Click below for details on specific marine solar panel types

The key to a high performance, high quality marine solar panel that will last is the quality of the solar cells used in the panel.  We use only the highest efficiency grade A+ solar cells.  Our panels are built with premium SunPower monocrystalline back contact solar cells, Bosch monocrystalline cells or polycrystalline high efficiency solar cells. Our solar panels have essential blocking and bypass diodes built in (to prevent power from flowing into shaded panels or from batteries into solar panels at night and improve performance when partially shaded), and potted (filled with silicone) junction boxes to protect the electronics from environmental damage.  Our rigid solar panels have strong anodized aluminum frames and marine grade sealants.  Our semi-flexible and semi-rigid solar panels average the same output per square inch as our rigid panels and are constructed with high quality ETFE laminates that won't deteriorate (turn milky) or delaminate from intense heat and UV exposure. We offer a 1 year warranty on all of our semi-flexible panels, a 3 year warranty on our semi-rigid panels and a 5 year warranty on our rigid panels.

Facts About Marine Solar Panels

rigid, flexible, monocrystalline and polycrystalline marine solar panels
​Panel Type - There are many articles written on the two types of solar panels, monocrystalline and polycrystalline.  Monocrystalline panels are made up of single crystal silicon wafers.  Polycrystalline panels are made using silicon wafers that have a multiple crystalline structure.  There are pros and cons to each type of panel.  Monocrystalline panels have a higher output per square inch in direct sun.  They can be sensitive to shading and output may degrade faster on cloudy days.  Polycrystalline  panels tend to have a lower output per square inch in direct sun but are not as sensitive to being shaded.  It is important to note that today's newer high quality polycrystalline panels perform within 5% of monocrystalline panels in full sun.  The premium monocrystalline SunPower cells used in our marine solar panels provide the best all around performance of any solar cells currently on the market.

Panel Solar Cell Quality - Because boats have a relatively confined space,  maximum power output per surface area is very important.  The quality of the solar cells used in solar panels is a key factor in determining the panel output.  Solar cells are passed under a standard light source and graded as to their output (1-10).  Grades are grouped into classes.  Class A (and A+) solar cells are grades 8-10, Class B solar cells are grades 4-7 and so on.  Solar cell quality follows a bell curve; there are many more Class B solar cells than Class A.  We at CMP specify only the best Class A-9 (A+) solar cells for use in our panels which results in a panel efficiency of 16-24%.   Less expensive Class B and C panels are often used on land based solar farms where space is not an issue.  Though a bit more expensive, our customers have reported that our solar panels often outperform the performance rating on the panel label.  
various sun angles for power differences to a solar panel during the day depending on sun angleAverage 5 Sun Hours in a Day
The Importance of Solar Cell Quality - Not All 100 Watt Solar Panels Are Created Equal - ​
​High quality high performance solar cells will produce more power at various sun angles than lower quality solar cells; up to 30% more power.  An important consideration in determining how much solar power you need is how many watt hours or amp hours of power you can expect to generate in a 24 hour period.  Let's say you cruise in an area that receives an average of 5 hours of full sun a day.  The average is computed based on the seasonal sun angle and the sun angle from morning through evening.  A 100 watt solar panel with average efficiency solar cells may produce 100 watts x 5 hours or 500 watt hours of power in a day.  At 13 volts that's about 38 amp hours in a day.  A 100 watt panel with high efficiency solar cells will produce up to 30% more power in a 24 hour period or 100 watts x 6.5 effective hours or 650 watt hours of power in a day.  At 13 volts, that's about 50 amp hours in a day.  38 amp hours vs. 50 amp hours in a day is significant on a boat.  Add more panels in the mix, say 400 watts and we see 152 amp hours vs.200 amp hours, a difference of 48 amp hours. This simple analysis does not take into consideration the impact of clouds or shading both of which will make the disparity even greater.   Clearly, the higher the quality of the solar cells the more power produced over time.

Panel Shape - The largest market for solar panels is commercial applications where many many panels are mounted on a roof or in a field.  These panels are usually rectangular in shape often twice as long as wide.   This shape is often not ideal for marine application.  Often a more square shape is preferable, especially for pole mounting.

Marine Grade - It's no secret that the marine environment, especially salt water, can be tough on equipment.  To withstand the rigors of the marine environment, solar panels should have strong stout anodized aluminum framing, should be well sealed and waterproof, and have the electrical box on the back of the panel encased in an inert non-corrosive waterproof material (like silicone) to protect the electronic components.
Quality marine grade solar panels are designed with bypass diodes to significantly reduce the impact of shading that so often occurs on a boat.

Choosing the right panel for your needs will require study and/or discussion with PV panel experts.  Our staff at Custom Marine Products are ready to help you design the best solar system for your marine needs.  Contact us via email or phone for a free consultation.

Flexible Marine Solar Panels with SunPower Solar Cells
Our SunPower monocrystalline cell flexible 55 - 145 watt high efficiency solar panels are manufactured to our specifications by highly acclaimed solar panel manufacturers. 
Unique features of our semi-flexible marine grade panels include the following:
  • Quality materials - We use impermeable ETFE laminates that will not cloud of degrade with exposure to intense UV light. 
  • Grade A+ SunPower solar cells -  The panels are comparable in performance to our rigid panels.
  • Mounting flexibility - Flexible panels will contour and flex against curved surfaces with a maximum bending radius of 30 degrees, ideal for mounting on a bimini top or a curved deck surface. 
  • Mounting options - Each panel can be affixed by high bond tape, snap, magnetic or screw mounting. Our screw mounting system has become the most popular method of attaching solar panels to canvas biminis and dodgers. Grommets are an added bonus for  ease-of-installation.
  • Plug and play - All panels come with industry standard waterproof MC4 connectors on 3 foot (1 meter) long pigtails.
  • Maximum output with shading - The panels are equipped with blocking and by-pass diodes so a shaded panel has minimal effect on the solar array performance.
  • Purchase options - These panels can be purchased individually or as a complete easy to install kit.  
  • Durable -  Although not recommended, the panels can be lightly stepped on. (For walk on panels see our semi-rigids)

Semi-​​Rigid Walk On Marine Solar Panels with SunPower Cells
CMP has just released a new series of semi-rigid walk on marine solar panels.  With a strong aluminum backing and very thick ETFE laminate non skid surface, these panels can be walked on and can conform to a slightly curved surface (5 degrees).  These panels are ideal for mounting on a slightly curved rigid boat or RV surface or on our top-of-pole mounting system.  We use premium SunPower Gen III solar cells with an efficiency rating of up to 23.7%, the highest efficiency available anywhere.  There is no glass and no aluminum frame so these panels are considerably lighter than our rigid panels but heavier and stiffer than our semi-flexible panel series.  The expected life of these panels is 15 years in the harsh marine environment.  The panels are available with a white or black backing.  They are available in 110,120, 150 and 175 watt power output. 

​Rigid Marine Solar Panels with SunPower Cells
The ideal marine solar panel must be highly efficient (maximum output per surface area) and robust enough to withstand the harsh marine environment.  We offer various sizes and types of solar panels to meet the unique needs of our customers.  For the cruising boat with modest power requirements, we recommend our 110 - 140 watt panels and for the cruising boat with greater power requirements we recommend our 140 - 200 watt panels.  These panels are excellent for mounting on a pole, a rigid deck top or a bimini frame.
Our rigid glass monocrystalline solar panels using premium SunPower solar cells are some of the most efficient marine panels available at over 23% efficiency.  These marine grade solar panels will perform extremely well in both full and partial sun, and when partially shaded.  They are built to withstand the harsh marine environment. 
Our 100 watt polycrystalline solar panel is an excellent overall performer in sun and cloud due to the use of very high quality Class A solar cells. It is tolerant of some shading from rigging. As with all of our rigid solar panels, the electrical box is sealed (potted) with inert silicone to eliminate any possibility of corrosion.
Marine Solar System controller Frequently Asked Questions (FAQ)

Why buy marine solar panels instead of regular solar panels?

Marine solar panels have five essential components that regular solar panels don't:

1. Sunpower Maxxeon cells - even if a cell is partially shaded they still produce power. Sunpower's A+ grade cells (Maxxeon) are among the best available putting out up to 23.7% efficiency, regular panels have far lower efficiency. This shows up over the course of a day in total watt hours produced, cheap panels will produce far less power at low sun angles (evening and morning).

2. Potted (silicone filled) junction boxes - this prevents corrosion of the electronics.

3. Available for deck mounting, bimini mounting, davit or arch mounting. Semi-rigid, Flexible, Rigid marine solar panels.

4. A+ grade solar cell quality. Cheaper solar panels will have lower quality, less efficient cells. Space is always at a premium in marine applications so the highest efficiency cells available are imperative. Highly efficient cells produce considerably more power at lower sun angles than lower grade cells.

5. Bypass diodes throughout the solar panels to significantly reduce the impact of shading that often occurs on boats.

What is the difference between a cheap marine solar panel and an expensive marine solar panel?

High quality high performance solar cells will produce considerably more power at lower sun angles than medium and low quality solar cells. An important consideration in determining how much solar power you need is how many watt hours or amp hours of power you can expect to generate over a 24 hour period. The higher the quality of the solar cells the more power produced over the full course of a day. Marine solar applications are generally more limited in space so higher solar output is usually important.

Call us any time for help with your marine solar panel purchase (248 705 8337), we're happy to talk you through sizing your panels and the design of your custom solar system. We specialize in marine solar panels, all types of boating solar panels.

Marine Solar Panel Specifications​ Summary

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Efficiently and Sustainably Powering Your Boat. Call us any time, we're happy to help you work through designing your boat's solar system.
Call 248 705-8337, 773 965-2546 or email [email protected]
Link To Our Article On How To Size Your Solar Panels For Your Boat