How To Select And Use 100 Watt Solar Panel For Boat?

100-watt solar panels are an excellent choice for boats. But they will work better on small cruising and fishing boats, sailboats, etc. You will have to calculate your boat’s total energy consumption before selecting the amount of 100-watt solar panels.

Are you looking for ways to select 100-watt solar panels for your boat? You are in the right spot then. Here in this article, I will show how you can choose 100-watt solar panels for your boat, how to determine how many panels you will need, and so on.

When you finish reading my entire article, you will know which type of 100-watt solar panel on your boat will provide the most output. So, let’s take this show on the road.

What are the performance of a 100 Watt solar panel?

A 100-watt solar panel can perform better with enough sunlight and no interruptions. But generally, it can produce 280 to 450 watts-hour with 4 to 6 hours of direct sunlight. It can produce up to 1 KW-hour per day with 8 hours of sunlight, cold weather, and every other factor at its best.

Things you can do with 100W solar panel depend on its Performance. How you mount your solar panel, the amount of overcast, the amount of sunlight, temperature, etc., are responsible for your solar panel’s outcome.

Here’s the output of a 100-watt solar panel under various circumstances:

CircumstancesPower Output
Full Sun-Straight Sunlight100%
Full Sun- 45° Angle Sunlight71%
Light Overcast60-80%
Heavy Overcast20-30%
Full Sun- Inside Single Pane Window91%
Full Sun- Inside Double Pane Window84%

Determine Why Do You Need a Solar Panel On Your Boat?

Like in your home and RV, a solar panel can be an optional or primary source of electricity in your boat. But to select a solar panel, you must know what you will use it for. Determining beforehand will give you a clear picture of the right 100-watt solar panel.

You can use 100-watt solar panels for several reasons. You can use them for:

  • Keeping the batteries fully charged while mooring.
  • Supplementing the existing power generation capability.
  • Generating enough power while anchored.
  • Charging and running small devices and appliances. 

After you have determined your needs and expectations, you can calculate the total amount of required power you will generate from the solar. Based on that, you will figure out how many 100-watt solar panels you need.

Which Boat Can Use 100 Watt Solar Panel?

Since a 100-watt solar panel produces enough electricity to charge and run small devices and appliances, you must be critical of where you can use it. As you are going to use it on your boat, you have to know which boats are better for this solar panel.

You can install 100-watt solar panels on small fishing boats, cruising boats, and sailboats. With this solar panel, you can fully charge your small boat’s battery while it’s on the trailer, mooring, or sitting idle.

This small panel can solve the problems you might face from a dead battery. On cruising and racing sailboats, you can use 100-watt solar panels as an additional or primary energy source. You might not have to use the boat engine to charge the battery when installing a couple of 100-watt solar panels.

How to Calculate Your Boat’s Power Consumptions

It is essential to calculate your boat’s power consumption before installing 100-watt solar panels. You will get a clear idea of how many panels you need. Doing it can be intimidating, but I’ll show you can complete this task easily.

  • First, list all the devices, appliances, lights, fans, and other electrical components you have on your boat.
  • Then calculate how much electricity all these components will consume in total. Make sure you take into account how many hours you are going to run each component.
  • After that, calculate how much power your boat will require on sailing and anchor days.
  • Finally, determine the size of the battery. Sum up the total consumption and multiply it by 3. There you have your battery size.

How Many 100-Watt Solar Panels Do I Need?

After calculating your boat’s total energy consumption, you can finally determine how many 100-watt solar panels you will need for an uninterrupted electricity supply. Generally, the electricity consumption depends on many factors like the boat’s size, number of components onboard, etc.

While navigating, a typical sailboat can consume up to 1000 watt-hour electricity per day with 12V batteries. We know that a 100-watt solar panel can produce 1000-watt-hour electricity in the best possible scenario.

So, to be safe, you should use at least 2 100-watt solar panels on your sailboat. Again, a 45-foot cruising boat typically consumes 150 amp-hours per day, and a 100-watt solar panel can produce 6 to 8 amp per hour. So, having 2 100-watt solar panels is the best choice.

Which Is Better For A Boat: Monocrystalline VS Polycrystalline?

There are two types of solar panels that you can choose from for your boat: Monocrystalline and Polycrystalline. You should be critical about which one you choose for your boat.

Monocrystalline solar panels are very sophisticated and are made from high-quality silicone. They are very sturdy and space-efficient. These panels have individual round cells that are precisely trimmed and utilize the highest from an area.

That’s why they look like tiles. Monocrystalline solar panels are energy efficient, heat tolerant, durable, and expensive, and the only downside is that they are less tolerant of shades.

On the other hand, polycrystalline solar panels have a simple manufacturing process. They are not very space-efficient and not trimmed either. But these solar panels are less expensive and tolerant to shades.

Considering all these factors, I suggest you go for monocrystalline solar panels if your budget permits.  

Which One To Choose: Rigid vs. Semi-Flexible Solar Panel?

There are two types of solar panels in terms of physical appearance: rigid and flexible solar panels. You have to choose which one would be the best for your boat. You can understand from the name that rigid solar panels are very sturdy, and you cannot twist them.

They are made of aluminum frames and very easy to mount. Made with solid metals, rigid panels are durable, energy-efficient, and shade tolerant. Besides, they are also less expensive and have a longer lifespan.

Semi-flexible solar panels are made of different materials and components. Because of their construction, they are flexible, and you can twist them to some extent. They are not as efficient as rigid ones, but their efficiency and durability have increased over the years.

I guess you could get your head around which one will suit your boat. You should use a rigid solar panel if there are no issues.

How to Mount a 100 Watt Solar Panel on a Boat 

Mounting solar panels on your boat isn’t that tricky. Your job is half done when you determine how many 100-watt solar panels you will need and what type of solar panels you will use. Now it’s time to install it.

  • Firstly, determine where you are going to mount the solar panels on your boat. There are some popular locations you can choose from. The top of a pole, Arch, Bimini, Deck, Side, etc., is some of the places you can mount your solar panel.
  • Then take your panels and mount them in the selected place. Make sure you attach them firmly so the wind cannot do any harm.
  • After that, you must connect your panels with the charge controller, battery, and inverter.
  • Finally, check the system after installation; your solar system is ready to use. You can also use a removable semi-flexible solar panel for additional usage.

Choosing The Right Kit For A 100 Watt Solar Panel

You will have to use the right kits to get the best out of your 100-watt solar panels. You need proper mounting gear for installing your solar panels. Another essential component is the battery. You have to choose a better battery.

A large battery will make your solar energy system suffer chronic undercharging, and a small battery will not store enough electricity. So, select one that matches the requirement. You must remember that 100-watt solar panels are compatible with 12V batteries.

An inverter is another essential component of a solar energy system, and it receives Direct Current and turns it into Alternating Current. Our regular devices use Alternating Current. Make sure you select one that’s compatible with your solar energy system.

Final Thoughts

I will conclude by saying one thing, 100-watt solar panel is a good choice for your boat. But you will need at least 2 panels for small power boats, cruising boats, and sailboats.

So, if you think you have enough space for at least two solar panels, do not hesitate to go with 100-watt solar panels. But if it’s not the case, I suggest you go for bigger ones.


P., T., Pournaris, M. . (2022, May 02). Solar Panels on Smaller Boats. Retrieved from BoatTest:

Sunaryo., Syahrihaddin, A., Imfianto, P. S. (2019). Solar Energy for a Traditional Coastal Fishing Platform. Journal of Marine Science and Application, 366-371.

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