Big diy grid tied wind turbine
 

Prairie Turbines presents: Breezy 5.5 A Reliable 5500 Watt Homebuilt Wind Turbine Generator

If you have decent ave wind you could eliminate your electric bill altogether with one of these heavy duty asynchronous grid connected turbines. All you need is a few grand and lots of ambition :), or you can spend more and buy most of the parts premade and save the ambition for the tower and set-up. I'm a big fan of this design, no batteries and lots of power in lower winds. It makes 5.5 kw at 23 mph wind speed, and I thought I saw somewhere that it makes 3kw around 12 mph (not sure).

Wow - that's serious hardware!

This vid shows the scale pretty well:

YouTube - Tower raising.

I'm actually considering doing a 1/4 scale output version of this design. I thought about buying premade blades like in my other windpower post, but am not confident that they will perform well on a fixed speed turbine. Non of the sellers could provide the specs I needed to determine this. The prairie turbine guys have their rotor figured out for this application :thumbup:. The whole set-up can be scaled down, but there will be some trial and error in getting the blades properly scaled down for my generator. This extends to the gearbox ratio too. If I actually do this project i may use a temporary chain and sprocket type transmission until I get things right so I can more easily try different ratios.

I already have the motor generator and I've found a source for the pipe near my work for the tower. I can get a 42ft long pieces of 3" sch 40 steel, if I can figure out how to get it home. They will cut it for free so I can handle them, but it would be nice to keep it a single piece (although it will weigh over 320lbs).

I will need at least a bigger welder for construction, and a power planer for blade shaping too.

This is looking like the best DIY way for me. I predict, either way, there is some kind of wind turbine project in my near future :).

That sounds awesome. I'm anxious to see what comes of this.

Yeah, I'm digging up an old post, but...

They have the Breezy 10k now, the kit seems to sell for $7900. That'd be a steal for a 10kw turbine, so long as it worked as rated.

I've been fantasizing about getting one of these for a long time (long before I moved into this house; the annual wind speeds around here would warrant it), does anyone here have any experience with any of the breezy equipment?

Charlie

That web site says that at 15mph it puts out 3.6kw of electricity, now most people never see steady 15mph winds, a good wind site for most people is 12mph and if you have less then 11mph most people shouldn't bother, now I realize I sound like a nay sayer, but I've been around wind turbines all of my life and I like to see them work, I've also seen alot of them that don't work, I can't find a chart that shows it properly but it looks like there is almost 3 times the energy in the moving wind at 15mph then at 11mph, so if you have 11mph average wind speed at your site 60 feet or 90 feet up in the air your 5.5kw wind turbine kit will be putting out around 1.2kw if you are lucky, of course the real life output is dependent on alot more.
There was supposed to be a tour a while back of a guys place that appears to have a turbine like this but it never happened, I drive past it every once in a while and never have seen it spinning.

"and never have seen it spinning".. That sounds like it might have been installed in a bad location.


I found this..

How to Calculate Wind Loads From Wind Speeds | eHow.com

"Calculate the force exerted by the wind at your target speed by squaring the speed in miles per hour and multiplying the answer by .00256.

For a 30 mph wind the calculation would be

30 * 30 * .00256 = 2.304.

This is the amount of pressure, per square foot, a 30 mph wind exerts."


So, if we double the speed. 60 * 60 * .00256 = 9.216 per sq foot..

Instead of double the force (with x2 wind speed), we got almost 4 times the force.. :eek:

One of the reasons you get much better MPG driving at 30 instead of 60.. :)

As I understand it the energy in the wind is cubed with wind speed not squared, that is why if you look at the power output of turbines they give a 11mph output and a 12mph output and the 12mph tends to be around 3/4 more, one chart that I looked at gave the force on the top tip of the blade of a wind turbine that had around a 20' rotor at nearly twice the force as the bottom tip of the blade saw if it was on to short of a tower, this kind of imbalance tends to cause vibration and rip wind turbines appart.

KE=1/2*m*V² applies to wind, too. So, no to that portion of it, though power of course is a different story (a story about V^3, but the story becomes a tragedy when the overspeed brake engages).

The right place for a wind turbine is at the top of a 300' tower. Wind is faster and more constant up there.

Depending on who makes the tower it tends to be around a 120 foot tower gives you the highest output per dollar spent, but it really depends on who makes the tower and the style of tower.