Originally Posted by AFKASAP
I am about to add solar panels
to my boat. I have been speaking to many boats in the various anchorages
I am visiting in Mallorca. I am surprised at how many people are not very happy with the performance of their solar systems.
Are you happy with yours, if so what setup do you have?
I am thinking of adding two 100 what panels. I will have to attach them to my gaurd wires next to the cockpit
for the time being as I do not have an arch.
As others have said, watch out for shading, it is the biggest problem for solar. I've watched our two 140 watt panels putting out 200 watts one moment, then drop like a rock to 90 watts a minute later as the shadow of the windgen falls across them. Ours are up high at the stern, well clear of the mast
but bifurcated by the aft stay. Then they are also under threat from the wind generator
, and at low sun angles, the radar
Other than that, the actual size you choose depends on your energy needs. Do an energy budget
first, it may radically change your shopping
list. Sure, I am happy with 2 x 140 watt panels, but our energy needs are pretty trivial and we have a big windgen as part of the equation. Our energy needs may look nothing like the next boat.
MPPT controllers are nice for the extra power they can extract from larger panels, but they may be a pointless expense if your energy budget does not need them. Whatever controller you buy, try to find one that gives you flexibility with your battery
chemistry choices. That's one area I think is changing pretty fast at the moment. I chose a German design controller that had a whole stack of pre-programmed battery
chemistry settings, but, most important, had one programmable setting for an extra battery chemistry. Currently using the presets for AGMs, but that is likely to change at some stage.