Join Date: Sep 2004
Thanked 28 Times in 19 Posts
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I agree with the posts above re doing a useage budget, but rather than attempt to meet all your electrical needs with solar, why not figure out how many panels you can reasonable put on the boat and find other sources for whatever additional power you need (e.g. wind vane, genset or small gas powered generator).
Panels can be installed easily on dodger tops, quarter rails (you'll need more than lifelines to mount them on), and stern davits/arches (if you have them). Once you go beyond these locations the boat probably begin to look like a floating solar power station. I've seen a few and, believe me, it's not pretty.
In my experience, lights, fans (you'll need several in the Caribbean), frig/freezer, pumps and electronics (chartplotters, radios, computer, etc.) demand more than my small dodger-top, fixed-mount solar installation can deliver. On a sunny day at 10-20 degrees N we can generate 7 amps from two 50 watt panels for 4-6 hours a day -- hardly enough to run the boat, but certainly enough to cut down on engine/genset hours. We have a friend who has about 240 watts installed in two panels, P & S on the quarter rails. He, too, finds that the panels have significantly reduced, but not totally eliminated, generator hours.
Economics of panels are OK -- capital costs are high, but I've found the ammortized cost per amp hour delivered of the panel installation is roughly equal to the operating cost (fuel, oil, etc) of the genset.