Everything You Need To Know About Marine Solar Panels

Categories: Review and Solar PV Panels.

When You Can't Be Without Power Even At Sea

Marine solar panels might conjure an image in your mind of a beacon floating off the coast warning seamen of danger. Marine solar panels might be the best marine solar charger for your boat's batteries. But there is more to marine solar panels than the solitary ocean warning device or keeping the boat's battery alive so the white, green and red lights stay operating on your boat all night. 


Perfect warm weather and the calling of the sea beckon many to pack their bags and head out to sea. An ocean voyage needs electrical power for the beacons, lights, radio and other electronic devices that serve the boat to keep you safe. Plus, those gadgets are part of what we people of the land take as necessary utility items that form part of the normal comforts for daily living.

marine solar panels

Things like computers, mobile phones, game systems, cameras, GPS and electronic tools like them make life easier, especially when spending hours of your quiet time at sea.


Then there is the power requirement for a host of electrical appliances on board beyond the lighting and HF/VHF; there is refrigeration for keeping your food frozen and drinks chilled, visual entertainment systems to help during your chill time through to powering your sound system for listening to music. And power is essential out there for you being safe so the generator must stay in working condition.


Of course the sea is salty water in abundance and a voyage in the sea is fraught with a plethora of water related problems. If you use power generated from a fuel and air engine, the responsibility of maintaining the generator, fuel supplies and the environment lies with the user. Also sea water affects batteries even beyond the problem of keeping the batteries charged while enjoying your ocean cruising.


If you are dependent on a fuel generator for power, then your batteries can be charged when the generator’s engine is running. You need to be burning fuel to get batteries to stay charged, not to mention that storing fuel on board adds the risk of fire.  As well, holding fuel on containers means spending your cash on the fuel.

marine solar panels

The perfect cruise can be spoiled with a little problem. With the diesel engine failing it might leave the boat totally powerless. Maybe if the sailor had the best marine solar panels on board as an alternative source of power for charging marine batteries, then the risk of losing power, of not being able to communicate and living on the sea in darkness won’t arise. Marine solar panels come in handy for generating steady clean solar electricity.


There are several different types and sizes of marine solar panels available in the market.  You need to consider some basic questions about the type of solar panel you require for your boat.


Consider also the intended marine solar power application, the panel placement location and installation method, and the necessity of a regulator for the battery.

Types Of Marine Solar Panel

There are four types of marine solar panels that are commonly used by sailors. You can pick the type of solar panel that best fits your needs. Each one of these panels has its pros and cons, which need to be evaluated for your requirement.


The output of a solar panel depends on the sunlight being received by the boat solar charger. If the solar cell is shaded, even slightly, then its efficiency goes down. Some solar panels come equipped with a built-in bypass diode between every string or cell. This diode offers protection for the cell overheating that is caused from shading.


The four types of panels differ on the basis of their cell technology used.

  • Monocrystalline – These are the oldest type of solar cells and have developed the most over the past years. They are cut from single silicon crystals so the sliced cells are larger and contain less impurity. The large crystals are then cut cross-section wise into the small wafer-size of the individual cells. A group of such individual cells joined together in series, form a single solar panel. This cell type is rated high in terms of solar conversion efficiency so the panel can be smaller, and uses less space on your boat's top surface.
  • Multicrystalline or Polycrystalline- These cells are also made from single wafer slices of silicon crystals constructed from an ingot block containing multiple smaller crystals. These blocks are cut to create a large number of single cells. Because of its multi-crystalline structure this cell type has a slightly lower conversion efficiency than that of a monocrystalline cell. The prime differentiating factor between the two types of cell is the price point. The latter has a newer and slightly cheaper technology than used for making monocrystalline solar cells.
  • Thin Film - This solar technology produces panels that are less efficient than the two above and therefore needs a larger panels space. Thin film solar are more effective than the other two types of solar panels in low lighting, partial shading situations and for extremely hot weather, which adversly affects most panels output performance. Thin film solar panels are ‘shadow protected’, meaning they continue to generate electricity even when part of the cells are in a shadow.
  • This has to be a great advantage in case of sailboats which move and rock to constantly cast light and shadow on parts of the boat surface. These panels usually do not have a frame around them. Thin film panels are made by a process wherein photovoltaic substance is deposited onto a solid surface like glass or plastic. Despite ranking low on the efficiency meter, they are still a popular choice owing to their lesser price and flexibility.
  • Amorphous Silicon- Similar to thin film cells, they are the least expensive of the solar panels. They are made by depositing an active crystal silicon material onto a substrates like glass, stainless steel or plastic sheet. In the same way as thin film solar panels have a lower conversion efficiency, and are shadow protected, amorphous silicon solar panels a very much like thin film cells but are even cheaper to produce.

Solar panels are also differentiated on the criterion of flexibility. Flexible panels offer the same technology as the rigid panels but can be shaped to a surface or made to be lightweight. They are just easy to install and are lightweight. Flexible solar panels can be easily mounted on canvas such as a bimini top. A bimini top is the open-front canvas top for the cockpit of a boat and is usually supported by a metal frame.

Installation Options For Marine Solar Panels

When selecting the installation method for the solar panel on a boat, you might use a checklist. Here are some key considerations to include on the list.

  • The instructions from the equipment manufacturer should be at the top of your list. Their experience will  answer most questions as they arise.
  • Think about the amount of power you need. Consider the size of the solar panel and the amount of usable surface area on your boat to fix them. The less power needed on the boat means the smaller the panels required.
  • The configuration of the boat will determine where the wires running from the solar panels to the batteries should go. The cables must be marine grade (not automotive) wire. With flexible solar panels use a firm and sturdy backer board to ensure that the panels do not bend too far.
  • Finally, every piece of the solar power system you use on the boat should have some level of waterproofing.

Canvas installations

Lightweight marine solar panels can be installed directly into canvas biminis and dodgers either using velcro or zippers. This is a good way of attaching that involves stitching the velcro strips to the panels or an attachment side zipper on the canvas and the panel.


This kind of temporary attachment method allows easy removal of the panel when not in use and makes them easy to store. The method involves a little preparation but it's easy simple, cheap, efficient and looks consistent.

marine solar panels

Deck Installations

Solar Panels can be installed into the deck of your boat and there are several methods for doing that. One easy option is to use a two sided peel and stick adhesive to adhere the back surface of the marine solar panel directly to the deck. Another method uses fasteners and attachpoints held by double-sided VHB tape. These two methods have an aesthetic and practical advantage of there being no holes drilled into the deck.


Marine solar panels are used on the sea and need to be able to withstand extreme weather conditions. Any installation method used must ensure that all the edges of the panels are secured and sealed well. The supports under the panel must be sturdy enough to maintain the solar panel’s position in case it has to hold the weight of the people moving on the deck.


The wiring for solar panels installed on the deck is done at the back side of the panel. It runs through the length of the deck behind the panels, thus maintaining the aesthetic look of the boat as well.

marine solar panels

Davits and Rail Installations

When using glass solar panels, this system of installation is the best. Even for semi-flexible panels, davits and rail installation method can be used for the holding down the best marine solar panels.

Here is a video about the installation of a marine solar panel.

Why Go Solar For Marine

Primary benefits

The first reason the mariner is going to use solar is because there are massive savings made on fuel. Solar energy is considerably cheaper to produce than electricity being generated by a fuel powered generator.


The second factor is noise level. This is an important issue for a quiet life, to the cut down on the noise levels while you are at sea. A typical generator emits noise while it is powering up your boat or yacht. The best solar panels for marine use are silent.


The marine solar panels quietly and efficiently do the same task of generating electric power and save you from intense noise pollution. 


Another benefit derived from using solar panels on your boat is that you can charge your boat’s battery while you are not on board the boat. That means a sailor might anchor the boat mid-sea, turn their attention to activities like reading, scuba diving or fishing.


Having marine solar panels connected on board means that you can safely leave some electrical load on even while you are away snorkelling!

Advanced Technology Available

Marine solar panels have developed power for multiple applications over the recent years. There is a wide selection of solar power options available today for the multitude of onboard electronics. There are fixed large solar panels and portable solar panels used on marine vessels with equal effectiveness


Solar technology is embedded in high energy thin film panels that can be shaped to suit your craft that charge most batteries to useful levels at a significantly quicker rate than before.

Tax benefits

The US Federal Government offers a tax credit on solar energy.  There is a 30% tax credit that applies to qualified expenditures on purchase and installation of solar panels on a house.  The term house here does not connote only to your primary residence, but also includes your boat if it has a head for bunks and a galley for meals and is docked in the US.  


The boat can then be classified as a second home and falls under the purview of a tax credit. This 30% tax credit is available until December 31, 2019, and will continue at lesser rates until December 31st, 2022.  Also, the credit is retrospective for any equipment placed under service after 2006.

What Is Ahead For Marine Solar Power?

The latest development in marine solar power has been the marriage between wind turbines and solar power to harness the most renewable energy while at sea. That is more than a yacht and solar panel combination. Many marine vessels stand to gain from this wind and solar alliance including cruise boats, tourist catamarans, fishing vessels, offshore support vessels, survey ships, oil tankers, cargo ships, RoRo ships, patrol vessels and passenger ferries.


There is a new technology, EnergySail, that allows ships to harness the solar power with help from a computer controlled rigid sail or rigid sail array. The Aquarius MAS technology incorporates alarm handling, performance monitoring, and data logging platform along with the marine solar power system.
marine solar panels

Seaorbiter marine research vessel

The marine world has seen some great solar powered vessels sail the waters. The group range includes PlanetSolar’s Turanor, Seaorbiter, which is a marine research vessel, Solar Voyager, Duffy London’s super solar yacht, to the Helios Yacht. The list is growing rapidly with mariners recognising the threat of fossil fuels endangering the sea’s environment.


If you have an interest in boating, you may have already considered the opportunities that solar and wind energy options present.  Quiet solar power that works for charging your boat's batteries.


Check out one option for solar panels for your boat.

You might consider looking at the selection of portable solar panel blogs on this website. 

If you are interested in solar panel equipment, I have developed some review articles of some commonly available solar equipment. 

Do let me know how your solar equipment is performing with a comment below. 

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