25 Oct Is a Wind Generator on a Sailboat Worth the Cost?
Like many others, we searched for this information before we started cruising. We get asked this question a lot, both online and on the dock, from new cruisers to seasoned vets. Everyone wants to know: is a wind generator on a sailboat is worth the cost.
First, we have to define “worth it.” We will do so in dollars, energy provided, performance, and noise and intrusion on our daily lives. Our model is an Eclectic Energy D400. We did not buy it, our boat came with it un-installed, and we installed it. We hope that this is just about as unbiased as we can be, no one gave us any products or money to write this article.
Straight away, in dollars per amp hour of charging provided, solar wins hands down over wind. We can say that as a fact without a double-blind peer-reviewed study on the matter. Our thought is before considering spending the money on wind power for their boat, they should maximize the solar power generation potential and their battery charge acceptance rate.
Once you are set in that department, now it is time to consider add ons such as wind generators, portable gasoline generators or diesel gen sets, or hydro generators to add supplementary power and charging capability when there is no or low sun.
Does the D400 Wind Generator Make a Lot of Noise?
It is quiet as a mouse! Although I am not quite sure how much noise a mouse makes, and I have not put a decibel meter in front of the D400, I can tell you that the noise it makes is comparable to the wind blowing through a sailboat’s rigging. Clanking halyards at the marina will be far more annoying than the D400. It is normally almost completely silent, however, at times it does make some faint whooshing sounds in higher speed shifty winds.
In comparison to other models we have heard aboard other boats, we can definitively say the D400 wins hands down in this department. It is not as quiet as solar, but we have found some other models that make it sound like you are living next to an airport or a subway station. From a sound perspective, our wind generator is worth it.
Does a Wind Generator Make Enough Power For Our Sailboat?
In its name, it claims it makes 400 watts of electricity. This means it is capable of producing about 33-35 amps of charging power. Sounds awesome, right? Well, wait just a moment.
The power curve on this beast is not linear, it is exponential (kind of, but not exactly, it illustrates the point). This means at low wind speeds, the wind generator makes very little power. In 5-10 knots of a variable gentle breeze in which the boat shifts at anchor, you will make just +/- 1 amp or so on and off. This isn’t even enough to steadily keep your interior LED lights on (You do have these already right? Saving power is much easier than generating power.), let alone charge your batteries.
For the average fair-weather cruising sailor that enjoys sailing on lighter days and tucks into the most protected anchorages possible, wind power may not make as much sense. Even in the trade winds of the BVIs, the high hills swirl the wind through anchorages which makes the power generated very intermittent.
Does a Wind Generator Make Enough Power to Run the Autopilot While Sailing?
Sometimes yes, and sometimes no. Our wind generator is located at the aft of the boat. This is the most popular position. We have seen some up on mizzen masts, which make a lot of sense (but this is also a lot of weight aloft). The bad part about this location is that it is in the draft of our sails, meaning it gets disturbed wind off of the back of the mainsail often.
We also try to use weather routing to sail off of the wind as much as possible. Sailing with the wind at your back lowers the apparent wind, which is what is used to power the D400. For example, if there is a 15-knot wind, and our boat is sailing into it at 5 knots, that will make a 20-knot apparent wind, which is great for wind power.
However, if we are sailing away from the same wind at 7 knots, that drops the wind speed to 13. Remember that exponential power curve?
Lastly, while sailing, we have found that large waves have a big effect on the D400. A wind generator seems to work best when it is solidly mounted and not moving. However mid-ocean, the boat is moving around in multiple axes. Every time this motion takes place, with every wave, the apparent wind on our generator changes, resulting in less efficiency.
It is helpful at night to supplement our power usage, but at least on our boat, it can not cover the fridge, freezer, lights, instruments, radar, and autopilot all at once, and we hope to never sail in so much apparent wind that it could. When sailing, we also run our autopilot almost 24 hours per day, as we rarely hand steer the boat. Only for fun or when extreme power conservation is needed.
Solar Panel Shading Issues on Our Sailboat
Other than adding to weight aloft, which is always a negative on a sailing yacht, the shading of solar panels is our wind generator’s major drawback. During most of the day, Windy (as we affectionately call her) shades at least one 50 amp solar panel and sometimes shades up to 4 at a time (or 200 watts worth).
Like the relationship of wind strength and wind power, the solar panels’ wattage varies based on the strength of the sun reaching them but are much more linear, except when partially shaded. The 50-watt panel being shaded could be costing us 4 amps at 12 volts. To make up the power lost it needs to be blowing over 15 knots consistently.
To make up for shading most of the 250 watts of flexible solar panels on our bimini, it would need to be blowing 27-28 knots, steadily, without shifts. Ask yourself how many times you are moored in a location where that is happening?
We may change our minds on this as we reach the higher latitudes of Argentina, Chile, and Patagonia. Even then though, we must be careful. A wind generator can be damaged in extremely high winds above 45 knots. Once again, we try to avoid these situations, but if a storm or very strong winds are forecasted it is a good idea to tie off your wind generator early.
Danger to Birds, Heads, Fingers, and Sails
One last word of caution before we conclude. The blades are extremely sharp and move very fast. They have been known to cut off fingers, kill birds, and slice open heads. It is a good idea to consider the mounting location of the wind generator very carefully. We have been on some boats where they are dangerously mounted. Keep in mind, you may not be tall enough, but what if a friend or neighbor comes on board? What if someone is falling and puts their arm up? What if you lose a halyard and it floats back behind the boat?
Is Our D-400 Wind Generator Worth the Cost on Our Sailboat?
We like our wind generator it as it was free to us. We have thought long and hard for our answer to the question, would we buy one for our boat?
To us, at least for now, the answer is probably not. Not because it is a bad product, or because of the noise. It is very well engineered and virtually silent with zero maintenance so far. We wouldn’t buy it based on the cost per amp-hour provided and the fact that it shades our solar panels, which on an average day in and day out, produce more power.
It is also complex to mount, takes up deck space, it is heavy, and requires drilling extra holes in the deck. Likely when it dies, we will not replace it, and sell its guts. We are keeping our mind open though, it may be a lifesaving lesson we have yet to learn in the canals and fjords of the deep south. We will update you then.
Which Wind Generator To Buy?
If we did have to choose a wind generator to buy for our sailboat, we would probably choose the D400 again. We are very happy with its silence. You can find out more about it here https://eclectic-energy.co.uk/products/d400-wind-generator/
If you want to see more wind generator options, here are some from Amazon.com. There are some really interesting configurations to explore. We have not used these, nor do we recommend them, but they are interesting to compare and we do get a little kickback when you buy something on amazon after clicking the links on our website. If you like our blog on and want to support our journey and content without it costing you extra, follow a link below before you do your amazon shopping 🙂