Wednesday, December 21, 2011
"What Do Them Windmills Do?"
If you run across Swing Set out on the water, there is no mistaking her for another vessel if you notice the "windmills" sprouting from the top of the radar arch. Actually they are not windmills at all because, well, windmills mill grain by virtue of wind energy. (Think of those Dutch windmills you see in all those pictures at the art museum.) These are Air-X Marine Wind Generators, and they produce electricity to be stored in battery banks to be used as required by the various systems on board. This post is about how we arrived at this solution to the issue of providing power for long term living aboard "on the hook".
Wind generators have been in use on sailboats for years. The line on them is that are noisy, but as that may have applied to older models, new blade design has rendered the new generators to by very quiet, especially compared to the exhaust noise of a diesel generator. Once we decided upon living aboard and life on the hook, providing power without the constant aid of our Westerbeke diesel generator became one problem to solve. Naturally solar power comes to mind. I had considered having our local stainless steel fabricator, "Little John", make something like half of a T-top, coming off aft of the radar arch, which would provide room for one two foot by four foot solar panel. One panel of this size can provide 80 to 100 amp hours of electricity at its optimal output, the middle of the day with little clouds. One person suggested mounting panels above the bimini as we leave it up all of the time. There is room for three panels above the bimini, going that route we could claim 240-300 amp hours. Sounds like a lot, right? I'm no electrician, and I am in over my head here in some of the technical aspects of this application, but once you convert amps to watts, the numbers are not that impressive. Adding the extra weight to the bimini frame also seemed problematical.
I had been reading about the Air-X Marine units and although a fair amount of wind is required before you can even start making power, (It's 7 M.P.H.) if the wind is constant, power will be generated all day and all night. It adds up. At maximum output, which is a 28 M.P.H. wind, each Air-X unit provides 400 amp hours. No one really wants to spend much time at an anchorage in a 28 M.P.H. wind, but even as the power output is less as the wind is less, the bang for the buck is way better with wind generation for our situation.
One houseboat at a neighboring harbor has one of these Air-X units installed which initially gave me the idea to apply this concept to a powered vessel. The houseboat has the Air-X unit properly mounted on a pole, supported by guy wires. Some things that need to be considered when mounting something like this anywhere is that you need to keep them in an area where coming in contact with them with your head is avoided at all cost. Those carbon fiber blades would give you a haircut you would never forget. Height above the waterline is also an issue, particularly if you are considering doing "The Loop", which we are, and if there are any fixed bridges on your route anywhere. The T-top mounting method still seemed viable, and two Air-X units mounted on each side with one solar panel in the middle was considered.
When you attempt a project like this, it helps to have people involved who have done it before. No one in our area has installed a wind generator, at least no one that I had talked to.
I discussed the project with a few boatyard owners, and although all were willing, a chance meeting with the service manager of Bloch Marine at our local West Marine one afternoon turned out to be a fortunate coincidence. J.D. Schmid was involved with the local Marine Max dealership and when they left the area, John Bloch of Bloch Marine hired J.D. to oversee the service department of the boatyard that we primarily dealt with. We got to talking about our possibility of utilizing wind generators as a power source on Swing Set, along with combining a solar panel. Now, J.D. is one of the most enthusiastic people you will meet, and once he got to considering the project, I was even more sold on the idea. Fall was approaching, and over the winter was a good time for a project like this, and the fact that one of Bloch's best guys, Dave Ludwig, would be assigned as the electrician/installer, the deal was sealed.
Once I found the best deal on two Air-X Marine units (at Defender Marine) and they were shipped to me, the three of us got together and started to formulate a plan.