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Renewable energy is no longer just a concept; it is a part of our daily lives. The solar energy industry has made more advancements in efficiencies than any other form of renewable energy, and boaters are increasingly taking advantage of this progress due to solar’s ease of installation and integration aboard trawlers. When harnessed correctly, that beautiful sun we enjoy boating under is packed with energy that will keep our generators quiet for countless hours. This peacefulness is also no minor offset to the cost of boating, when fully calculated, the cost of running a fossil-fueled engine just to produce electricity is quite high. Even a modest solar panel set up will provide a reasonable return on the investment.
There are boat manufacturers working on exciting designs that use solar power to provide energy for slow-speed propulsion, however, our focus here is on understanding how solar can supplement your power while at anchor or when shore power is unavailable.
In layman’s terms: Solar power is generated by converting energy from the sun into DC electricity through the photovoltaic (PV) process. The solar panel absorbs photons of visible light, generating an output of electrons. These electrons are then gathered into DC electricity. With no conversion and only a simple regulation process necessary, it’s easy to feed the DC current from the solar panels directly into the boat’s battery bank.
The two types of solar panels primarily installed on boats are crystalline silicon cell panels, which consist of a collection of individual PV cells, and thin-film panels, which are flexible sheets coated with a semi-conductive PV material.
Crystalline silicon cell panels are typically in a rigid configuration with an aluminum frame with glass covers, but also can be built on a semi-flexible stainless steel or fiberglass sheet, this method will allow a small amount of flexing, typically around 3 percent. These are not to be confused with truly flexible, thin-film, panels.
Crystalline silicon cell panels are made of either high-grade monocrystalline or lower cost polycrystalline silicon wafers. Panels made of crystalline silicon are rigid or only semi-flexible because the individual silicon cells are brittle and cannot bend. Due to the breakable glass covers on rigid solar panels, finding an out-of-the-way place to install them is critical because of the inability to walk on these types of panels. Most of the semiflexible type will allow you to walk on them.
Crystalline silicon cell panels have multiple PV cells wired together, with each cell adding to the total amount of power the panel will produce. Panels commonly available to boaters today will vary from 36 to 60 PV cells per panel. A panel with more or larger cells will produce more power.
In the case of thin film panels, “thin” refers to the type and application of the PV material, and not necessarily the overall thickness of the panel. Unlike crystalline silicon panels, a thinfilm panel consists of a layer or multiple layers of a PV material, the most common of which is amorphous silicon, applied to a flexible plastic sheet. The resulting panel is highly flexible, allowing it to conform to radiuses and uneven surfaces. Thinfilm panels are also much lighter in weight.
The primary application for solar energy aboard is to employ the DC electricity produced to help maintain a charge in the house batteries which power your onboard amenities.
Depending on the size of the boat, the house battery bank, and the type of creature comforts installed onboard, it may be possible to supply all of the boat’s electricity needs—or at least