Marine solar powers are becoming widely known as an alternative way to generate energy. In general, solar panels receive their power from the sun and don’t burn fossil fuels. When installing marine solar panels on your sailboat there are several things to consider beforehand. In any case, if you’re a long-passage cruiser it’s a great investment to do for your sailboat. Generally, solar energy tends to become more affordable these days and can provide adequate natural power so as to keep your sailboat’s batteries topped off, and not just that. When installing a solar panel on your sailboat you opt for an environmentally friendly option. In this article, I’m going to give you some details about solar panels and how to maintain and take care of them. Follow me!

Marine Solar Systems

In general, a solar power installation consists of two independent systems. The first one refers to charging the batteries. So, basically, the solar panels absorb sunlight and then convert it into electrical current. The current gets to the batteries through a solar charge controller or regulator. The charge controller is a basic component of the solar power system as it protects the batteries from being overcharged. Then the batteries store the energy that originated from the solar panels. In other words, when the battery has reached a full state of charge the controller will work as a gatekeeper. As a result, this limits the current flowing to the batteries from the solar panels. Moreover, this process maintains and protects the life of the battery.

The second system refers to providing 120-volt AC power for appliances and equipment that require energy to function. So, this energy charges 12vDC appliances such as fans, lights, and pumps. Furthermore, when an inverter is used then the energy can also charge 120vAC appliances like the radio, TV, microwave, satellite dish, etc. Lastly, the inverter transforms the 12vDC current that comes out of the battery into 120vAC in order to use with most appliances.

>>Also Read: Best Way To Charge Sailboat Batteries

Benefits of Having Marine Solar Panels on Your Boat

In general, marine solar panels keep your batteries topped off while you’re disconnected from shore power. So, when you’re anchored, your TV, laptop, cell phone, cabin, and navigation lights will have enough power to be charged. Additionally, you’ll be able to start your engine whenever you want to. Moreover, you can generate electricity even when you’re away from your sailboat, something that isn’t possible with generators as they require monitoring and manual operation. So, having solar panels means that you can produce usable electricity throughout the day.

You’ll be also saving money and time, even though a marine solar panel installation requires an upfront investment. But if you make this investment you’ll be then at ease in the long term. Moreover, you won’t have to purchase fuel on an ongoing basis for the marine generators. Another advantage is that solar panels are noiseless so you won’t be producing sound pollution while sailing out on the open waters. Last but not least, you’ll make an environmentally friendly choice by installing marine solar panels. This is because gasoline generators and fossil fuels harm and pollute the environment. But marine solar panels are 70% eco-friendly and are a better option for generating energy than fossil fuels.

Useful Information

Before installing marine solar panels on your sailboat the first step is to figure out how many panels you need for your boat’s power requirements. Installation is a key factor and counts as much as the best quality photovoltaic array does. In addition, in order to estimate your boat’s energy requirement you have to add up all the energy used by each device on board. You can do that by simply checking the badge on the appliance which will give you the power requirements in watts or amps. Keep in mind, to select a place where your solar panels get the maximum sunshine exposure and avoid possible shading.

Mounting

Common mounting locations for marine solar panels are bimini tops, davits, radar arches, and also deck mounting. When a solid metal framework is mounted on these areas then you ensure that you’ll get a more productive and rigid output. If you choose deck mounting you can use spacers in order to allow airflow between the panel and the deck. In addition, remember to use silicone for the holes made on the deck. You can mount flexible panels that are held down with straps or bungee cords on on almost any surface. Another option for mounting panels is to place them to the lifelines and this way their elevation process can be manually adjusted. Furthermore, they can also be mounted right on the deck by attaching them to a solid support frame or just by gluing them.

Shading

In general, shading has to be avoided as much as possible on marine solar panels in order to ensure better performance. When panels are mounted in series and placed on the sun’s side they ought to be connected into the same group. Otherwise, shading will reduce their power efficiency. But you can also mount solar panels in parallel to the opposite sides of the boat. This means that one panel will be facing the sun while the other won’t.

In any case, keep in mind that solar panels will produce energy even if they are not directly exposed to the sunlight. But their power output is proportional to the amount of light that gets to their surface. For example, If the panel gets half of the amount of light during full sunlight, then you should expect the panel to produce about half the amount of power. Lastly, a solar panel tends to generate from 50% to 70% of maximum output under a bright overcast day, but only 10% to 20% under a dark overcast.

Wiring

Generally, panels in series are wired all the way to the solar charge controller with a thin-gauge wire. Panels wired in parallel have additive current flowing but the voltage across them isn’t additive. As aforementioned, in case you think that your panels will be frequently exposed to shading then you should prefer the parallel installation. This is because if they’re wired in series the shading of a single panel will affect the output of all the others in the array.

Also, when wiring a set of PV panels in series the voltage current tends to increase significantly. But the current will remain the same. However, installation in parallel does exactly the opposite. Lastly, if you combine in series or in parallel panels you always have to rate the single feed cable. The cable has to suit the maximum current available of the solar output and minimize voltage drop. Likewise, the cable from the charge controller to the batteries has to be sized accordingly so as to suit the controller’s maximum output current.

>>Also Read: Best Marine Wind Turbine Generators For Boats

Charge Controller Specs

As above mentioned, a charge controller has to fit into the solar panels’ system so as to produce the maximum output. There are two basic types of charge controllers in the form of Pulse Width Modulation or Maximum Power Point Tracking. PWM charges the battery with the bulk, float, and absorb charge. On the other hand, the MPPT is basically a multi-stage charging. The conversion efficiency of MPPT is 30% higher in comparison with PWM. Also, PWM is a more cost-efficient and easily deployed solution for small power systems. MPPT contains many electronic components inside and is more complex than PWM.

Solar Panel Care

High-quality PV panels include built-in diode protection among each cell to prevent a shaded cell to spread and affect the productive cells. Furthermore, sometimes an internal blocking diode placed on the final output line is also used. This will protect the panel from polarity reversal and will ensure that the batteries won’t discharge back into the panel. In addition, don’t omit to install a fuse and place it between each panel and the charge controller. Also, consider installing another fuse between the batteries and the regulator’s output. If you have a multiple panel array, then the second fuse has to be placed higher than the other panel fuses.

If you apply these protection steps then you’ll be able to connect other devices in parallel to the battery. Like this, you can charge your devices as well as leave the charger operating even while being anchored. However, in some cases, this arrangement might affect the battery and cause it to fall back into float mode. In case you notice this then you ought to install a manual switch so as to disconnect the solar array when you’re onshore power.

Solar Panel Care Tips

• In case you deal with harsh weather conditions always make sure to check the panels afterward. This is because in case the panels break down then their performance will be significantly affected.
• Look for dirt and debris increase on the panels’ surface. You can remove all that with a simple rinse off by simply using a hose.
• Look out for leaks and penetrations to the bolt and racking. In general, racking ensures the mounting safety of your solar system. The bolt penetrations hold the weight of the panels and ensure structural soundness.
• Remember to avoid shading as energy production becomes inefficient when they’re not absorbing sunlight.
• Try to record your panels’ performance so as to ameliorate solar panel maintenance. 
• When monitoring the system you’ll be able to see how much CO2 you are emitting into the atmosphere. 
• Consider buying solar panel cleaning kits which are quite practical for more efficient cleaning.
• Never use harsh materials, abrasive sponge, or chemical soap for cleaning the panels. This might cause them damage and panels are quite expensive to repair.

The Bottom Line

Installing marine solar panels on your boat is a great choice to make. Generally, depending on the size of your PV panels, they can maintain, charge the batteries, and produce sufficient energy to power both appliances and batteries. If you decide to install marine solar panels on your sailboat you’ll benefit from having durable batteries as well as saving some costs in the long-term. Also, you’ll be a “green” and responsible sailor who benefits from having natural electric energy on board. Taking care of marine solar panels is not a difficult task to perform. Solar panels don’t have moving parts and are easy to clean and maintain. I hope that I covered your questions about marine solar panel care and wish you a responsible voyage ahead!