I stick by my small panels are better. Small panels can always be combined to fill a larger area. MPPT
controllers are a must on a vessel. You can't just throw away what little power you can get from your panels. My 60 Amp MPPT
controller doesn't have a fancy display, but it was only $80 on ebay from a place in CA. Smaller panels do not have thinner glass, which makes them less susceptible to breakage.
What I do need to do with my cheaper panels is replace the wires coming out of the junction box with marine
wire. Just a little soldering. After doing that, I will coat the contacts and the diode inside with epoxy
to protect them from the salt environment
(since the current
at full output is just 1.4 watts, the diode will not get very hot---and with the losses, it will not even be 1.4) Each panel has its own diode, so when shaded (or broken), it doesn't become a 'load' on the whole system. Yes, panels become a drain when not working putting out voltage--hence the diodes on each panel.
All monos available today are 18% efficient or better. Getting the best at 22% might not make that much of a difference. Poly has always been wrong for a boat. Efficiencies have never been good enough. No matter what: 100 watts is 100 watts. It is the only way to compare. Every panel is going to have losses for cloud cover, angle of incidence (direction to the Sun), and temperature. All mono cells are made of the same thing, and made pretty much the same way (my Dad was a semiconductor device man) The significant differences between panels is between mono, poly, and thin film. While the losses might differ by a few percent would it be worth twice the price
? You could look for 'solar' glass, which transmits more energy through the glass. Start with mono, modify as needed. My panels were $1.46 per watt delivered. Mounting and wiring
extra, of course. Price
was my main concern. With my catamaran
roof, area was less a concern.
Most important is efficiency of use. Everything must be LED (with voltage spike protection). Spend the extra to get lights that use less power. Incandescent anchor
lights are 10 watts. LED run 1 to 4 watts for the same thing. Get as close to 1 watt as possible. Use less, and the power from the panels will go farther. Do this everywhere. It adds up.
As for books
on the subject, try Amazon. I have 'The Solar
Boat Book' A little outdated, but a good read. Get more than one book. Take from each what will work for you. No one has all the answers for everyone in one place.