banner6a.jpg (17058 bytes)

Printer Version
6.5 in (17.1 cm) wide


Solar Panel on Stays  Solar Panels On Awning  Wind Turbine 
  Electric Boat  

For Boat Manufacturers:

There are some boat manufacturers who produce electric powered boats and even a few that produce solar powered boats. But the most common use of solar power on boats is as a charging source for storage batteries. This is also true for the use of wind turbines.  More often than not these are added later by the boat owner and are particularly popular with cruising sailboats as a means to keep the batteries charged without having to run the main engine or a generator.

As a boat manufacturer you may have a customer who wants to add a solar power system or a wind turbine.  Are there any regulations or standards that apply specifically to these systems?

Obviously, since it is an electrical system and is, when being used, the source of power, the rules in 33 CFR 183.401-460 ( apply as well as the ABYC standards in E-11 (, or in the rest of the world, ISO Standards 10133 and 13297 for electrical systems:



However, there are other considerations beyond how to install the system:

Solar Panels:

What types of panels to use?

There are basically two types of panel construction, rigid and flexible. Each has advantages and disadvantages. In addition you need to specify that the panel be suitable for marine use.  Most solar panels are not suitable for the marine environment. Panels are either mono or polycrystalline. Crystalline panels are very subject to shading and lose power output if even slightly shaded.  The better ones are glass covered to protect the panel from UV degradation.

Rigid panels are more efficient than flexible panels but flexible panels can be better for mounting on or as part of a curved surface. Some can even be sewn into fabric, such as awnings.  But flexible panels need to be much larger than rigid panels because they are about 50% as efficient as rigid panels.  Before you pick any panel make sure you check the specifications and the warranty.  Compare how efficient they are and how long they are warranted for.  Make sure they are warranted for marine use.


What type of controller to use?

There are basically three types of controllers, MPPT, PWM and shunting.  The least expensive but not the best of these is the shunting.  The MPPT and PWM are better at controlling the voltage and current and making sure the batteries are topped off at 100% charge. Make sure you compare the differences between controllers. As you can see from this Wind&Sun page there are many to choose from.

In addition to a controller the positive wire from the panels or turbine must be fused (or a circuit breaker) to prevent overheating of the wires. Be sure to size the overcurrent protection based on current and length of the wire run. See Wire Size Sizes


Where and how to mount the panels so they are most efficient?

Panels need to be mounted where they will be exposed to direct sunlight for the maximum amount of time, which varies depending on what geographic region the boat is in. Obviously you will get more sun in tropical climes than in northern climes. Also if  mounting them on a sailboat you want to make sure they are not going to be shaded by the sails or masts. On power boats they are usually mounted on cabin tops, but on sailboats they are typically mounted on a stern railing or davit or some other appendage that sticks out away from the boat.

Sizing Panels:

Types, and specifications.  How to determine size and output?

The size of the panels and number of panels is determined by your electrical needs.  Primarily you need to size them to the battery bank so that the bank can be recharged in a reasonable amount of time without running a generator.  Of course your battery bank needs to be sized based on the electrical needs for your boat. See Electrical System Planning  See also Captain Curran's Sailing Blog

Wind turbines:

Wind turbines involve asking the same questions:

Wind Vs Solar. If you live or cruise in an area that does not get a lot of year round sun then maybe a wind turbine is a better choice.  Areas such as the Pacific Northwest are famous for not much sun but they do have very steady wind. So a wind turbine may supply your electrical needs better than a solar panel system.

One of the big issues with wind turbines is noise. They do make noise and on a sailboat this can be very annoying.  So this becomes a factor in selecting a wind turbine.

Location is another issue.  On a power boat placing the wind turbine on an upper deck or a cabin top is a good choice, but on a sailboat the turbine has to be mounted  where it will not contact the sails or rigging, and not contact a dock or other shore side item that may stick out towards the boat.  So careful consideration must be made of the location.  It is advisable to temporarily mount the wind turbine and check if it is going to interfere with anything on the boat.

Controllers: See the above for solar panels.  The same requirements apply. You need a good controller to recharge the batteries to the max and not damage them.


The above is very simplified and hardly begins to address the issues involved in selecting and installing a solar power or wind turbine system.  Do your research. Ask Questions.  Hire a consultant. As with all things boatbuilding, do it right the first time and do not do it on the cheap. It simply will not last or perform to your expectations and your customers will be dissatisfied with the installation and with you.

For boat owners:

Many people who own boats do their own electrical work. If the boat has a simple system, a battery, running lights, and a few instruments, then this is probably not a problem.  But as you add instruments and electrical devices to your boat the system can get very complex. It gets even more complex if you add AC appliances and bring in power from the shore or from other sources such as a generator, solar power system, or wind turbine.  You may have to add more batteries to run all the appliances,  an inverter to supply AC power, and overcurrent protection (circuit breakers or fuses) and switch panels.  If you do this it is time to get assistance from a professional.  But if you do, make sure the professional is a certified marine electrician or marine electrical engineer.  Electrical systems on boats are different than on shore!  In particular,  the way systems are grounded and how DC systems and AC systems are connected is significant.  Doing it wrong can mean your life, or at least the safety of your boat and boats around you.  The American Boat And Yacht Council, ( has standards for marine electrical systems, and provides courses and certification for marine electricians.  Ask the electrician if they are ABYC certified.  If they don't know what you are talking about, find someone who does.

In addition the US. Coast Guard and boating authorities in many countries, have specific rules you must follow for a safe installation. See Ike's List - Electrical for sources

Also look at Electrical systems for more information. .

Keep in mind.  There are two systems on a boat where you should never try to scrimp or save a few bucks, Electrical Systems and Fuel Systems. 

If you do your own electrical work make sure you follow some simple safety rules

There is a very good web page on installing a solar power system written by Kevin Curran on his Blog,  Captain Curran's Sailing Blog  He explains in detail, and in a simple and thorough manner how to install a solar power system on your boat.

Wind Vs Sun:


References for solar power systems: (some of this also applies to wind turbine systems)

Sierra Solar: Electrical Systems On Boats
Compass Marine: Installing a small marine solar system
Electric and Solar Powered Boats
Solar Power Installation On The Sailboat Groovy
West Marine Advisor: DIY Solar Power Installations
Whole Sale Solar: Solar Power Systems and Controllers
Wind&Sun: Charge Controller Basics
FreeSunPower: Charge Controller Basics
Custom Marine Products: Solar Panels
Energy Informative: Mono VS Polycrystaline Panels

References for wind turbines:

eMarine: Wind Turbines

Standards for Solar Power Systems

Solar ABCs (Applies only to the products not to the installation of the system on boats)

General Information about Solar Power:
Solar Action Alliance 2016 All rights reserved. Revised 04/28/2021