The Nozzle/Diffuser wind turbine

This is a step by step guide on how to build a wind turbine by maximizing the wind speed using a nozzle/diffuser approach.
This approach was considered through various testing and prototyping to try and increase the efficiency of the wind turbine.
NOTE****Test video at step six****

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Step 1: Materials

two buckets (bought from Tesco)
MDF(Medium Density Fibreboard)
safety blade/scalpel
handsaw
PVA Glue 'polyvinyl acetate'(any preferable adhesive)
electric handdrill
PVC pipe(poly-vinyl chloride)
coupling(preferably oldham coupling or any good chosen connection)
Generator
U-pol(or some kind of filler)
multimeter and variable resistor

mekennedy1313 says: Jan 1, 2013. 7:08 PM

To say efficiency was improved you would need to take measurements both with and without the shroud at the same windspeed. Did you do this?

rimpest says: Mar 29, 2012. 7:34 PM

You should try letting the tips of the blades to slightly touch the walls of the yellow thing between the two buckets, this will make the turbine way more efficient ;)

sjsquirrel says: Mar 3, 2012. 8:13 AM

Good instructable, and great idea.
Adding some notations to the photos to help illustrate the text, or indicate what is being pictured would make it a great instructable.

eslipak says: Mar 2, 2012. 2:05 AM

Im curious about wind speed vs power ? Also blades size? Thanks a lot.

stringstretcher says: Mar 2, 2012. 1:17 AM

I would bet that your hairy arms in the turbine housing are causing a considerable amount of drag... I don't think the hair is the problem :PYour hands take up what looks like a third of the volume of the housing. Perhaps supporting the generator with three spider wires, holding it centered and minimizing drag. I realize this is a first run. Looks great, good work! Lots to be learned from the model builders flying ducted fan jets, NASA stuff.

dropkick says: Mar 1, 2012. 8:39 PM

Cool!
I've been toying around with the idea of building a small wind turbine to keep up the power on a pair of 12 volt batteries. I don't need much power generated as the only draw on the batteries is for a camper trailer parked up on my land. So it's just lights, furnace fan, and the stove exhaust fan.
-I'm tired of pumping up my Coleman lantern (plus the smell, uneven light, and heat) so my main power draw is going to be from my reading at night (around 4 to 6 hours).

However I don't want to build a very large tower to get to the steady and stronger winds, as that leads me to other complications.

You've given me a new option. Thanks!!

- I wonder how it would work with a Savonius?

skylossobaka says: Mar 1, 2012. 11:26 AM

As with most 'power' generating systems, measuring voltage alone is woefully inadequate. Put a fat resistor across there and measure the voltage across that. THAT will be a usable energy measurement. Optimizing for voltage alone is not going to get you where you want to go.

thewindmills (author) in reply to skylossobakaMar 1, 2012. 2:03 PM

the voltage was measured using a resistance of 47 ohms and we got a 17volts but wedid also use a variable resistor

skylossobaka in reply to thewindmillsMar 1, 2012. 3:22 PM

First of all, commendation son actually using a resistor. Many people seem to think they can measure the efficacy of their homebuilt generators by using open voltage and no current flow at all!

Whats important is the amount of power produced.

Using a varistor is interesting, but you're going to need to instrument the setup further with an ammeter so you can tell how much current is flowing. Multiply the potential difference across your load in volts by the current in amps and you'll get the power in watts.

At 17 volts 47 ohms you're putting through 0.36 amps for a total of just over 6 watts.

I'd think your goal would be to make that power number higher - whether its higher amps at lower voltage or higher voltage at lower amps isn't particularly important (though there will be interesting side effects that will alter the portion of the energy you can use as the load at higher amp rates)

When you say that by tweaking you got the voltage to go higher you're being very vague. Perhaps you could discuss what tweaking you did, how the blades and/or load were modified, and how the *power* output was changed by your tweaking.

Robohotic says: Mar 1, 2012. 11:43 AM

Great Tutorial . A small turbine like this is only good for charging a cellphone. All that work for little output.

thewindmills (author) in reply to RobohoticMar 1, 2012. 2:08 PM

yeah you are right wind turbines dont usually produce much power as expected but finding ways to improve its efficiency was a fun challenge. and when built to a larger scale using proper materials this can really be of good use.