Vertical axis wind generator?

[SV__Grace]

Our Airx is toast and considering replacing with a vertical axis wind generator. I've seen a few on other boats and they seem to have some advantages but they're definitely not mainstream or carried by the large marine suppliers.

Any advice or recommendations?

[Bill O]

From my previous research, the verticals were not as efficient as the horizontal axis gens.
That said, would attempt to fit more solar than replace our wind gen for better energy return per $ spent.

[wholybee]

I have seen one vertical wind generator on a boat. When I asked about it, I was told it was useless, and he only left it there because it was a conversation starter, and other cruisers would introduce themselves to ask about it.

[Ryban]

Agree with above, my understanding is that they are definitely not nearly as efficient and the more common wind mill type. They might make sense in backyard installs where their lower noise profile is more desirable than their power output.

I'm also of the opinion of put as much solar on your boat as you can before adding wind.

[GordMay]

Vertical Axis Wind Turbines (Darius & Savonius Rotors) would be a structural* & aerodynamic nightmare on a sailboat, and are inherently less efficient**, than Horizontal Axis Wind Turbines

* Require strong support, & bearings, at both upper & lower ends.

** A VAWT puts out about about 30% of a comparable HAWT.

“Wind Energy Systems” ~ by Gary L. Johnson
Download or read it online for free ➥ https://www.rpc.com.au/information/f...y-systems.html

See Chapter 4, “WIND TURBINE POWER, ENERGY, AND TORQUE”
➥ https://www.rpc.com.au/pdf/wind4.pdf


There's several older CF discussions, of vertical axis wind turbines, all coming to the same conclusion*: HAWT aren't practical, on boats.
* With as much, or more, consensus as CF discussions ever produce.

[SV__Grace]

Thank you for the links Gord, very helpful. I was hoping VAWT have evolved in the years since previous discussions, but maybe not?

Originally Posted by GordMay

Vertical Axis Wind Turbines (Darius & Savonius Rotors) would be a structural* & aerodynamic nightmare on a sailboat, and are inherently less efficient**, than Horizontal Axis Wind Turbines

* Require strong support, & bearings, at both upper & lower ends.

** A VAWT puts out about about 30% of a comparable HAWT.

“Wind Energy Systems” ~ by Gary L. Johnson
Download or read it online for free ➥ https://www.rpc.com.au/information/f...y-systems.html

See Chapter 4, “WIND TURBINE POWER, ENERGY, AND TORQUE”
➥ https://www.rpc.com.au/pdf/wind4.pdf


There's several older CF discussions, of vertical axis wind turbines, all coming to the same conclusion*: HAWT aren't practical, on boats.
* With as much, or more, consensus as CF discussions ever produce.

[dlj]

Back when I did work in off-grid living, the Darius & Savonius Rotors were only a viable option when you had like a mountain range where there were thermals that had a fairly consistent updraft and a location for those wind generators to capture that air movement. I think in all the work we did, there ended up only one location where we seriously considered putting one in, and we didn't because of the high cost to output ratio. As far as I can tell, those systems pretty much never work out to be cost effective. Today with the current price and output of solar panels, it's even less likely they would be a serious option for power.

dj

[Cloroxbottle]

I'm considering adding a pair of these wired in parallel:

https://www.leadingedgepower.com/pro...-1013843.html#

There are two options:

(A) A pair of 48V turbines to charge the engine (power supply for Elco engines) bank which in turn charges the smaller house bank through a DC-DC 48V-12V

(B) A pair of 12V turbines to charge the house bank directly, bypassing the engine bank.

I can see advantages to both.

With setup (B), on a cloudy/windy day at anchor you would be replenishing the house bank directly...or under sail/at night without the efficiency loss of the step down.

Withe setup (A) under the same weather conditions you'd be "topping off your gas tank".

Thoughts?

[Opie91]

That seems like a lot of work for not many watts. Less than 10 watts at 22mph, not good.

[TrentePieds]

The kinetic energy contained in a wind of given velocity must necessarily stand in ratio to the area of the capturing device that you can expose to the wind in a plane normal to its direction.

That is why Savonius rotors can never be big enough on a sailboat to capture enough energy at NORMAL wind velocities to be worthwhile. On land their support structure become rapidly more cumbersome as the rotor dimensions are increased. They just aren't worth the candle, so to speak.

Horizontal axis turbines are far more useful, in part their technology runs in parallel with aircraft technology in so many ways, i.e. their "problems" were solved a hundred years ago in the interests of "getting one up" on enemies in future wars. But even so, their dimensions, to capture worthwhile energy quickly become unmanageable on a sailboat.

Stick to solar power and frugality for "house uses" and the engine mounted alternator for starting and driving such thins as the capstan.

TrentePieds

[skipperpete]

There’s a monohull just across from me in the marina that has a vertical axis wind turbine and it doesnt seem to have a special high strength mounting, just a pole like any of the usual horizontal axis ones. I have no way to find out how much power it generates but its rarely not spinning, when all the aerogens etc are at rest, that vawt is still quietly spinning.... and I do mean quietly. Even in a recent blow with gusts registering at 35 knots it made no discernible noise but the 5 conventional wind generators on our dock could clearly be heard above the sound of the wind in the rigging.

[Cloroxbottle]

I appreciate all the input, but with an electric conversion, I don't intend to leave a single watt unharvested. So given that, would it be better to have the wind generators at 48V charging the engine bank, or 12V charging the house bank?

[SailingHarmonie]

Originally Posted by Cloroxbottle

I appreciate all the input, but with an electric conversion, I don't intend to leave a single watt unharvested. So given that, would it be better to have the wind generators at 48V charging the engine bank, or 12V charging the house bank?

You came seeking recommendations and advice. In very unusual situation, the recommendations you got were pretty much unanimous: It's a waste of money to do what you propose.

You now say you are going to do it anyway.

So, just do what you are going to do and stop asking for other people to justify what you think is right, contrary to all available data. I am sure that there is somewhere on the internet you can find someone who will agree with you. Just like if you say the sky is pink not blue.