, Although this is going to have a pretty good amount of torque so one might be able to gear it up (im curious if it could drive a cordless drill backwards, they have a pretty good speed reduction gearbox)

  5. The so called “golf” style umbrella may be a good choice here, especially under gentle trade wind conditions. These brollies are designed to turn inside out in high winds BUT simply pop back to shape again afterwards. Yah! I live in a region (Wellingon, New Zealand) that’s prone to gusts, & swear by the golf style ones for rain protection (although they are too large for tight footpaths etc). They’re pretty cheap ( ~ US$5 ) & although occasional inverting pop outs occur we’ve never lost one yet!

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