Another one ticked off the list, and a big one. You see, the wind turbine is a benchmark for the charging system on Satori. It solves the biggest problem I have with living on a boat. It’s having enough power to allow a slightly bigger level of comfort. I have a backup generator in case I need to run a high-amperage AC appliance or in case the solar and wind components fail, but I don’t like to use it. It’s loud, it exhausts carbon monoxide, and it uses highly flammable gasoline to run. I will only keep a few gallons of gasoline on board for emergencies and to run the outboard for the tender. Satori should be able to keep up with the demand of her crew and supply electricity for navigation instruments, refrigeration, computers, gadgets, lights, and so on. So now she does, and I’m a happy sailor.
Perhaps the most challenging part of boat refits are getting it right the first time. I’m getting used to these projects, and feel like I’m getting better at making decisions. To get a wind generator installed, I needed a mast. To install a mast, I needed to modify the stern pulpit so it worked with the wind vane and supports the turbine mast. Before going any further I needed to figure out the circuit for providing a constant load, and proper circuit protection. Not exactly a simple circuit. There is a blocking diode involved to prevent the other charging components from feeding into the diversion circuit. The concept is slightly counter intuitive for me because I have always thought of a charge controller as a way to provide voltage to the batteries, controlled by monitoring the battery voltage and then shutting off once the charging is completed. That does not work with a wind turbine because it needs a constant load at all times. Fortunately someone has inventoried the entire boat circuit and determined the best component to keep under load. With an AC circuit, the hot water heater element is powered to a full 500 watts until the thermostat’s maximum temperature is achieved, then turned off until the temperature drops to the minimum set temperature, then cycled back on again to keep the water heated at a constant temperature. When you use 12 volt to heat the water, it can heat to 500 watts, but that would be a load equivalent of 41 amps. The turbine charging system takes the AC/DC heating element as the diversion load and dumps any excess energy after the batteries are charged to heat hot water. Unless I am not using any electricity, there is little chance of the hot water ever being heated to beyond 110 degrees. That would require thirty knots of wind blowing for a few hours to achieve such a temperature. To achieve the maximum hot water temperature that the plumbing system can handle, it would need to remain constant for up to eight hours or more. The maximum temperature for the hot water tank and PEX tubing is two-hundred degrees, which likely takes more energy than the charging system could ever achieve.
When researching wind turbines, I noticed a big difference between each unit. Output, quality, durability, and noise levels were all something to consider. I began with the only unbiased test that I believe has ever been documented on the internet. After spending some time researching prices, I decided to call Hotwire Enterprises to ask some questions about their KISS turbine. Before I had even made a decision, I had discovered that Dave had a few units sitting around his shop that he was planning on selling for much cheaper than the normal retail price. He offered half the price for a used unit but included the same warranty as his new units. Given their popularity and perhaps the best customer service and technical advice, I decided to go for it.
I had them send me the charge controller and diode first so I could get it installed and ready to run. The diversion load controller they offered was basically the same as my existing solar controller, except that the load rating is only 45 amps instead of 60 amps. I honestly think they are almost identical. Fortunately I had already learned how to program the unit with custom voltage settings, so I just needed to track down the serial cable I used for the solar controller. I first had to solder one of the wires back onto the serial plug after seeing that it broke off. Once I had my Macbook booted to Windows and the Morningstar software loaded, I was able to set the DIP switches on the unit and then turn the unit on by wiring it to the negative and positive bus bars. After setting the controller using the software, it was ready to accept any extra voltage that the battery did not need after being fully charged. I then only needed to install the heating element and then work on the turbine circuit separately.
A couple of days later the turbine was delivered with everything I needed to install the unit, minus the support struts and fuse. I bought the additional parts Fisheries Supply and began assembling the unit. The first step was just fitting the unit with the blades installed to make sure that the backstay did not interfere with the turbine blades. There was a clearance of about five inches, which was perfectly acceptable. The next step was to get the support struts installed and make sure the turbine was supported properly. I was lucky that the six-foot poles fit perfectly without having to do any cutting. Not only that but they were lined up with the bimini support struts, which created a solid support structure. The next issue was figuring out how the PVC parts fit together. There were instructions that came along with the unit, but I still had a difficult time figuring it out. Finally after reviewing how they fit together and were secured to the mast, I had a plan to make the final install. I only needed to drill a couple of holes through the PVC insert and stainless pipe. At first the set screws interfered with the contact slip rings, which allows the unit to spin in circles without having to worry about resetting after too many revolutions. Then the set screws interfered with the turbine housing. After some jiggery-pokery I had the unit installed without the blades attached. The next step was getting the unit wired to the positive and negative buses. I had some Triplex ten-gauge wire left over from my winter project that allowed me to run the wire through the deck-to-hull joint and then finally to the control box. Another Duplex ten-gauge wire went to the positive and negative buses, through a forty-amp terminal fuse. Finally, I installed the blades being careful to smother the bolt threads in Lanacote to prevent corrosion from the stainless bolts and alloy spindle indifference. It just so happened that the winds were just starting to pick up and within fifteen minutes I was watching the turbine spin, generating a few amps of electricity!
So far I have determined a few things, just from the short period of wind; First, the unit needs about twelve knots of wind just to get turning. Once it’s spinning, it needs a constant ten knots with an occasional gust to twelve to keep it going. The unit begins generating approximately two amps, then increases as the winds pick up. Once at fifteen knots, I could see five amps of charge on the battery monitor. The unit is perfectly quiet. Not silent, but also not loud enough to care. Even my dock neighbor commented on how quiet the unit was, considering how much it was spinning. I related it to the same as a household ceiling fan. Because there are no friction parts (like in an automotive alternator), there is only the sound of the fan blades cutting into the wind, and the vibration of the pole from the vibration that the unit causes. The vibration could be dampened a little, but seems insignificant to me. As far as I’m concerned, the turbine is going to work out nicely. I am not certain that it will keep up with my demand for electricity, but only time will tell. At the dock it is difficult to tell because I’m in a wind protected location, with a thousand masts between Satori and the open water. While sailing I imagine that it will be spinning at all times. While motoring, it will not make any difference. While at anchor, I will have a combination of solar and wind to keep the batteries charged. I really doubt I will have to use gasoline to charge the batteries. Perhaps to travel between anchorages in the San Juan Islands, but even that does not matter. I’ve got bigger plans.