Powering Your Marine Electronics with Solar Panels


Solar power has finally come of age, bringing units small and portable enough for use in boats, autos and campsites. Earlier problems with size and efficiency have now been solved, and shoppers can choose from an array of versatile solar units with enough capacity to fully replace conventional generators.

The Old Way

Photovoltaic panels were once huge, heavy and inefficient. Powering the electrical systems of a boat with them was impractical, and the only other options for the boater were noisy generators run by diesel, gas or oil. These required frequent refilling, and the smell and noise interfered with the appreciation of nature.

The inconvenience reached beyond the individual user. Unlike automobiles and other larger fuel-burning devices, portable generators were not closely regulated or designed for emissions efficiency. Soot and harmful gases poured out of them at very high levels in proportion to the amount of usable energy obtained.

The New Way

Solar power presents none of these problems. It is silent, pollution-free and makes no odor. There are no fuel tanks to fill or replace. Solar panels are relatively inexpensive to make, recouping their manufacturing cost in 1.5 years in southern latitudes, 2.5 years in northern latitudes.

Since no fuel is being burned, no heat is created. Fuel-burning generators may heat up your cabin and make a hot day even hotter, but solar panels will not.

The efficiency with which solar panels convert sunlight into usable electricity has grown with the advancing technology and now ranges from 6 percent with amorphous silicon-based panels to 44 percent with multiple-junction arrays. These are extreme limits, but even commercially available units can achieve between 14 and 22 percent efficiency, allowing trickle-charging of batteries or running of appliances such as a TV or refrigerator. The same panel system can supply DC current for the boat’s electrical devices or, when used with an inverter, AC current for other appliances. 

Easy Installation, Long Life, Versatile Designs

Today’s photovoltaic panels are smaller, lighter and more flexible than their predecessors were. Many can be installed without the drilling needed for older models. 

Shoppers can choose from rigid, flexible and semi-flexible models. Rigid ones are sometimes called crystalline panels and are composed of arrays of cells attached at the edges to form inflexible panels. These have a higher efficiency than the flexible models and last up to ten times longer, often carrying warranties of 20 years compared to only two to five years for flexible panels. 

However, flexible solar panels, sometimes called thin film panels, are relatively inexpensive and easy to replace, making them attractive in some applications. Flexible solar panels can be laid out and moved around at will, then rolled up and stowed when they are no longer needed. They are made from tough, weather-resistant materials and stand up well to salt and other corrosives. This is also true for the accessories used with them such as voltage regulators and inverters. Besides their relatively short life, the biggest disadvantage of flexible panels is that they blow freely in the wind, making it necessary to weight the corners or tie the edges down in windy weather.

Rigid panels can be mounted on metal poles and easily attached to a deck or railing when needed, then folded and stowed away when the batteries are fully charged. Alternatively, they can be incorporated into the boat’s construction as roof panels. Some rigid panels will fold accordion-style to facilitate storage.


With the variety and improved efficiency available today, solar power can be used for several common jobs on a boat or dock:

• Boats in moorings or storage- Often when boats are stored in a marina, on a trailer or on moorings, power from shore is not available. Solar power is ideal for these locations.

• Battery charging- Unattended arrays of batteries can be left attached to solar panels so that maximum charge is maintained for quick readiness.

• Pumping excess water- Rain can flood a boat and make the bilge pump run constantly, depleting the batteries. A solar power system can run the bilge pump while it is charging the batteries.

• Power at the destination- Sometimes the best getaways are too remote for grid power. In these places, the same system that powered the boat can also do so for a cabin or tent.

Most solar panels are modular, allowing the attachment of new cells as needed. Cloudy weather may reduce power output, but enough power will still be generated to allow at least minimal systems to keep operating.