Anyone tested multiple small wind turbines together?

[jorjenzak]

I'm sure there are practical and physics reasons why this won't work....but rather than going bigger and bigger with turbines....has anyone messed around with building a bank of smaller turbines into a single frame (kinda like a solar panel is built with lots of individual pieces) and linked together to generate power?

Just a thought that occurred to me when thinking about how solar panels are put together and wondering why the same concept couldn't be used to build a panel of wind turbines.

If a smaller turbine takes less wind to turn and by combining 10 or more into a panel and linking them together would generate a multiple of power to make it practically useful......hmmmm.

Crazy stupid idear I'm sure.

Jordan

[boB]

I would think that this would work just fine, especially if they were all connected to a common battery bank.  Since the different turbines have diodes to make DC from AC, they should just combine just fine anyway. (I feel a song coming on there)...

That's my theory, and what it is too....  Like the theory of the Brontasorus, which is thin at one end, much-much bigger in the middle, and thin again at the other end.

boB

[ghurd]

Works for me, small scale.

As long as they are not in series.

Song?

"Oh meee, oh myyy little turbines play well togtherrrr.

Looks like I'll neeeed a bigger inverrrterrr".

(I'm going out for "Idol" next time)

At some point, bigger is cheaper.  And it isn't too big.

G-

[wooferhound]

The MotoWind ia a design like you are suggesting

http://www.fieldlines.com/story/2007/12/2/16495/6486

plus a coupla more links

http://www.fieldlines.com/story/2007/11/26/145942/85

http://www.fieldlines.com/story/2005/8/21/143719/803

[electronbaby]

i dont know about this idea (actually I do, its not a very efficient one).

Let me explain:

When an individual is investing in a small wind system (this could be that their building it themselves, or paying to have it engineered and installed), the money invested in the system, compared to how well it works is important. This is an important ratio to understand in the RE field. Most people call it "payback". Payback doesnt just have to do with money. It has to do with the amount of ENERGY it captures compared to how much ENERGY it took to produce the system.

It is common for people to confuse power and energy. It is not common however to get money confused. Usually money is important factor as well.

The multiple smaller turbines idea would take more energy to produce than one larger machine. I dont care how you look at it, it just does. Even if you got the materials for free, the work and energy put into building it will amount to more than it will take if you were to build one larger unit.  If you have to buy the materials, it becomes obvious.

Small turbines take MORE wind speed to move them. Their rotors sweep less area and therefore will not capture low winds efficiently. A large prop will however. You have to consider friction loss in all of the individual turbines, and the gaps in between their rotors, which is just wasted space because it serves no purpose. I suppose its similar to comparing it to the space between PV cells. Yeah they could put the cells up against each other, but the laminant on the back would not stick to the glass (and you probably would get some cell to cell arcing).

So to look at the big picture, many smaller turbines wired in parallel would probably make a functional system. It is not the most efficient way to do it as far as EROEI (energy return on energy invested) goes.

[JW1111]

You also have to consider the labor costs, shipping costs, or warranty lag time involved in having one large turbine raised, lowered, and serviced.  It is the burden of heavy equipment and involves labor input.  Where with several smaller turbines you can do it your self.  And if your one large turbine goes down, you are dead in the water. But with multiple machines you still have several others working if one needs service.  And around here most of the larger turbines spend much time in regulation so as not to destroy themselves in a heavy wind, while the little ones like mine are shining like a star.  IN addition, with several turbines, you can design each individual turbines' blades to take advantage of different wind speeds, so you have them functioning at full capacity at every possible wind speed.  With one turbine you are stuck with what you got.  It cost me $225 including tower to get 2 amps per turbine in 14 mph with a crappy motor.

[Flux]

Multiple small turbines are not going to be as efficient as one big one.

Within reason you can put forward some case for several smaller ones compared with a big one, but that is questionable when you start mounting them on a common tower.

When you start crowding together large numbers of them then it becomes very doubtful. The efficiency will be low and the mounting will be a mess and you start to have to seriously think about how to control them in high wind.

There have been attempts to use the little Marlec machines mounted like a tree on a common tower with turbines on the branches, but they all steer and act individually. Doing as you suggest is not going to catch on soon.

Flux

[Chagrin]

You forgot the Selsam dude.

www.selsam.com

[TomW]

Oh, if you visit Dougie be sure to bring your own grease.

This guy is a rippoff artist. More salesman than honest turbine producer.

I wonder why folks keep pimping his obvious outrageous turbine?

He was debunked long ago here but people still buy his hype.

Tom

[jmk]

 Smaller ones will take up more space, more money in towers, more in wiring, more in wire and all around losses, more maintenance, and more that can go wrong.  

[electrondady1]

bigger is always better

the only reason to consider multiple small mills is if it is impractical to build a large one .

so then the question becomes the method of combining there outputs.

[Norm]

 G.....? would I find you on Utube if I done a

search? (....like Ghurd Sings?) LOL !

[Dr Robert]

I am considering doing this, but it is important to consider several items. Suppose you would like to get 5KW of power.

If anything less than 5 KW is not acceptable, then multiple turbines is not a good option since you are multiplying the probability of a failure.

multiple turbines will be more expensive.

multiple turbines will probably generate more power

               you have 5  1 KW Turbines             you  have 1  5 KW Turbine

   If one fails  at least  you will get 4 KW    vs    a failure means 0 KW

   if no wind at two locations  you get 3 KW    vs    no wind = 0 KW

You need to have all the multiple turbines operating independently and in parallel.

The multiple turbines should be matched at least in voltage so that all energy resources can more easily operate in parallel and be interchangeable.

Establishing a priority of resource utilzation will result in the most realistic "Green"

If it is very important to at least get some power under any condition, consider:

     Use multiple turbines +  multiple Photo Voltaic Panels  

 +   power stored in Batteries, hydrogen, etc.

 +   the Grid.

 +   Gasolene powered Generator

Establish a priority of applications in case your energy availability does not match your  energy requirement.    

[wildbill hickup]

It seems as all are stuck on the idea from a HAWT point of view. What about 2 or more VAWT type Mills in a frame either driving a common generator or each driving it's own and then hooking all in parallel. You could even build several blades and mount them on a single shaft(similar to what Ed and others have done) then put several shafts in a framework and mount gen/alt to each shaft. Wish I could say I came up with the idea but there is an outfit in Massachusetts that produces them for commercial purposes. A scaled down version might work well for individual use. Windstuff Ed could chime in anytime now.

Just two cents from someone 10 cents short of a dollar!

Wildbill

[jmk]

 If you don't have wind then none of them are going to make power. The big one will always start to make power before any of the little ones, and will sometimes make power all day long while the little ones don't. Your thinking unrealistically when you say three out of five making 3 kw. Wind won't very like that unless you only have one good spot at the top of the hill and the others are in poor areas close to the ground. If that is the case then you would make way more with one big one. When a turbine that is rated at 1 kw it only makes about 50 watts most of the time. To say that even two out of the five are making 50 watts and the big one isn't making power isn't right either. The big one is the one that will be making the 50 watts when the others are trying to make cut in speed. There will be days that it would do that all day long, or at night when the wind winds down.

[electronbaby]

The problem with VAWT's is that it is hard to decrease the surface area in high wind. They dont furl. The Savonius designs have this problem. Some of the Darrius  designs dont, but still no furling. This causes problems when trying to group a bunch of them on a tall tower or multiple tall towers. The cost of multiple towers usually does not do this idea any justice and the wind loading on a single tower will probably bring the tower down in a storm. The HAWT design furls and therefore is the most popular design based on the fact it deals with these  scenarios rather nicely, and still continues to have a long, operational life.

However, if you place the VAWTs on short towers or on your roof, chances are that you will see very little wind anyway, so it appears to work well (to the untrained eye) as long as you dont really need any energy capture. Usually, turbulence (from being on a short tower) will cause the life of the machine to be shortened however.

[Usman]

Yes, there are pros & cons of it, but ground reality; 7 x 400w AirX turbines are easier to handle, fault tolerant and more productive than one 2.8 KW Whisper 500, and cost less, especially in a logictic manner and reducing downtime.

But a lot more noise! if they were all mounted close to each other.

But you need to come up with a cost-effective mounting of these multiple turbines.

Check the following link:

http://www.massmegawatts.com/

Hope that helps.

Usman.

[TomW]

Roy;

You seem to have forgot that VAWTs work perfectly well on the ground. Or in the box, I guess. No need for height is an often cited advantage.

Tom

[DanB]

1 turbine to suit your needs is likely the most cost effective solution.  Larger turbines (as flux has pointed out) tend to be more efficient - especially in low winds.  Towers are expensive - the labor - the materials - the land all have value.  Lots of short turbines on short towers will not yield the power of 1 good turbine of similar swept area on 1 good tower.

The only people out there I know of that are promoting the idea of lots of small wind turbines are the people who sell small wind turbines.  Look at any successful small wind installation and you'll see they usually have 1 turbine that suits their needs.  If its a decent turbine from a reputable company then down time should not be an issue (and if you're reallty worried about that get some PV and perhaps a diesel backup generator to get your through).

That said - I do know a few enthusiasts who do have multiple turbines, but usually they get one - then need a bit more and add another, or just get another because they're enthusiastic and have the land for it.  And these folks are not messing with tiny turbines like the air403 or such.

We just finished with a workshop at Mick Sagrillos place, he had 3 turbines although I expect 1 would've more than met his needs, and perhaps the redundancy explains why his Jacobs has been broken down for a while (it's an easy fix).  He had an old Jacobs 2kW machine, and skystream (Broken down) and a very impressive ARE 442 (10kW machine).  The shortest tower was 60' and its flat lands there.