# Portable wind turbine

This project, by designers Marcos Madia, Sergio Ohashi and Juan Manuel Pantano, explores the idea of a folding wind turbine. The artwork suggests the turbine could generate 600 watts, what do you think, O readers? [via Inhabitat]

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### 9 Responses to Portable wind turbine

1. Unfortunately there is virtually no agreement among the major wind turbine manufacturers, let alone independent designers such as these, as to where the power rating comes from. I can safely say, looking at the height of this turbine off the ground and nothing else, that 200 watts is a pipe dream.

• …that it’s a very pretty folding design. It’s just that turbines need clearance from surrounding obstacles in order to interact with the wind. Ten feet just ain’t gonna do it.

• It does look like it might get to around twenty feet, and its portable enough and light enough you could set a few of these up on the edge of a flat rooftop and get more wind.

2. Perhaps … this would be handy if you needed to power your temporary research base on the peak of some mountain somewhere?

3. the first thing I thought of was the military’s OE 254 antenna, it breaks down into more or less a duffle bag size and can be put up in 5 minutes by 2 guys (if you’re good you can do it by yourself), instead of an antenna up top put a little wind turbine. the tech involved in that is a lot more down to earth than this industrial designer’s wet dream.

4. the mathematical maximum power you can get from a perfect windmill is
P_max= 8/27 *(rho *V^3) *pi R^2

(a good reference on the topic is http://web.mit.edu/drela/Public/web/qprop/qprop_theory.pdf )

It looks like R~= 1 m
1 Watt= 1Joule/1second
1 Joule =1 Newton *1 meter
1 Newton= 1 kg *1 m/s^2

taking rho~=1.2kg/m^3 @1atm @20C (you can calculate it from rho=P/RT, if you want)

we have:
P_max = 8/27 *(rho *V^3) *pi R^2
600 W = 8/27*1.2kg/m^3*V^3*3.14*1m^2
600 J/s = 1.12 kg/m *V^3
600 Nm/s *0.895 m/kg = V^3
537 [kg*m/s^2]*[m^2]/[kg*s]= V^3
537 [m/s]^3=V^3
V=8 m/s ~=18mph

however, at a more reasonable 10 mph (4.5 m/s) the maximum theoretical power out is 100W, with zero losses assumed in the rotor swirl or the generator.

I would say you’d be lucky to get 50 W from it on a good day. But don’t you worry, industrial designer Marcos Madia, I’m just a mechanical engineer with a fluids emphasis… what do I know?

5. Saki_Kawa on said:

Hello everyone!
Well done project.. but a vertical axis turbine with vertical pales coming out from main vertical tube could be more efficient and easier.. don’t you think so?

6. By the way this looks, it may be useful for independent film shoots, replacing gas powered generators when you’re shooting in remote areas.

7. So, for what it’s worth, I e-mailed the creator about the power rating. Here’s his response (translated from Spanish):

“Thanks for your interest. The wind turbine was a university project I did with a couple classmates. The power was estimated taking into account already existing projects. We don’t have concrete figures. In any case, it’s a completely conceptual design.

Marcos”