Solar Panels: Are they useful equipment?

solar panels island spirit catamaranSolar Panels come in all sizes and shapes and are used on boats more often as an extra source of energy. Solar panels convert the sun's incoming radiation (light) directly into electricity, which can be used to charge batteries and operate DC loads. It's becoming more popular among sailors not only because they can keep lights and appliances running, but also because they are quieter than wind generators. The source of energy is also free and abundant. We have had solar panels on the last two cruising catamarans that we have owned and thus have first hand experience.


On our Island Spirit we had solar panels and a wind generator and found that we could easily have done without the wind generator. What we found with the wind generator was that it was niosy and because it had moving parts required maintenance. The advantage with the wind generator is that it works 24 hours a day versus the solar which only works when the sun is shining. While underway it is nice to have the additional power from the wind generator but again there is a constant noise which quite frankly we could do without.

Modern electronics such as auto pilots and LED lights have become very energy efficient which means that the drain on batteries is not as great, and the solar panels can easily keep up with the demand especially when combined with an hour of engine generation per day. Our current boat has no wind generator and two 230W solar panels with an additional house batter. We find that this setup works well while sailing offshore as well as cruising lacally. In my opinion the more energy generation we can fit on the boat that is in solid state and requires no maintenance the better.

There are several applications for solar energy on yachts:

  • Yachts with no access to shore power, need to keep their batteries topped off. 
  • Cruising yachts use it to augment charging options.  
  • Boats without auxiliary engines may use solar power for all onboard uses.

Tips on what to look for in solar panels: 

When selecting a solar panel, there are several important questions you should ask yourself

  • Is it necessary for the panel to be flexible? The thin film panels are the only ones that flex more than a little. They can be mounted on curved surfaces like a dodger. 
  • What is the cost per watt of output of the panel? Large “hard panels generally have the greatest output per dollar.
  • Are you limited in the area available for solar panel coverage? The highest efficiency panels are the monocrystalline type.
  • Will it be difficult to protect the panel from partial shading during the day? Thin film panels are more tolerant of shading.
  • Will the panel be used in high temperatures? If so, consider a higher voltage panel, or a thin film.
  • How much energy will you need - match your marine electrical needs to the right size panels and battery

This article "charging with solar panels" in West Marine is excellent.

Contact us for  more information on solar panels.


0 # Marta De Wulf 2017-06-15 08:45
Curious your thoughts on after market vs factory installation of panels. My initial thought is we can get higher quality at a better or same price. Thank you for the above things to consider, it was helpful.
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0 # Catamaran Guru 2017-06-15 12:12
Hi Marta, in my experience the factory supplied panels are not that good so aftermarket you will be be able to get higher capacity and quality panels at a similar price. Note if you have to have a custom bracket to mount the solar array this could push the price a bit higher but worth it.
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