According to Harvard University article, solar cost decreases will increase solar production by at least 700% by 2050. This means that solar boat panels may become one of the main components for any boat in the future.
Why is solar a great choice for your boat? Having a solar powered boat means you’re getting a lower power load and less penalty for carrying the extra weight. You can generate power as you go or at anchor, and store it, then use that electricity to power your motor, boat appliances and accessories when you need it.
Solar could very soon become one of our main sources of power.
Are solar panels for boats worth the investment? Definitely YES. Not only can they lower your power load, but you’ll also save money generating free electricity. Your solar boat may be able to take trips completely on solar. Having a solar sailboat means charging your batteries even while away, and having your boat ready to go when you get back.
Solar panels below are one of the best in quality, SunPower in particular. Whether you’re sailing across Lake Michigan or around the world they’re great for you to enjoy some free, clean, and quiet power.
What are the best solar panels for boats in 2021?
- SunPower Flexible 100W Monocrystalline.
- Newpowa 100W 12V Semi-Flex.
- SunPower 110W Flexible.
- RICH SOLAR 100Wx2 12V Polycrystalline.
- Topsolar Flexible 100Wx2 Bendable.
- SunPower Flexible 50W Monocrystalline.
- HQST 100W 12V Monocrystalline.
- Renogy 100W 12V Solar Starter Kit.
- Newpowa 100W 12V Polycrystalline.
- Newpowa 25W Monocrystalline 12V.
- Renogy 100W 12V Monocrystalline.
- WEIZE 100Wx2 12V Monocrystalline.
- Newpowa 30W Monocrystalline 12V.
Most efficient flexible solar panel
SunPower and Maxeon offer the best flexible solar panels in the industry. Highest quality, flexible, durable, and highly efficient. Curved solar panels usually bring lower efficiency, but with SunPower, you get the highest conversions in the industry.
- Highest efficiency in the industry 22-25%
- lightweight and top quality build
- Charges even on cloudy days
- a high-quality top polymer layer
Best ultra-flexible solar panel
Newpowa is known for good quality, and this 100W semi flexible solar panel is one of the best at the moment. It’s highly flexible and light, yet stiff and robust. You’ll know when you see it, the quality speaks for itself.
- high quality build, flexible but stiff
- great output at lower light levels and sub-optimal angles
- very easy to position and mount
- easy to manage, lightweight and durable
Highest quality marine solar panel
Flawless solar panel, SunPower delivers only the best solar panels for boats, and you won’t be disappointed.
- the highest efficiency in the industry
- Lightweight and portable
- durable, reliable, high-quality build
- may need to buy a tool to disconnect
Best solar panel for the money
These RICH SOLAR panels are one of the best solar panels for the money, right now. They can put out above 100W in the clear sun, and yet give you excellent low light performance as well. Great for trolling motors and boat appliances, solar homes, and RVs.
- high efficiency and sturdy design
- can produce above 100 watts
- good even in low light
- cheap and affordable
Best flexible solar panel for the money
This is an excellent semi-flexible solar panel, with good conversion efficiency. Bendable solar panels are great if you don’t have the space to mount the fixed ones, especially on a narrowboat.
- high conversion efficiency for a flexible panel
- lightweight, and easy to install
- high quality ETFE material, great looking
- more resistant than aluminum solar panels
Most efficient 50W Flexible Solar Panel
If you want the highest quality when it comes to solar panels for boats, then SunPower and Maxeon is the way to go, and this 50W flexible solar panel is no exception. With 2.8amps and with a good charge controller you can get this panel up to 45-50 watts every time.
- high-quality build
- highest efficiency in the industry 22-25%
- produces power even in cloudy days and partial shadows
- robust and flexible
Best budget 100W solar panel
This affordable 100W monocrystalline high-efficiency marine solar panel from HQST is another great choice as far as fixed solar panels go. It’s budget-friendly, yet performs nicely in low-light environments.
- high efficiency of 21%
- pretty good in low-light environments
- easy to install
Best solar panel kit for boat
An all-in-one solar power system, good for beginners. One of the best marine solar panel kits for the money. Built for reliability, this Renogy kit is easy to set up, durable, and has everything to get you started with solar.
- High efficiency of 21%
- easy and minimal to set up
- Controller can accept more panels
- keeps your batteries charged/cycling during the winter
Great value for the money
This affordable Newpowa marine solar panel is still highly efficient, durable, and does what it’s supposed to. These panels are proving to be an excellent long-term choice for sailboats, homes and RVs.
- high efficiency
- good performance in lower light conditions
- high quality construction
- good looking compact design
Best 25W solar panel for the money
Being only 25W, these Newpowa rigid solar panels are a great deal for this size, at only $1.56 per watt. Prices are dropping rapidly, but this is still great for such a small panel.
- can generate above 25W at full sunlight
- can provide above 1.4 amps
- quality in production and highest efficiency
- easy to install and very durable
Great bang for the buck
Renogy is well-known for good production, and this 100Watt solar panel is of pretty good quality in the realm of marine solar panels. Extremely popular, with very little downside.
- decent quality with high efficiency
- lighter, smaller, and sturdier than your average panel
- a good amount of power in cloudy weather
200W of Solar under $200
With sucWith such high-efficiency levels, these two WEIZE 100W solar panels can easily charge a decent deep cycle battery in a matter of hours and could be enough for most of your power needs.
- 21% efficiency
- good quality for the price
- 15.8lbs, accessories not included
Good value for a small panel
At only $1.43 per watt, these powerful little Newpowa solar panels are a great choice for a solar sailboat, as they can safely but surely lighten your power load.
- efficient, sturdy and quality build
- affordable and easy to add to an existing system
- high cell efficiency
What kind of marine solar panels to choose?
To get the best conversion and to catch most of the solar energy, consider getting rigid, fixed mounting solar panels. You can position them directly at the sun as you move around, and they have higher conversion rates compared to flexible solar panels.
If you’re unable to place those, then go for flexible solar panels, also called bendable solar panels, which have lower efficiency, but can be easier to place on some boats. Flexible solar panels require very little space because you can mount them almost anywhere. They are aerodynamic, which is a great choice if speed is important to you. On the downside, you’ll get slightly lower energy conversions.
There’s also the option of walkable solar panels, which are flexible solar panels on which you can walk. They can cover a larger area and are popular on narrowboats. The drawbacks are that it will also lower their lifespan a little, and they tend to be lower in wattage.
Mounting flexible solar panels can be an easy task for some, and daunting for others.
Here’s a great video to get you started:
Flexible solar panels for boats vs rigid
Here are the main differences between rigid and flexible solar panels:
Rigid solar panels are generally less expensive, more efficient at converting sun into electricity, and you can angle them at any time towards the sun to produce the most power.
Flexible solar panels are generally more expensive, and less efficient at converting energy, but you can place them on curved surfaces. You can walk on some of them.
Which one should you choose depends entirely on your needs, available space, and personal preference.
What components do you need for solar on a boat?
There are four main components in a marine solar panel system:
- solar panels
- charge controller
Solar panels absorb energy from the sunlight, and generate electricity, even in cloudy weather. The sunnier it is, and the better alignment of the solar panel towards the sun, the more electricity it produces.
Charge controllers prevent batteries from overcharging. We use them to regulate power input and deliver optimal power output.
Inverter converts direct current (DC) electricity into alternating current (AC) electricity. Most appliances and equipment today use AC power, so inverters are crucial in a solar power energy system.
Finally, batteries store energy from your solar panels for later use. For solar power, we usually use lead-acid deep-cycle batteries of different sizes. One thing to remember: try not to let your deep-cycle battery discharge below 50%, to maximize the number of future charge/discharge cycles.
You also need connecting cables to connect everything, and optional mounting brackets to install the panel and align it directly at the sun.
How to get the most out of your solar panels
- Keep your panels out of shadows. Even if only a small portion of the panel is in shadows, the output can drop a lot. Notice if your mast, radar scanner, or boom will cast shadows on your solar panels.
- Keep your panels pointed directly towards the sun. All panels will produce more power when they are getting direct sunlight. The more they’re misaligned the less power they generate.
- Keep your panels ventilated. Solar panels will get very hot in the sun, and high temperatures will lower their efficiency. Your panels will get nice ventilation when in the air, but consider using spacers when mounting on deck to allow airflow between panel and deck.
Solar panel power outputs relative to the sun
I’ve put together a simple table to show how solar panels perform under different amounts of light:
|Intensity (% of full sun)||Power Output|
|Full Sun - Panel pointed directly at sun||95-100%|
|Full Sun - Panel at 45° angle to sun||60-70%|
Of course, this will largely depend on the quality of your solar panel, but the numbers are constantly improving due to constant solar panel improvements. All in all, it’s always best to align your solar panels towards the sun to get the highest output.
Where to place solar panels on boats?
Common mounting locations for rigid panels are biminis, radar arches, lifelines, decks and hard tops. You can even put them on sticks, with a sturdy backing panel.
Flexible panels can be mounted almost anywhere due to their nature and can be held down with straps and bungee cords. You can place them on canvas dodgers and biminis, dinghy davits, and sail covers.
What size solar panel will charge a 12v 100Ah battery?
If your panel puts out a 100W that’s about 7A. Theoretically, it would take about 14-15 hours for a 100W solar panel to charge a completely discharged 100Ah battery. In a real-world scenario, you’ll be charging a 50% discharged battery. In this case, it would take about 8-10 hours for a 100W solar panel to charge a 50% discharged lead-acid deep-cycle 100Ah battery.
Depth of Discharge is crucial to battery life. Usually, your lead-acid deep-cycle battery shouldn’t go below 50% of discharge to maximize its lifespan. So the 14-15 hours is a theoretical timespan, given perfect conditions.
The bigger the panel, the faster it will charge a battery, but you also need to buy a higher current, such as a higher charge controller.
Here’s an interactive calculator to figure out how much solar power you need.
Real-world tips to reduce power consumption on a boat
Before adding more panels, try reducing your power consumption. Here are some tips on how to do so:
- Add insulation to your fridge. Fridges can use a lot of power because they work constantly. Extra insulation can reduce power consumption by 3-4 times.
- Don’t buy cheap Peltier element fridges. They don’t cool well and are huge power hogs.
- Get a decent solar charge controller, such as Victron MPPT controller, which is more expensive but has better efficiency and durability.
- Use LED lights. You can replace a standard 60W light bulb with one 6-7W LED light bulb. That’s 8-10 less power consumption.
- Measure how much power you need for navigation, and what can be used instead of your current electronics that use a lot of electricity.
- Make sure you have enough batteries to store all that power. No point in generating 300 Watts with nowhere to store it.