Back on the boat in a few weeks and adding more solar
is the next project
set up -
4 x 85 watt panels
mounted 2 in series either side of the boom on the coachroof then paralleled into a single
20 amp PWM controller
Works OK. I get up to 18 amps when there is no shading from the boom or sails
onto one side or the other. With shading to one side i get total shutdown on that side ie from 18 amp to 9 amps. So not ideal underway which is when I need more juice.
Plan is to add an extra 2 x 100 watt panels
(one to each side of the boom again) and due to difficulty getting to the existing panel wiring
this will be kept separate.
So intended set up -
4 x 85 w panels changed to MPPT
controller (keep same wiring
of 2 in series to parallel)
2 x 100 w (19voc) panels into second MPPT
controller. (The ones im looking at have 3 strings of 36 cells per panel)
1. Is it worth changing the PWM controller to MPPT on the existing panels in the hopes of getting some gain when the boom shades one side?
2. Whats the best way to wire the new panels - series or parallel - given the shading issue I have? ie double the volts from in series in the hope the MPPt will be able to get some output from the shaded panels? Wiring this way will be harder than parallel logistically so I would want to see some gain to drill the extra holes etc
thanks for any thoughts or similar experiences