Choosing the Right Solar Panels for Your Sailboat

For sailors, especially those with smaller sailboats, finding the right solar panel solution can be a challenge. Whether you’re living aboard or planning long cruising trips, running essential equipment like a fridge and electronics requires reliable, efficient power. However, space is at a premium, so you need to choose a solar panel that fits your sailboat's design, offers durability, and provides enough energy to meet your needs.

Why Solar Panels are Ideal for Sailboats

Solar power is an ideal energy source for sailboats, particularly smaller vessels. It’s quiet, renewable, and can be customized to suit different boats and energy requirements. However, with limited deck space, selecting the right solar panels can feel like a balancing act between power output, durability, and available space.

Understanding Your Power Needs

The first step in choosing the right solar panels for your sailboat is understanding your power consumption. You’ll need to calculate how much energy your essential devices consume daily. For most liveaboard sailors, this includes your refrigerator, lights, navigation equipment, and charging stations for electronics. Depending on the equipment you’re running, energy needs typically hover around 2,000 watt-hours per day for a moderate setup.

To meet this energy demand, solar panels are typically rated by their power output in watts (W). A 115W solar panel on an annual average generates about 575 watt-hours per day under normal conditions. We calculate this by multiplying the panel's wattage by 5 (115 watts × 5 hours = 575 Wh). This accounts for the fact that only a fraction of the day will generate peak output due to varying sunlight conditions.

In this case, to generate 2,000 watt-hours per day, you would need approximately four 115W panels (2,000 Wh ÷ 575 Wh per panel ≈ 3.5 panels). If your daily usage rises to 4,000 watt-hours, which can happen with more equipment or multiple people aboard, you would need at least seven 115W panels (4,000 Wh ÷ 575 Wh ≈ 7 panels) to ensure consistent power generation.

An example of why we multiply Watts by 5 to get Watt Hours

Space Limitations and Choosing the Right Solar Panels

Space is always a concern on smaller sailboats, so you’ll want to choose solar panels that maximize power without taking up too much room. Look for thin, low-profile panels that won’t interfere with the usability of your deck. Walkable solar panels are a great option for sailors who want to preserve deck space. These panels are designed to be durable and can withstand foot traffic, allowing you to step on them without worrying about damaging them or tripping over raised edges.

Durability is another critical factor. Marine environments are harsh, with exposure to saltwater, sun, and wind. You need a panel that’s built to last. Fiberglass composite panels, like the ones offered by Open Waters Solar, are excellent for these conditions. They’re resistant to cracking and built to handle the demands of life at sea. Read more about microcracking here. 

Dealing with Shading on your Sailboat

Shading is a significant issue on sailboats due to the various structures that create shadows, such as the mast, boom, and rigging. Shade can significantly reduce the performance of a solar panel, so it’s crucial to select panels that have built-in bypass diodes. These diodes help maintain efficiency by allowing the electricity to flow around the shaded areas, ensuring your panels continue to generate power even in partial shade.

Choosing the Right Location for Your Solar Panels

Placement of the solar panels on your sailboat is crucial. Most sailors opt to install panels on the cabin top, bimini, or even on an arch if they have one. Make sure you leave enough room for essential tasks like adjusting sails and moving around the deck.

Consider installing flexible panels that can conform to the curves of your boat’s surfaces. These panels are lightweight, easy to install, and don’t require drilling holes into your deck, which can be a concern for boat owners. Open Waters Solar offers flexible panels that are not only highly efficient but also walkable, making them a perfect choice for smaller boats.

Floating Solar: An Innovative Solution for Small Boats

If space is still an issue, you might consider floating solar panels as a solution. Open Waters Solar offers a 300-watt floating solar array that can be cast behind your boat when it’s anchored. This option is ideal for small to medium sailboats that don’t have the real estate for traditional solar installations. The floating array offers the same high-efficiency power generation without taking up any deck space, making it a practical and innovative option for sailors with space constraints.

Considering Your Battery and Electrical System

When installing solar panels on a sailboat, it’s also important to consider your boat’s battery capacity and electrical system. You’ll need to ensure your setup is compatible with your power needs. We’ll cover choosing the right marine battery in another post, but it's important to plan for enough storage to match your solar generation.

Final Thoughts

Choosing the right solar panels for your sailboat requires careful consideration of your energy needs, space limitations, and environmental conditions. Walkable, thin, and low-profile panels are ideal for preserving deck space while providing the necessary power for long voyages. Durable and efficient panels with bypass diodes are a must-have for any marine environment, especially when shading is a concern.

If space is a limiting factor, consider incorporating a floating solar solution like the one from Open Waters Solar. With the right setup, you can enjoy the freedom of sustainable, quiet energy while cruising the open seas.