Like many boating and yacht enthusiasts, you might be looking for a way to reduce your ecological footprint while saving money at the same time. One great way to do this, particularly for Florida boaters, is to install solar panels on your boat. This can be an especially huge convenience for sailing enthusiasts, as it provides a reliable, fuel-free power source for your adventures.
Solar panels help charge the house batteries while anchored or sitting on a mooring, ultimately reducing or eliminating the need to run a generator. This reduces fuel consumption, and assures that you won’t get stuck with an empty tank and a dead battery on longer outings.
With correct installation, sizing, and positioning of solar panels, you could realistically offset a significant portion of your boat’s operating costs. Setting up a solar system on your boat doesn’t have to be troublesome or expensive; solar panels are now more efficient and affordable than they ever have been, and are no real challenge for a do-it-yourself boater to set up.
Some Benefits of Using Solar Energy
- Reduce impact on environment while lowering boating costs by reducing or eliminating the need for traditional fuels
- Fuel-free unplugged power source that runs silently and produces no heat while generating energy
- Can fulfill power needs without the disruption associated with running your generator or motor
- In the hot summer months, won’t have to worry about your cooling needs, because panels won’t heat up your cabin like a diesel engine will
- Fewer concerns about finding the next electrical outlet, or running out of fuel to power your motor or generator
- Tailor your solar system to fit your particular needs and budget-be as energy independent as you’d like-can be expanded easily
- Addition or alternative to wind power
Creating a Charge: How Solar Panels Work
- Sunlight engages the solar cell, and activates the electrons on its surface
- The electrons bounce around creating an electrical chain reaction in the form of a DC charge
- The energy created is harvested and stored in batteries
- A charge controller regulates the flow of energy into the battery, and prevents overcharging
Next, energy stored in the batteries is used to run 12vDC appliances (lights, pumps, fans, etc.), and also 120vAC appliances through the use of an inverter. An inverter is a separate unit that transforms the 12vDC current coming out of the battery into 120vAC for use with most appliances (microwave, TV, radio, etc.). See a diagram of this entire process here.
Your Electrical Load
A good place to start when considering installing solar panels is to determine your daily energy requirement, and just how much of that electrical load you want your solar system to satisfy. To get an idea of your daily energy requirement, find the current draw of each appliance at 12vDC or 24vAC, and estimate how long each appliance will run during a 24-hr period. This will give you your daily amp-hour requirement. For a handy worksheet designed by West Marine just for this, click here. To figure out your energy needs measured in watt hours, simply multiply the voltage times the current (amperage). Then, estimate how long each appliance runs per day to find watt hours required per day.
A 100-watt solar panel should generate about 100 watt hours after an hour of full sunlight. In Florida, you can expect to get an average of 5.6 hours of full sunlight each day, which would generate about 560 watt hours per day or 3,920 watt hours each week (100 x 7 x 5.6).
Two Main Choices: Crystalline or Thin Film
Crystalline silicon (c-Si) solar cells are made of thick, rigid monocrystalline or multicrystalline silicon, last longer and are more efficient than the more lightweight thin-film versions. Also less expensive, thin-film panels are made with amorphous silicon (a-Si) and thin-film silicon (TF-Si), and are about 50% as efficient per unit area as crystalline. Despite their lower efficiency, thin-film solar cells are more reactive under low-light conditions and offer more convenient, flexible mounting options.
Where to Place Your Panels
When choosing a place to mount and install your solar panels, your main concern should be keeping them away from anything which might cast any unnecessary shadow on them. This means staying well away from things like the radar dome, flagstaff, sails, and other similar structures. You might consider the Bimini top, coachroof, radar arch, and deck as good options.
Keep in mind that you will not be able to walk on your solar panels due to their tempered glass surfaces, and they will need to be kept clear of dust and dirt, as this lowers their output. Also, make sure your solar panels have space underneath them for air circulation to prevent buildup of excess heat.
Expanding Later
If you are like many marine explorers, you may want to start small and see how your solar energy experience goes before further expanding the system. Luckily, upgrading and expanding your solar system can be done without regard to size or brand of additional panels.
For example, if you currently have a 100-watt panel, it is possible to add an additional 50-watt panel by connecting them together within the same system. The only two things you will need to make sure of are that the voltage of the panels match and that your controller is powerful enough to handle the total output of the solar system. If you have a 10-amp controller that has a maximum input of 150 watts, your total output would not be able to exceed that.
