Energy? Create it with the wind. Roberto Minoia tells us the secrets of the wind generator

Harnessing wind to produce electricity would seem the easiest thing to do for those of us who are already used to using wind power as a powertrain. Wind has been the most widely used form of energy since the earliest times, and ultimately, if you think about it, it too is a byproduct of solar energy. Turning wind into electricity requires an alternator (yes, just like the one in the engine) that is rotated by a wind-driven blade. Apparently very simple, right? There are many wind generators on the market, but they are not all the same. Alongside models worth a few hundred euros, we find others well over a thousand euros. The differences are there, and they are not few. What should be considered before buying a wind turbine?

THE MAXIMUM POWER
Certainly one of the first characteristics that must be evaluated is the power generated. it is quite obvious that a 100-watt wind turbine will have very different performance than a 400-watt wind turbine. But maximum power is not everything. In fact, we also need to see how many knots of wind are needed to develop that power.

THE MINIMUM WIND SPEED REQUIRED TO PRODUCE ENERGY
You often see wind turbines running very fast in 8 knots of wind or less. Do not be misled, because they are probably not producing energy at all with that wind intensity. Many wind generators need at least a dozen knots of wind to begin producing a few tenths of an ampere, and since we cannot always count on winds of 20 knots or more, it is very important to evaluate in the selection those generators that begin to produce energy already with winds of less than 8-10 knots.

THE POWER CURVE
The graph showing the power generated by wind power as a function of wind intensity is called the power curve. is very useful information in that by comparing the curves of different products, we will prefer those that “soar” faster than those that rise very smoothly.

THE SILENCE OF THE GENERATOR
You have surely happened to be in a beautiful roadstead in the evening and hear the very tedious whistle of the wind from the boat a few dozen meters away from you. If that hissing annoys you who are discreetly far away, imagine those poor occupants who are no more than 3-4 meters away from the blades. Quietness is therefore an element that should not be overlooked. Today there are excellent products, with carbon blades designed in the wind tunnel, that manage to keep noise within very acceptable limits. During last November’s Atlantic crossing, our boat was equipped with one of these silent generators, and I must say that even in winds over 25-30 knots, the noise was virtually unnoticeable. If you are considering purchasing a wind generator, first consider where you usually sail. If you sail in the Gulf of Genoa in August, you’re probably better off giving up and installing efficient solar panels instead. If, on the other hand, you plan to do the Aegean, then a wind turbine can give you great satisfaction in on-board power management. Try it to believe.

WHO ROBERTO MINOIA IS
Roberto Minoia is in the software design business in life, but as soon as he can, he devotes himself to sailing in the Tyrrhenian Sea aboard his Dehler 41 CR. His passion for sailing and technology, combined with a penchant for popularization led, in 2008, to the birth of the Blog Della Vela (www.blogdellavela.it) where, consistent with his free time, he writes technical articles, reviews boating products that he himself uses, and publishes diaries of his sailings.