What is the best for your Boat?

A wind generator or a solar panel is a safety backup. If your engine is disabled or you have an outboard without charging ability and your batteries run down, at least you have power to run a radio or other instruments. After a few hours, you may have enough charge to start the engine. 

About Wind Energy for Yachts

On gusty days, a wind turbine put out a lot of power. The power available from the wind varies as the cube of the wind speed. If the wind speed doubles, the power of the wind (the ability to do work) increases 8 times. For example, a 10 mph wind has 1/8th the power of a 20 mph wind (10 x 10 x 10 = 1000 versus 20 x 20 x 20 = 8000). One of the effects of the cube rule is that a location that has an average wind speed reflecting wide swings from low to high velocity may have twice or more energy potential of a location with the same average wind speed which varies very little. This is because the occasional gusts pack a lot of power in a short period of time.

You also have to consider where you anchor your boat. We all try to anchor in a lee and get out of the most wind.

Wind Generators about 1100 to 1800 Euro

• Routine maintenance required
• Auto switch Off in strong Winds

Typical output: 3,6Kw per Day

At 15-20 knots 100-250 watts

About Solar Energy for Yachts

The available space to mount solar panels is also quite limited on a sailboat. The most common ways to mount solar panels is above the bimini, on a stern rail, above dingy davits, on a pole mount, or on an arch.

The positives on solar panels are that solar panels require little maintenance, last 25 years or longer and are completely safe. There is no noise factor to contend with and panels can stay out in practically any weather. The output production warranty is typically 25 years.

Solar panels, including charge controller and mounting hardware, are generally less expensive than a wind generator. 

Solarsystems about 400 to 1200 Euro

• No routine maintenance required
• Low - no moving parts

Typical output 1,8kw Per Day

6.5 Sun hours = 280 watt hours

Don't Forget, its can save your Life!

The best alternative is a blended system with both a wind generator and a solar panel. When in the Azores earlier this year, we had five cloudy days with little direct sun but the wind blew 15 to 20 knots. Those cruisers with wind generators were able to keep their batteries charged, but those with only solar panels had to run their engine to charge the batteries. Later, we had days where the wind was very light and the days were very sunny. Having both would protect your independence from having to continually charge your batteries by running your engine.