Solar panels, also known as photovoltaic cells, have evolved significantly in the past decade. With decreasing size and increasing efficiency, solar panels have become easier to install in non-traditional locations, leading to a decrease in overall installation costs. The growing awareness of climate change and the global energy crisis has convinced more yacht owners to consider installing solar panels on their vessels. But is it worth it? In this article, we will explore the factors to consider when installing solar panels on your yacht.

Reasons for Our Decision:

When we purchased our Newport 41 - "Kate" in 2008, we chose not to install solar panels. Cost was a consideration, but our biggest challenge was finding a suitable location for installation. As a sailboat, our deck space was limited, and we didn't want to mount them on the sides, a popular installation method. The mast, rigging, sails, and our wind generator cast shadows all day, leaving only one open space capable of supporting the two large 155-watt panels we were considering: the bimini top. We were uncertain if the bow design was strong enough to support the extra weight, and it was not in our cruising budget to upgrade the structure. So, with some trepidation, we set sail, believing we could live comfortably without them.

Foldable Solar Panels:

However, one year later, when our engine encountered major issues and we had to rely on a small generator to meet our moderate power needs, we reevaluated our decision. Since then, living aboard full-time has been a different experience.

Factors to Consider:

When it comes to installing solar panels on your boat, there are several variables to consider, including the frequency of boat usage, your sailing destinations, your budget, and the options for panel installation. However, the two key considerations are your daily energy requirements and battery capacity.

Daily Energy Requirements:

Each boat has different energy needs depending on its size, the installed navigation equipment and hardwired devices such as refrigeration, toilets, and freshwater systems, as well as the number of gadgets that need charging to keep the crew satisfied. Monitoring your energy consumption onboard for a week will give you a good average. It's advisable to add 15% to be safe.

Battery Capacity:

The size of your boat's battery bank is often overlooked when it comes to installing solar systems. However, it is crucial to match the output of your solar panel array with the storage capacity of the battery bank, measured in amp-hours. For example, if you have a 400-amp-hour battery capacity, ideally, you want to generate enough solar power to run all onboard systems and charge the batteries so that the systems can continue to operate throughout the night.

Boat Usage:

The electrical demands differ between those who use the boat on weekends or seasonally and those who live aboard full-time. A family will consume more electricity than an individual. Additionally, the sailing location and time of year will impact how many hours of sunlight you can harness, affecting the amount of power you can generate.

Budget:

Although the energy produced by solar panels is "free," there is an initial investment involved. If you are not a DIY enthusiast, this includes not only the panels themselves but also the wiring and assembly. Don't forget the charge controller, which acts as the brain, allowing you to monitor and maximize the power generation while protecting your batteries.

Materials and Quality:

Beware! Not all solar panels are manufactured to the same standards or with the same materials. This means that two panels with the same wattage can have significantly different voltage and current outputs, resulting in different prices. This is particularly crucial when comparing mono-crystalline and multi-crystalline panels (the former being more shade-sensitive but offering higher output per square inch, while the latter has lower output but less noticeable drop in shade) and rigid and flexible panels. Therefore, it is worth comparing specification sheets when purchasing solar panels to ensure you are getting value for your money.

Installation:

Considering how and where to install solar panels is crucial. Ideally, the panels should have maximum exposure to sunlight. Structures like masts, standing rigging, wind generators, radar arches, antennas, and sails all cast shadows, so finding a location with minimal interference is key.

The development of flexible and semi-rigid solar panels has provided yacht owners with more installation options. Lighter and more flexible panels can be sewn directly onto canvas, while some semi-rigid panels are considered sturdy enough to walk on, meaning they can be directly adhered to the deck. Some yacht owners choose to mount their rigid panels on movable brackets, allowing them to tilt the panels to follow the sun in the sky.

In our case, as mentioned earlier, we installed rigid solar panels on our bimini top. However, we ended up creating a more robust structure to support the weight of the panels. Therefore, when designing solar panel installations, a little imagination can go a long way.

The Pros and Cons of Solar Energy:

On the surface, it seems like there are no downsides to having solar panels on your boat. After all, they are hailed as passive, free, and clean energy sources. However, all technologies have some negative impacts on users and the environment. It's important to consider all aspects of the conversation, not just the ones that make us feel good.

Yes, solar panels can liberate you from reliance on fossil fuels to power generators or engines traditionally used to meet power demands. However, this doesn't mean you have no impact anymore. Manufacturing solar panels requires significant resources and energy, not to mention the fossil fuels required for transportation from manufacturer to retailer and to you. Therefore, where you buy and where it is produced makes a difference.

Yes, recent advancements in solar technology have led to widespread consumer adoption. However, this also comes at a cost.

Most solar panels have a lifespan of 25 years, during which their output remains stable for most of the time. Recently, there's been a trend to replace panels before their lifespan ends, taking advantage of the smaller footprint and higher efficiency of new panels. This means that these panels are unnecessarily discarded. While significant progress has been made in recycling old solar panels and reclaiming reusable resources, currently, 90% of discarded solar panels end up in landfills. The energy produced may be green, but the lifespan of solar panels falls significantly short of environmental requirements.

According to a report by the International Energy Agency in 2016, it is estimated that the US alone generates one million tons of discarded/used photovoltaic waste in the form of solar panels each year. These wastes contain valuable resources such as aluminum, copper, silicon, and silver.

The demand for silver could be at risk due to the production of solar panels. The Silver Institute releases an in-depth analysis report on global silver supply and demand each year. The latest report, published earlier this year, revealed that in both 2021 and 2022, global silver demand exceeded supply. The significant rise in silver purchases has reversed the surplus trend that had persisted for over a decade, leaving many investors concerned about the future. The demand for silver increased by 18% in 2022 alone. With the rapid production of electric vehicles and solar panels, silver usage across industries is skyrocketing to unprecedented levels.

In conclusion, installing solar panels on your yacht is undoubtedly a step in the right direction. It can reduce your reliance on burning fossil fuels, ensure better maintenance of your batteries for longer durations, decrease air and noise pollution by reducing your dependency on generators, and give you the freedom to explore remote destinations as you become increasingly self-sufficient. However, nothing comes for free, even solar energy. There are still many aspects to consider.