build 1 larger diameter machine

[Joe Electric]

Hey guys, Great Website! Plan on building a wind turbine myself in the near future. However I ran across a posting (dumb question) about building 1 larger diameter machine wind turbine with 4x the power. My question is how exactly do you accomplish
this using the same materials? Would you just increase the wire size in the
coils (if so what size wire?), as well as increasing the stator and rotor in
diameter.

Thanks for your time.

[Jimmy D]

Hello Joe, welcome,

Before you get blasted I'd advise you start reading on this site. I strongly advise getting Hughs book or the new one from the Dans click on "our products" at the top. While you wait READ here, there are many variables to consider. While designing is encouraged you should probably start with a known design. It's complicated enough to keep you amused while you dream up your own scheme and the beauty of it is, if you've been skillfull, it works.

Best of luck, Jim

[Joe Electric]

3rd year electrician.  Never really considered wind turbine systems or any other until I started getting some questions from some of our service customers.  Have been reaching wind turbines for months.  Found this info here under (multi stator wind generator - If you build two machines on the same shaft - 4 magnet rotors, 2 stators, you get twice the power as one.  If you build 1 larger diameter machine with the same materials you get 4x the power as one.) Was just wondering how?  Thank you.

[SparWeb]

I think I can see what you're asking about.

The power you get from the wind is the power that you can "catch" in the blades.  If the blades are longer, then there is more swept area that is catching power from the wind.  Since you get 4x the area for 2x the blade diameter, that's probably what you've heard about.

Once you dive into the details, you'll find out that all the pieces have to be matched up to each other for the whole system to work.  If the blades are a certain size, then they will collect a certain amount of power.  The electrical generator must be able to take full advantage of that, otherwise the blades rip it apart.  If you go too far the other way, such as put tiny blades on a whopping generator, then nothing happens at all, they can't get it to turn over.

Then there is the tower, which must be strong enough for the size of windmill mounted on it, yet not so large that it's too heavy or expensive.  The rest of the electrical system is yet another project in and of itself, and requires some labour to maintain.

You know how all those flower-power people say you have to be in "balance"?  Well so do the engineers...

Welcome to the site, and enjoy your reading.  Please ask questions any time you have trouble finding answers, and especially if you get confused about something.  It's bound to happen.

[Flux]

Yes that's true. If you take the magnets and copper of a single alternator and build a duplicate you get double the power. If you put the extra magnets on a larger rotor you do better. Voltage depends on the flux per pole ( stays constant if you use identical magnets and air gap), frequency and number of turns per phase. Doubling the number of poles will double frequency and doubling the number of coils will double the number of turns per phase. You get 4 times the voltage.  For the same voltage you can use 1/4 the number of turns, with 4 times csa wire. Allowing for the doubling of number of turns you still end up with 1/8 of the resistance compared with halving it with 2 alternators in parallel. A very big improvement.

Flux

[Joe Electric]

Thank you Flux.  Your answer was exactly what I was thinking.