Putting solar panels on your boat isn’t as difficult as it might look. In Part 2 of these series, we’re going to look at what panel to buy, the various options available, and where to set them up.
Working Out What Type of Panel to Buy
This dilemma naturally depends on how much space you have available. Since your space is probably fairly limited, it might be worth eliminating both the second and third generation, which are more environmentally friendly, and cheaper. However, their conversion efficiency is not sailor friendly. This decision is obviously a personal one. Second generation panels tolerate shade well, but first generation crystalline panels are generally more suitable for boat installation.
You can choose from the mono- and poly-crystalline species of first generation panels, but they only differ slightly in cost per Watt and efficiency. From a cost perspective, rigid beats flexible. Panels designed for household use are generally very cost-effective, but their frames have the tendency to rust a lot more quickly.
The Different Type of Panels Available
For sailors’ purposes, there are three types of panels you might consider:
- Amorphous: these panels are made by depositing silicon onto a substrate: a cheap process that produces flexible units, but requires large areas as the efficiency is pretty low. They are tolerant of lower light levels, however.
- Polycrystalline panels are made by fusing small pieces of silicon together. They work excellently in unobstructed sunlight, but their efficiency drops considerably, even in partial shade. Semi-flexible panels are available, which could easily be fitted to your coachroof.
- Monocrystalline panels use large individual pieces of silicon, and are generally the cheapest solution now. Semi-flexible monocrystalline panels are quite rare due to their fragile nature. They are affected by shade in the same way as polycrystalline panels.
Where To Put Your Panels
The panels should be fitted close to your battery bank and somewhere that’s completely free of shade.
If your vessel has davits, they can make a very good spot to mount a panel. Other options are the gantries at the stern, or on the pushpit. The panels should be as close to a right-angle to the sun as possible.
If you’re a weekend sailor who would like your panel to top up batteries on a mooring, buy a small rigid panel and tilt it to catch the sun’s rays for the majority of the day. Bear in mind that if you apply a constant high power to an already charged batter, it can damage your battery, even if you use a regulator. Try trickle charging using a panel Wattage of about 10% of the battery’s stated Amp-hours.
If you’re a liveaboard, or spend considerable lengths of time on board, mono- or polycrystalline panels will provide you with more power from the same area.
The next part in the series will cover how to draw up your personal solar panel specification and the losses involved in solar panel use.