Shining a Light on the 8 Best Marine Solar Panels

Shining a Light on the 8 Best Marine Solar Panels

The late great Lou Reed once sang that electricity came from other planets.

And he wasn’t far wrong, as electricity comes from the sun by the magic of solar power. Solar power frees you to travel the seas, safe in the knowledge that as long as the sun shines, there’s an endless supply of energy.

I speak from experience, having fitted 600 watts of solar panels to my canal barge. It means that for almost eight or nine months of the year, barring really overcast days, I can get all the power I need to liveaboard without the need to run my engine.

The ocean is one place where you can guarantee no obstructions from the sun, so it’s no wonder that solar power is a top energy choice for sailors.

Why Get Solar Panels?

In the world are two types of boaters: the liveaboard boater and the weekend or holiday leisure boater. Both will benefit from solar but in different ways.


The energy requirements for alive abroad boater are vastly different from a leisure boater. Managing daily energy consumption is a skill, and having solar means that you worry a little bit less about your batteries.

For a liveaboard, the solar panels will be more substantial, probably a minimum of 100 watts, and most liveaboard boats run with two or three panels, giving them a maximum of 300 watts.

That’s more than enough power to run a fridge, onboard equipment and laptops while in the middle of the ocean.


For leisure boaters, their energy requirements are far less crucial.

Sure, they want the same benefits, primarily, but there is not the demand for constant solar because the vessel gets used on an ad-hoc basis. It means that there is less need to fill the roof of the boat with masses of panels, unlike the liveaboard vessel.

Different Types of  Marine Solar Panels

Okay, so you’ve thought long and hard and have reached the momentous decision to get solar panels. But what are your options?

Flexible Solar Panels

Flexible panels are great because they adapt to whatever surface you wish to attach them. They flex, which means you can attach them to surfaces that are not perfectly smooth or flat. Given the unusual shapes and angles you find on ocean-going boats, this is an advantage.

Also, these types of panels are more robust, meaning they should easily stand up to the rigors of daily sailing life.

Advantages of Flexible Solar Panels

  • Fit to most surface shapes
  • Don’t need large amounts of space
  • Ideal for sea-travel
  • More robust

Disadvantages of Flexible Solar Panels

  • Fixed location means they cannot adapt to the conditions
  • Cannot be angled for better efficiency
  • Lower percentage conversion of sunlight to electricity

Fixed Solar Panels

Fixed solar panels are often attached to mounts that allow you to swivel and adjust the panel’s angle toward the sun. This process generates more energy than the flexible panels would because all they do is sit in a fixed position, relying on the sun’s rays hitting the panel. Solar will indeed operate in average daylight, but if you want the best performance, consider angling the panels.

Generally, fixed panels are more expensive to buy and need more significant maintenance and care. They aren’t as robust as their flexible counterparts and are also more awkward to mount.

Advantages of Fixed Solar Panels

  • Can be angled to increase efficiency
  • Higher percentage efficiency of sunlight to electricity
  • Need fewer panels
  • Can be mounted to most surfaces

Disadvantages of Fixed Solar Panels

  • Generally more expensive than flexible panels
  • Need more maintenance and care
  • Less robust

Monocrystalline Solar Panels

A silicone crystal “seed” is placed in a vat of molten silicone and slowly drawn upwards, as the silicone clings to the surface of the seed. Imagine a snowball gathering snow as it rolls, and you will understand. This process forms an ingot, which is removed from the vat and left to cool. It’s then sliced into wafer-thin pieces to develop the cells. It’s an incredibly wasteful process, as most of the silicone gets discarded.

The advantage of a monocrystalline panel is that they’re the most efficient variety, with some of the latest panels converting 22% of sunlight into electricity.

Because of their high productivity, they’re also space-efficient. Fewer panels are needed, making them ideal for the limited roof space on boats.

They also have a longer lifespan, which is why manufacturers place 25-year guarantees on them. They also perform better in warmer weather, so if you’re sailing around the sunnier climes, these panels would be ideal.

Advantages of Monocrystalline Solar Panels

  • Most efficient of all the solar panels
  • Higher productivity means fewer panels to mount
  • Typically have a 25-year guarantee
  • Perform better in warmer climates

Disadvantages of Monocrystalline Solar Panels

  • Wasteful manufacturing process
  • Generally more expensive to buy
  • Less robust than other solar panels

Polycrystalline Solar Panels

The manufacturing process for producing polycrystalline panels is very similar to the monocrystalline versions, in that a crystal silicone “seed” is immersed into a vat of molten silicone and starts to form an ingot. Unlike the previous method of drawing the silicone to the surface and removing it from the container to cool, creating polycrystalline cells, the molten silicone is allowed to cool with the silicone “seed” in situ.

Thought to be slightly less efficient than the monocrystalline versions, polycrystalline panels are cheaper to produce, making them the recent panel of choice.

They also create less waste, which is better for the environment, and have a lower heat tolerance than monocrystalline panels.

Advantages of Polycrystalline Solar Panels

  • Cheaper to produce
  • Less wasteful construction process than monocrystalline panels
  • More affordable
  • Better in colder climates

Disadvantages of Polycrystalline Solar Panels

  • Not as efficient as other solar panels
  • Less effective in warmer weather

Thin Film Solar Panels

Thin film panels are produced by placing a photovoltaic substance like amorphous silicon or cadmium telluride onto a solid surface like glass to form the cells. It produces less waste than traditional solar panel construction, and the cost saving is passed on to the consumer, meaning this is the cheapest option for those on a budget.

They also perform better in low-light and in cloudier days, whereas mono and poly panels will still work in those conditions, but need direct sunlight to reach their maximum performance.

The disadvantage of these panels is their efficiency when compared to monocrystalline panels, which have four times the performance. So that means you are going to need more panels and more space to produce the same energy. Plus, they degrade faster than the other two varieties, meaning that they come with shorter warranties.

Advantages of Thin Film Solar Panels

  • Cheapest of all the panel varieties
  • Perform better in low-light conditions
  • The least wasteful manufacturing process
  • Can be adapted to be flexible

Disadvantages of Thin Film Solar Panels

  • Four times less efficient than monocrystalline panels
  • Takes up greater roof space
  • Degrade faster so have shorter guarantees

What About Marine Solar Panel Wattage?

The most common solar panels are 100-watt varieties, but you can opt for more powerful ones.

At the other end of the wattage spectrum, you can find panels that generate 20 or 30 watts. These smaller panels are excellent for charging smaller electrical items like phones and laptops while you’re on the move, but you would need higher capacity if you’re a liveaboard boater, or you are embarking on an arduous journey across the ocean.

Solar panels typically come in wattage sizes of 30W, 50W, 100W, 150W, 200W and 300W. But as previously mentioned, for larger vessels, opting for two 300-watt panels might be the best option. Combined, they’ll still generate 600 watts and take up less room than three or four smaller panels.