Re: [electricboats] Recommendations for a windmill/charge controller?

Sure, you can do it.  And it's free.  And it will give you power w/o sun.

However, 200watts from a 400watt AIRX is unrealistic.  Why?

Power scales with the cube of the windspeed and the 400watt rating is at 24kts as I recall.

P ~ 400*(kts/24)^3

So, for 200watts, you would need: kts = 24*(1/2)^ 1/3 = 19kts

And that's wind speed relative to the gennie of course.

I suppose if you expect to sail for 8hrs in 20-30kt winds the calculation works.

 

-MT

 

 

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of Ryan Sweet
Sent: Tuesday, March 7, 2023 6:39 PM
To: electricboats@groups.io
Subject: Re: [electricboats] Recommendations for a windmill/charge controller?

 

Thanks. I guess that gets back to my question: is it safe to run the windmills when you are underway?  Googling seems to indicate so?

 

All the installations I see it looks as if the entire thing is located well out of the way of crew or sheets or sails, but I'm wondering if there are other reasons that it's simply not a good idea?

 

Very Correct that you don't want an anchorage to be windy, but here in Washington it's not uncommon for evening atavatic winds to come down from the mountains and if you are anchored with the land windward it will blow across the boat but not create uncomfortable rocking near shore. 

 

But also, if on an eight hour sail I can keep a 400w turbine going at 50% capacity, that's 200w/48v * 8h = 33.3ah back into my battery. Only 1/24th my total capacity, but since I haven't been able to fit even 400w of solar panels in a non-shaded location (trouble with ketch rigs - I currently have two small 100w hanging off the stern rails) it's better than having to always find a marina to recharge. I tend to get less than half that power input out of prop regen if sailing above 4.5 kts or against the tidal current.  It might also exceed whatever motoring I had to do to get out of the marina or through a countervailing tide etc. I guess if I was always sailing north I could keep solar under the mainsail and it would mostly be well lit. :-). Super interested for the day when we can make sails out out flexible solar material, it will come. 

 

Range under battery is the reason I get anxious about taking this boat on longer trips like the inside passage. I have backups like nobody's business including a bunch of extra batteries, small solar generator, and gasoline generator, but that sort of defeats the point. maybe I should just add another 800ah worth of lithium but that's also another 1000lbs too. I'd have to put them in the bow somewhere to balance the boat. 

On Mar 7, 2023, at 18:03, Kev <captainyoung@gmail.com> wrote:



We had an airx. I would not recommend wind power.

Very noisy, only make power in 10 knots plus, and most anchorages are not windy. When it is windy they do make a good amount of power and noise.

Solar worked much better. 

Maybe if your in a location with little sun and lots of wind it could be useful. But in my experience in Florida and Bahamas,  solar worked very well. Wind was not needed.

I still have the tower/poles and hardware, if anyone is interested.

 

On Tue, Mar 7, 2023, 8:16 PM Ryan Sweet <ryan@ryansweet.org> wrote:

Yeah I'd be interested. I am not in a hurry but tell me more? 

On Mar 7, 2023, at 17:11, THOMAS VANDERMEULEN <tvinypsi@gmail.com> wrote:

I might be interested in your airex windmill.
Please message me with additional details, your asking price, and present location of the gear.
Fell free to email to tvinypsi@gmail.com.