Not buying it!
I have had my anchored boat forced to port when my port mounted turbine kicked in.
You may point higher into the wind with a turbine connected to a screw but you will never point into the wind and make headway. One of the discussions on this list many a time, is what kind of power will be required to overcome the windage of our boats. You are talking about adding wind catchers to your boat design.
I do like the idea of help to keep the boat in place when serious weather comes along, so even if you are feeding the diesel to have a fighting chance that is a good option.
A wise sailor removes the rigging when he is facing a hurricane, and moves his boat where wind is least likely... The reason? Even the wind against the standing rigging can mean disaster as wind has it's way with the boat. Put another way, "For every action there is an equal and opposite reaction." I have experienced this many times on the boat. I have dragged anchor many a time because I wasn't in good holding ground, and the wind had it's way with me. Had I not had that extra wind drag called a wind turbine, I may have been able to hold my position.
Many of the old water pump turbines like those shown on that site lost their lives in heavy blows because they were not turned out of the wind. What will you do with a vertical with so many blades in a heavy blow? All things made by man are compromise, and wind turbines are no different.
I downloaded their "science behind" brochure. I found magnetic bearings that were not really magnetic bearings. All magnetic bearings I have seen required a controller to do their job. Cogging only quiets the generator down at startup, and allows lower speed startups, but no other advantage I can see.
Summary:
If every action has an equal and opposite reaction. Then 10 lbs of thrust against the hull in the form of wind will have to be overcome with 10 lbs of thrust against the hull from the other direction. Because we are using thrusters or other drive means to do this, we must consider the losses involved with the drive. Typically we are looking to at best 60% of what goes into the drive making it to moving the boat. We must now consider losses in battery charge and discharge. This is still much better than with an ICE but must be considered. We must then consider the efficiency of the generator system. The reason that a motor must be turned above the speed that it runs at a set voltage to produce power of that set voltage, is losses in the equipment. Now 100% of the power in the wind is not converted to motion in the turbine, and 100% of the power in the motion of the turbine is not converted in the generator to electricity. We must now consider the diode loss to convert the power from the AC generator to DC.
My guess is 80 to 90% of the power needed to keep the boat stationary will have to come from an ICE driven generator and I think that is conservative. I found it difficult to keep my autopilot running on what my wind generator would produce, and that was pretty much passive control, go figure.
Sorry if this is a little harsh, but I would not want you to spend everything you have to make a system that will not work, because nature is even more harsh than I. We just must live within the laws of nature, no choice.
Kevin Pemberton
On 11/09/2010 08:12 PM, Steamboat Willie wrote:
I can only wonder what one of those would do on the racing circuit!!!
For the rest of us, rags are probably cheaper.
Willie
--- On Tue, 11/9/10, Kerry Thomas <kjthomas@ihug.co.nz> wrote:
From: Kerry Thomas <kjthomas@ihug.co.nz>
Subject: RE: [Electric Boats] Station keeping Azipod -- was Re: Multidirectional Docking Electric Motors
To: electricboats@yahoogroups.com
Date: Tuesday, November 9, 2010, 9:17 PM
Hi There was a catamaran here some years ago. Whangarei NZ. With a propeller turbine directly coupled to the prop that could go to windward. Also a similar setup in wooden boat magazine, on a monohull.
| Bear in mind that wind turbines have a LOT of wind resistance (you don't get the power for free) and it will take more power to hold the vessel in position with them running. But there has been an idea kicking around for the past 20-30 years, and that's to have a wind turbine connected to a propeller and drive a boat DIRECTLY UPWIND... You might be the first!!!
Willie
--- On Tue, 11/9/10, Galstaf <richard@atlrent.com> wrote:
From: Galstaf <richard@atlrent.com>
Subject: [Electric Boats] Station keeping Azipod -- was Re: Multidirectional Docking Electric Motors
To: electricboats@yahoogroups.com
Date: Tuesday, November 9, 2010, 10:32 AM
To clarify: I am indeed seeking an anchorless solution, and this is going to be a *non sailing craft* with 15-20kW of vertical wind turbines. More turbines may be added later.. they are not nearly as large or heavy as I had originally anticipated.
The Azipod does pretty much what I am looking for; I just wasn't aware of the name. Ideally I would like that to be the principle drive for the boat also.
Can anyone recommend a manufacturer for boats in the 50' (25000 pounds) range?
Is anyone using anything like this?
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