Small VAWT finally perfected

GreenPowerManiac

Yes, after several attempts to get a good solid design, I've finally got it running good. Based on the PMA design with a vertical boom instead. I like that design much better than the horizontals. No weight imbalance issues or wind direction changes. Just good old fashioned power generation. We're looking at a couple amps per 15 mph wind and 18 volts. This type seems to spin slower, however, probably due to the diameter of the boom. More torque at startup yet slower overall speed I'm thinking. Another thing of beauty was that it did not need balancing. This seems to be harmonic with the airplane wing type blades. One side catches the wind and the opposite pushes while the sides slice the wind and it'll start up on an up or down draft too. Any comments or questions, please ask.

One other thing: The surrounding windmills will not disturb it's wind flow. Haven't seen it slow down for much anything besides lack of wind.

mike95490

Re: Small VAWT finally perfected

Brand or Plans ?

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icarus

Re: Small VAWT finally perfected

~30 watts at 15 mph?

T

russ

Re: Small VAWT finally perfected

All at the same time!

GreenPowerManiac

Re: Small VAWT finally perfected

Questions answered in order:

Brand or plans ? No specific brand. Permanent magnet alternator design. I guess the answer is plans. The mounting is the only difference here compared to the hawts.

Wattage estimate: 7 volts at 7mph and 12 volts at 12mph. Figuring around 1-2 amps at those speeds.

At higher winds, one blade seems to move its pitch and slow it down. Wonder if I could set up one blade on a retention spring...

Cariboocoot

Re: Small VAWT finally perfected

So when does production begin?

You know your homemade turbines work better than 90% of the commercial units!
Which curiously is typical and also the exact opposite of the same situation with solar panels!

Windsun

Re: Small VAWT finally perfected

GreenPowerManiac wrote: »

Wattage estimate: 7 volts at 7mph and 12 volts at 12mph. Figuring around 1-2 amps at those speeds. 100-200 watts ?

At higher winds, one blade seems to move its pitch and slow it down. Wonder if I could set up one blade on a retention spring...

12 volts @ 2 amps = 24 watts.

Have you actually measured the amps coming out?

Peter_V

Re: Small VAWT finally perfected

Windsun wrote: »

12 volts @ 2 amps = 24 watts.

Have you actually measured the amps coming out?

Of course that assumes that you are measuring voltage and current at the same time.

I can remember a few years back seeing some vendors selling PV panels and stating their rated power based on Voc x Isc

I've seen a couple homebrew wind turbine builders make the same mistake.

GreenPowerManiac

Re: Small VAWT finally perfected

Yes, that's right. I was thinking A/C. Never mind. There was a chart somewhere either on my site or on the net that had volts/amps measure for reference on the PMA.

Production ? Marc, don't you think we should wait awhile ? Hasn't been tested at very high winds and the elements will tell the true picture. Eventually I'll include this modification in my HAWT turbine plans. I have one more HAWT turbine already built in the garage, making a fifth one. Maybe it'll become a unit for a D/C electric fencer for my new chicken coop.

90% old proven technology used in 100% modern fashion. That's the way those big mega-watter white turbines are built, right ? The ones on wind farms ?

icarus

Re: Small VAWT finally perfected

The fundamental difference between large scale wind and small scale, is the size and speed. Lrge scale run at comparatively slow rpms, a d handle gusts with size.

Small units spin up fast, and are subjected to wild variations due to gusts, all leading to short hardware life.

T

GreenPowerManiac

Re: Small VAWT finally perfected

Gusts are not that noticeable in smaller versions other than speeding up and winding down. The only stresses are on the bearings and blades. Voltage/Amperage could flux greatly too.

New updates: Winds around 20mph are making the blades give off "Flopping" noises. They're made of folded and shaped galvanized duct sheet metal. It may be too thin for the centrifugal forces of rotation. We'll see if it holds up and/or move one of the blades so that it will cause a braking effect.