Wind Generator Performance and Ratings confusing for a Sailboat?

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Wind Generator Performance and Ratings confusing for a Sailboat?Many years ago it was easy to find all the detailed specifications (like wattage) on the small wind generators. Over the last couple of years manufacturers have moved away from publishing actual wattage rating of the wind generator to now showing performance curves on a monthly or annual basis (A-Hrs or kW-Hrs, over time).

This is confusing and has irritated many! Limiting the average buyer from making an “apples for apples” comparison during the purchasing process. The reality is that the wattage rating of the wind generator does not really truly reflect its ability to produce energy, which is what most buyers are looking for. Energy production over time should be the true benchmark for making a decision which one to purchase.

Smaller wind generators (lower wattage) will usually start-up in lighter winds being able to produce energy effectively below 15 mph. On the other hand, larger rated wind turbines (higher wattage) are typically heavier and have a larger wind sweep diameter (this makes sense in order to capture the energy from the wind). They will typically not perform well in light winds therefore capturing little or none of the energy that’s available. In high wind conditions (typically above 15 mph) they perform very good.

Bottom line, the energy produced depends on the typical or average wind that the generator is exposed to. So over a period of time, let’s say a month, a smaller wind generator sitting in light winds will typically outperform the energy production of larger wind generators. Of course the converse is also true, it also depends upon the design of the wind generator and therefore it would be prudent to see and energy production curve at various wind speeds to find out who is the true performer.

In simple terms, selection of which wind turbine to purchase should be based on the anticipated winds one expects to be sailing & mooring in and not on its wattage (instantaneous power) rating. (Read How to determine if a wind turbine is a good choice for me?)

Also don’t be fooled by the wind turbines that seemingly spin in light winds, they are just turning (like a garden wind ornament) and not producing much in the form of power, if any at all.


1 comment(s)
Tony March 6, 2015 9:31 AM reply

Great commentary but little answer. You suggest a comparison leaving us to expect what you guys are seeing in the trade and showing a comparison. Having owned an AirMarine 40A back when they first came out and using it for some time including 3 yrs trip to the Med and back through the islands, I appreciate this topic. Now we're no longer talking in Amp/Hrs but KW's, which is very confusing. In the end of the day, a boater wants to know how many a/h's he's getting back into his system. I totally agree with your comment about higher vs lower rated systems, hence I bought the new Air Breeze unit to register more power over the 24 hr rated period. I believe too, in the end, I'll get more power as it will be generating energy in an anchorage more efficiently than the 40 a/h unit.


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