Green Technology

How Many Photo voltaic Panels Do I Want For My Boat?

Are you battling the variety of photo voltaic panels it’s essential set up in your boat? We’ll allow you to discover the reply!

Putting in photo voltaic panels in your boat is the finest strategy to generate clear and free vitality to cost your boat’s batteries and maintain your home equipment operating.

Photo voltaic panels aren’t noisy like wind mills. They don’t launch dangerous gases like gas-powered mills and don’t injury your batteries over time, which might occur while you use your engine’s alternator to cost your home batteries.

As an alternative, they harness vitality from the solar to create DC electrical energy, which is saved in your batteries and used to energy your boat’s home equipment.

Nevertheless, all of those perks come at a comparatively excessive value.

So to keep away from spending more money on a photo voltaic setup too large in your wants (and in addition in your boat), place to begin is to estimate what number of photo voltaic panels you want in your boat.

On this article, we assist you determine what number of photo voltaic panels you want in your boat. We additionally focus on the forms of photo voltaic panels and which is finest for boats.

Lastly, we present you the common costs for marine photo voltaic panels.


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How Many Photo voltaic Panels Do I Want For A Boat?

In case you suppose that sizing a photo voltaic array in your boat follows the identical course of as it could in your residence, you’d be incorrect. 

It’s because land-based photo voltaic panels are fastened. Furthermore, you may angle them towards the solar to extend total efficiency. 

It’s straightforward to know why you may’t do that with photo voltaic panels on boats.

When cruising in your boat, the photo voltaic arrays repeatedly transfer relative to the solar, so reaching an optimum photo voltaic achieve orientation/angle is sort of inconceivable.

Because of this (and some others, like wind, partial shadow, and many others.), land-based photo voltaic calculations don’t apply properly to boats.

However don’t fear; we present you a straightforward strategy to estimate what number of photo voltaic panels you want in your boat.

Sizing A Photo voltaic Array For Your Boat

For the estimation, you first need to reply a couple of questions, corresponding to:

  • Do you wish to rely solely on solar energy, or will you continue to use your alternator or generator to cost your home batteries partially?
  • In case you’re solely utilizing photo voltaic vitality, what’s your estimated every day electrical energy utilization?
  • How a lot room do you will have in your boat (to put in the panels)?
  • What number of peak solar hours will you get every day (based mostly on location)?
  • For the way lengthy will you run every equipment/machine?

After getting the solutions to those questions, you can begin calculating the variety of photo voltaic panels it’s essential set up in your boat.

Solar panels mounted on a boat
The variety of photo voltaic panels it’s essential set up in your boat is determined by a number of elements. Nonetheless, most significantly, it is determined by your common vitality consumption and the way a lot house you will have for the panels.

How To Calculate The Quantity Of Photo voltaic Panels For A Boat

1. If You Need To Rely Solely On Photo voltaic Energy

In case you want to energy all of your boat units and home equipment solely with solar energy, then right here’s the way to calculate the variety of photo voltaic panels you’ll want to put in in your boat.

Before everything, it’s essential decide your common every day electrical energy utilization.

You may both categorical your every day utilization in watts per hour (Wh) or amp-hours (Ah). The latter is less complicated in terms of boats as a result of most boat units and home equipment run on DC electrical energy, so that you want your panel to provide the identical quantity of Ah that you simply eat every day.

Most home equipment have ampere scores written on them, normally on the again. Conversely, for those who solely discover the wattage, divide it by the rated voltage of the machine since:

Amperage (A) = Wattage (W) / Voltage (V)

Step 1: Make A Record Of Your Home equipment

Make an inventory with the amperage of every equipment and the variety of hours per day you propose to make use of every. Right here’s an instance:

EquipmentAmperage (A)Hours of use (every day)Ah per day (A x h)
Mini Fridge5 A8 h40 Ah
Recent Water Pump9 A1 h9 Ah
Small TV6 A2 h12 Ah
Stereo1.5 A2 h3 Ah
Telephone Charger0.5 A2 h1 Ah
VHF Radio0.6 A8 h4.8 Ah
Three LED lights0.7 A (every), 2.1 A complete4 h8.4 Ah
Chartplotter / GPS0.85 A8 h6.8 Ah
Broadband Radar1 A4 h4 Ah
(All home equipment talked about on this chart use DC electrical energy)

Then, calculate the full sum of Ah consumed per day. For our instance (desk above), the full is 89 Ah.

Add an additional 15% to your every day consumption to account for inefficiencies. So, 89 Ah x 1.15 = 102.35 Ah (let’s contemplate 102 Ah).

Step 2: Divide The Complete Ah By The Quantity Of Solar Hours

When you’ve calculated the quantity of Ah you eat every day, divide this quantity by the common every day peak solar hours (in keeping with your location).

As a result of you may’t strictly goal your panels towards the solar, let’s assume about 4 hours of whole rated present output per day, on common, for the Northern climates. (For locations nearer to Ecuador, you may contemplate 5 hours of peak solar hours/day.)

This manner:

Ah Required Each day / Common Peak Solar hours = 102 Ah / 4 h = 25.5 A

Due to this fact, your photo voltaic array ought to be large enough to supply 25.5 A per hour of solar.

Now, divide this quantity by the working present of your chosen photo voltaic panel.

As an illustration, for those who select to make use of 200 W monocrystalline photo voltaic panels (working present is normally 8.5 A for an 18 V module), you then’ll want to put in 3 photo voltaic panels:

Amps required per peak solar hour (A) / Panel’s Working Present (A) = 25.5 A / 8.5 A = 3 panels

Merely comply with these calculation steps to estimate what number of photo voltaic panels you want in your boat.

What for those who don’t have sufficient house in your boat so as to add that many panels? On this case, contemplate including modules with increased energy output. You would possibly be capable to produce the identical quantity of vitality whereas utilizing much less house.

Alternatively, examine the opportunity of utilizing a pole mount to put in your photo voltaic panels.

2. If You’ll Use Photo voltaic Simply to Partially Cost Your Home Batteries

Including photo voltaic panels remains to be a sensible selection even when you’ve got different vitality sources in your boat — like your alternator or a typical generator.

The apparent cause is that photo voltaic vitality is clear and renewable, will not be loud and dangerous like a generator, and doesn’t probably lower your battery’s lifespan (which might occur when charging batteries with an alternator).

On this case, you may measurement your photo voltaic array in keeping with the measurement of your battery financial institution.


Let’s say you will have a 200 Ah battery financial institution, and you utilize your alternator to cost 75% of your financial institution’s capability and your photo voltaic panels for the final 25% of capability (so from 75% to 100% state of cost).

On this case, you’d want your photo voltaic panel system to provide 57.5 Ah per day to cost your battery financial institution absolutely. To be protected, add an additional 15% to account for inefficiencies. This manner, you’ll want to provide roughly 66 Ah (57.5 Ah x 1.15 = 66.125 Ah).

Now, it’s essential learn how many panels it’s essential set up to provide this quantity of amps every day. This is determined by the wattage of the panel you wish to use.

For A 100W Versatile Panel

The open circuit voltage of an 18V, 100W versatile monocrystalline photo voltaic panel, is normally 22.5V. Due to this fact, its working present is:

Working Present (A) = Wattage (W) / Voltage (V) = 100W / 22.5 V = 4.44 A

Due to this fact, in a day (contemplating 4 peak solar hours), a single 100W versatile mono panel will produce:

Working present of a 100W panel x peak solar hours = 4.44 A x 4 h = 17.76 Ah (let’s contemplate 17 Ah)

So, to provide 66 Ah a day, you’d want:

Complete Amps you want / amps a 100W produces in a day = 66 Ah / 17 Ah = 3.88 (4 panels)

You’d want 4 100W versatile monocrystalline photo voltaic panels for this.

Please word: to soundly use an 18V photo voltaic panel to cost a 12V battery financial institution, you could add a cost controller to your photo voltaic setup. In any other case, your battery financial institution can overcharge, inflicting injury or shortening your battery’s lifespan.

For A 200W Inflexible Monocrystalline Photo voltaic Panel

We will merely repeat the earlier calculations, changing the wattage and voltage specs.

Contemplating the open circuit voltage as 22.5 V, let’s calculate the panel’s working present:

Working Present (A) = Wattage (W) / Voltage (V) = 200W / 22.5 V = 8.88 A

Due to this fact, in a day (contemplating 4 peak solar hours), a single 200W inflexible mono panel will produce:

Working present of a 200W panel x peak solar hours = 8.88 A x 4 h = 35.52 Ah (let’s contemplate 35 Ah)

So, to provide 66 Ah a day, you’d want:

Complete Amps you want / amps a 200W produces in a day = 66 Ah / 35 Ah = 1.88 (2 panels)

On this case, you’d want two 200W photo voltaic panels or 4 100W versatile monocrystalline photo voltaic panels for this.

As anticipated, for those who double the wattage of the panel you’re utilizing, you’ll want half of the variety of panels.

Are Boat Photo voltaic Panels Totally different From Residence Panels?

Sure, there are totally different photo voltaic panels; relying on the case, one could be preferable over the others.

Principally, boat photo voltaic panels ought to be capable to face up to the cruel marine surroundings, which might be robust on tools — particularly salt water.

Due to this fact, boat photo voltaic panels ought to be well-sealed and waterproof (IP65, IP67, or IP68), and the digital elements on the again of the panel ought to be encased in an inert non-corrosive waterproof materials (like silicone).

As well as, marine-grade photo voltaic panels are normally constructed with bypass diodes to cut back the influence of shading on a ship.

One other issue to contemplate is the uneven surfaces you discover on totally different boats. Marine photo voltaic panels are normally manufactured from extra versatile supplies to make the set up simpler on numerous surfaces (inflexible, curved deck, bimini high, and many others.).

Furthermore, the versatile/curved variety can typically assist optimize efficiency as soon as it will possibly offset the angle variations between the solar and the panel when the boat is transferring.

Are Versatile Photo voltaic Panels Extra Really helpful For Boats?

When it comes to rigidity, there are three important forms of panels:

  • Inflexible Photo voltaic Panels (residence photo voltaic panels)
  • Semi-Inflexible Photo voltaic Panels (additionally referred to as “walk-on” panels)
  • Semi-Versatile

Generally, the semi-flexible photo voltaic panel is the popular sort for marine functions. Nevertheless, this won’t be the case for you.

As an illustration, when you’ve got a big boat with sufficient house to put in extra strong photo voltaic panels, the semi-flexible panels is probably not your only option.

So be certain to do your analysis earlier than making your ultimate choice.

And that can assist you with that, we’ll focus on every sort of panel individually.

Inflexible Photo voltaic Panels

Usually, the usual residence photo voltaic panels comply with the identical design: a inflexible steel body that holds collectively a number of totally different layers of fabric, together with photo voltaic cells and tempered glass.

They’re normally 1.2 to 1.5 inches thick  (roughly 30 to 40 mm), and also you’ll most likely must drill holes within the boat’s floor to mount these panels correctly. This is without doubt one of the downsides of the inflexible sort panel.

Rigid solar panel, can also be used on boats
Parts of a typical residence photo voltaic panel (inflexible photo voltaic panel).
Supply: cleanenergyreviews.information

One of these panel is usually giant and heavy, so it’s not the best choice for small boats.

It’s splendid for mounting on a inflexible boat floor or top-of-pole mounting.

Rigid solar panels on a boat's rigid surface
Inflexible photo voltaic panels on a ship’s inflexible floor. It is strongly recommended for giant boats with sufficient house to put in the panels.
A rigid solar panel on a pole mount on a boat
A inflexible photo voltaic panel on a pole mount. You may rotate the panel to get extra daylight and maximize energy output.

The inflexible photo voltaic panels should be waterproof for marine functions and have anticorrosion frames, marine-grade sealants, and a water safety junction field.

Inflexible panels are strong and environment friendly; if adequately cared for, they will final a few years.

So when you’ve got the house in your boat (with flat surfaces or pole mounts) and your energy demand is comparatively excessive, you may contemplate putting in inflexible photo voltaic panels.

Nevertheless, there are a number of explanation why inflexible panels wouldn’t be best for you, corresponding to:

  • You could have restricted house
  • Your boat has curved surfaces
  • You want a light-weight panel to put in in your bimini high
  • You may’t add an excessive amount of weight to your boat
  • Your energy demand is low

If that’s your case, it’s best to contemplate the semi-rigid (“walk-on”) or versatile photo voltaic panels.

Semi-Inflexible Photo voltaic Panels

A semi-rigid photo voltaic panel might be barely bent to match a curved floor (with a bending angle of not more than 30 levels). It’s splendid for mounting on a curved deck floor.

It may achieve this as a result of it has no glass layer or aluminum body. Because of this, these panels are significantly lighter than inflexible panels however heavier and stiffer than semi-flexible panels.

Multiple solar panels needed on a boat
Discover these panels might be barely bent to regulate to the curved floor of the boat.

A semi-rigid panel has a robust aluminum backing and an additional thick ETFE laminate non-slippery floor (encapsulating the photo voltaic cells).

Semi-rigid solar panels are ideal or boats
Discover the additional thick ETFE laminate that protects the semi-rigid photo voltaic panel.
you can walk on semi-rigid solar panels for boats
Due to its protecting laminate, you may stroll on it with no danger of damaging it.

The semi-rigid photo voltaic panels are highly regarded for boats and van roof racks as a result of their set up doesn’t require drilling any holes.

As an alternative, they are often bonded to a easy floor utilizing adhesive silicone (like Sika-Flex 252) and even velcro.

To keep away from overheating (which decreases efficiency), the panels want a small air hole to dissipate the warmth. You may obtain this by placing a spacer behind the panel, offering simply sufficient house for air to move between the panel and the floor/roof (you should utilize double-sided tape, velcro, or plastic cardboard corresponding to Coroplast®).

Semi-rigid solar panels are the perfect option for a boat
Semi-rigid panels are a wonderful choice for marine functions on account of their light-weight and sturdiness. You can even stroll on them, making it simpler so that you can transfer in your boat.

As well as, the sort of panel is way lighter and thinner than its inflexible counterpart whereas nonetheless producing the identical quantity of energy.

Nevertheless, the light-weight benefit can grow to be a weak point in excessive winds.

Why? As a result of and not using a safe set up, these panels can take off like kites.

Because of this, be sure you’ve chosen a top quality set up choice.

Lastly, it’s important to level out that this expertise is comparatively new and costly, particularly since there aren’t that many firms providing the sort of product ( instance is Customized Marine Merchandise, which gives a number of photo voltaic panels within the U.S. for boats).

Versatile Photo voltaic Panels

Versatile photo voltaic panels are designed to contour to curved surfaces and are particularly properly suited to set up on boats with uneven surfaces.

They’re extraordinarily skinny (roughly 2mm) and light-weight, making them straightforward to move, set up, and retailer.

So if it’s essential set up a photo voltaic panel on a curved floor (with a bending angle of a bit over 30 levels) or if the floor can’t help quite a lot of weight, then a versatile photo voltaic panel is your only option.

flexible solar panels for boat
A versatile photo voltaic panel is an ideal answer for many who want a bendable and light-weight panel for his or her boat.

As a result of versatile panels are very light-weight, you may safely mount them on a bimini high or dodger with out worry of collapsing.

flexible solar panel on a bimini top
Versatile panels are tremendous straightforward to put in. You should use velcro or a silicon adhesive.

Moreover, versatile panels are waterproof and dissipate warmth higher than semi-rigid panels.

Nevertheless, they lack the additional thick ETFE laminate safety (they’ve an “ultra-thin lamination”), in order that they’re much less strong, and strolling on them will not be advisable as it would end in inner injury to the photo voltaic cells and soldering.

Furthermore, their lifespan is way shorter when in comparison with the lifespan of normal inflexible photo voltaic panels. Producers normally supply a 5-year guarantee for the fabric.

For these causes, it’s not shocking that versatile panels are less expensive than semi-rigid panels.

flexible solar panel needed for boats
When the boat is transferring, the orientation (of the panel relative to the solar) is continually altering. Nevertheless, the curvature of a versatile panel may help optimize its efficiency as a result of it will increase the adjustments for the optimum tilt angle.

Under you will discover a desk through which we evaluate the load and thickness of a 100W inflexible monocrystalline photo voltaic panel and a 100W monocrystalline versatile photo voltaic (each from Renogy):

SpecificationRenogy Versatile Photo voltaic PanelRenogy Inflexible Mono Photo voltaic Panel
Wattage100 W100 W
Weight4 lbs (1.8 kg)16.5 lbs (7.5 kg)
Thickness0.08 inches (2 mm)1.2 inches (30 mm)
Working Voltage18.9 V17.9 V
Working Present5.29 A5.72 A
Manufacturing Per Day (U.S. Common)400 Wh / day400 Wh / day
Effectivity21.0 %21.0 %
Common Value$ 190$ 120

And for those who’re curious to see how a lot the versatile photo voltaic panel from Renogy might be bent, right here’s a video for you:

How A lot Do Boat Photo voltaic Panels Price?

Boat photo voltaic panels can value anyplace between $150 to $1600 (U.S. {dollars}).

The next desk displaying examples of versatile and inflexible photo voltaic panels and their common costs:

ProducerMost Energy OutputKind of Photo voltaic PanelValue (U.S. {dollars})
SunPower100 WVersatile, Monocrystalline$ 200
Renogy100 WVersatile, Mono$ 160
High Photo voltaic100 WVersatile, Mono$ 140
Renogy175 WVersatile, Mono$320
Renogy100 WInflexible, Monocrystalline$129
BougeRV200 WInflexible, Monocrystalline$280
Renogy200 WInflexible, Monocrystalline$270
Newpowa240 WInflexible, Monocrystalline$280
Renogy320 WInflexible, Monocrystalline$360
LG375 WInflexible, Monocrystalline$365
BougeRV400 WInflexible, Monocrystalline$540
Trina Photo voltaic400 WInflexible, Monocrystalline$330
Panasonic400 WInflexible, Monocrystalline$505

As you may see, versatile panels are inclined to value greater than inflexible panels (evaluating panels with the identical wattage).

Which Components Dictate The Price Of A Photo voltaic Panel For Boats

The worth of photo voltaic panels for boats is determined by the panel’s most energy output, amongst different elements, corresponding to:

  • Producer
  • The rigidity of the photo voltaic panel (inflexible, semi-rigid, semi-flexible)
  • Kind of panel (monocrystalline, polycrystalline)
  • The expertise used (commonplace, PERC, half-cell, and many others.)

Let’s focus on these elements a bit additional.

Each day Energy Output (How A lot Energy The Panel Generates)

It’s no shock that, in terms of a PV module, the extra energy it will possibly generate (the larger its wattage), the extra it should value.

However you would possibly be capable to use this worth distinction to your benefit.

As an illustration, let’s say you’ve calculated that it’s essential generate 400W with photo voltaic panels. On this case, you will have a couple of choices:

  • Including one 400W photo voltaic panel
  • Including two 200W photo voltaic panels
  • Or including 4 100W photo voltaic panels

In fact, the best choice is determined by how a lot house you will have in your boat to put in your photo voltaic panels. However when you’ve got choices, attempt operating the mathematics earlier than buying.

You would possibly save a couple of dollars and nonetheless generate the identical quantity of energy in the long run.

Monocrystalline vs. Polycrystalline

Monocrystalline photo voltaic cells are manufactured from a single silicon crystal, in order that they’re smaller/lighter, extra environment friendly, and might endure increased temperatures.

Conversely, polycrystalline photo voltaic cells are manufactured from a number of silicon crystals melted collectively. Due to this fact, photo voltaic panels made with polycrystalline photo voltaic cells are usually bigger and fewer environment friendly.

Due to its many benefits, monocrystalline panels are usually dearer than polycrystalline panels.

monocrystalline solar panel versus polycrystalline solar panel
Supply: American Photo voltaic Power Society

As a result of boats normally don’t have that a lot room to spare, it’s wiser to put in essentially the most environment friendly sort of photo voltaic panel, the monocrystalline.

It would require extra upfront funding, but it surely takes up much less house and generates extra vitality (when in comparison with its polycrystalline analog).

Inflexible vs. Versatile Photo voltaic Panels For Boats

As beforehand talked about, there are a couple of totally different photo voltaic panel choices: inflexible, semi-rigid, and versatile.

As a result of their expertise has been round for longer, inflexible photo voltaic panels normally value much less than their semi-rigid and versatile analogs.

Of the three varieties, the semi-rigid is the most costly. Nonetheless, it’s additionally essentially the most advisable for boats because it combines the sturdiness and effectivity of a inflexible panel with the versatile panel’s capacity to bend.

As well as, the marketplace for semi-rigid panels remains to be very small, and only a few firms supply the sort of product (examples are: Solara in Europe and Customized Marine Merchandise within the U.S.).

Let’s evaluate the price of versatile and inflexible panels with the price of semi-rigid panels:

Price Of Semi-Versatile Monocrystalline Photo voltaic Panels For Boats

Photo voltaic Cell ProducerEnergy RankingAmp-hours per day (6h of solar)Value per panel
SunPower55 W3.3 Ah$ 260
SunPower70 W3.8 Ah$ 319
SunPower115 W4.0 Ah$ 529
SunPower120 W6.1 Ah$ 499
SunPower130 W5.2 Ah$ 599
SunPower145 W6.6 Ah$ 725

Price Of Semi-rigid Monocrystalline Photo voltaic Panels For Boats

Photo voltaic Cell ProducerEnergy RankingAmp-hours per day (6h of solar)Value per panel
SunPower110 W50.8 Ah$ 659
SunPower120 W55.4 Ah$ 719
SunPower150 W69.2 Ah$ 899
SunPower175 W80.8 Ah$ 1,049

Inflexible Monocrystalline Photo voltaic Panels For Boats

Photo voltaic Cell ProducerEnergy RankingAmp-hours per day (6h of solar)Value per panel
SunPower110 W50.8 Ah$ 489
SunPower140 W65.6 Ah$ 629
SunPower150 W69.2 Ah$ 699
SunPower175 W80.8 Ah$ 799
SunPower200 W92.3 Ah$ 899
SunPower225 W103.8 Ah$ 999

Please word: we gathered all of the above worth data from the Customized Marine Merchandise’ web site.

If we evaluate solely panels of the identical wattage, we’ll discover that the worth will increase within the following order: inflexible panels < versatile panels < semi-rigid panels.

Remaining Ideas

Since boats don’t normally have a lot room to spare, it’s important to find out what number of photo voltaic panels you’ll want.

To do this, you could estimate your common every day vitality consumption and decide the variety of panels wanted to fulfill this demand.

In case you don’t have sufficient house in your boat, think about using extra environment friendly panels that may produce quite a lot of vitality whereas taking much less house.

The most effective sort of panel for boats is the semi-rigid (“walk-on” panels). These panels are comparatively new to the photo voltaic market and might be fairly costly.

Nevertheless, for those who don’t have quite a lot of free house in your boat and your every day vitality consumption is comparatively excessive, these panels might be your only option.

We hope this information has given you the required information to find out what number of panels you want in your boat and what sort of panel is extra advisable for boats.

In case you nonetheless have questions on this subject, be at liberty to achieve out to us; we’ll be joyful to assist!

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