Electrical power on a sailboat is critical. Everything from navigation lights, radios, wind instruments to refrigeration, even the anchor windlass requires electrical power. Most modern sailboats store their electrical power in one or more deep-cycle battery banks consisting of multiple batteries connected in a series.

Which eventually leads to a question of, “How to recharge the batteries?”

Unless the boat has a dedicated genset installed, sailboats frequently will run their diesel motors for a few hours each day to replenish the batteries. This however has several drawbacks. First, it is fairly inefficient operating a large diesel engine to power an alternator for the purpose of generating electricity. Second it quickly burns through the limited supply of fuel carried aboard.

When I bought my 43 foot sailboat True Love, it had a wind generator/turbine installed but wasn't generating much electricity. Upon close investigation I found that there were a number of factors contributing to this.

First: It had been installed without much thought given to the clear uninterrupted wind flow needed to produce anything more than a trickle of electricity.

Second: It had been mounted too low, which in addition to limiting the wind flow, turned the spinning blades into a considerable safety hazard.

Third: The electrical wiring was undersized for the Volts and Amps being generated.

Fortunately the folks at Southwest Windpower were terrific. They actually make a wide variety of wind turbines for marine environment and well as purpose-built residential and commercial units. Even though my wind turbine was one of their 1st generation older models, they stood behind their product 100% with  an outstanding 5 year warranty program. After confirming the serial number on the unit, they sent me all of the parts needed to completely rebuild my unit, postage pre-paid(!) as well as offering full technical support and advice. After rebuilding my wind turbine, installing a mount extension and the proper gauge wire all the way to the battery banks, the unit has been virtually maintenance and trouble free for the last 13 years.

My wind generator is always one of the first items asked about when visitors, or people walking down the dock stop by my boat.

Wind turbines, such as the one pictured here on my boat, are actually quite amazing. They begin to generate power in as little as 6 or 7 knots of wind. In approximately 15 knots of wind it will produce an amount of electricity that is roughly equal to the amount of energy being consumed by the boat underway. Peak power output is obtained in about 28 knots of wind, generating close to 30 amps.

Additionally mounting it the stern of the sailboat it acts like a wind-vane to help keep the bow of the boat pointing into the wind while at anchor. This is desirable for aiding air circulation because the forward hatch acts like a big wind scoop funneling the breeze down below.

The newer generations of the design are quieter in operation and even have a built-in circuit board that monitors battery charge level. If it detects that the batteries are fully charged, it will actually spin itself down and shut-off automatically. It will continue to monitor the batteries and as soon as it detects a drop in voltage it will spin itself up and begin charging again. The construction and design is completely first class and the cast aluminum unit is designed so that it can be fully recycled at the end of it's useful life.

Anyone considering generating their own power is strongly encouraged to thoroughly investigate these wind turbines. The cost is fairly reasonable at around $800 for the unit itself and you will probably spend another $200 or so on mounting hardware and electrical wiring depending on distances involved.

 

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