There has been a lot of debate about series vs parallel connections. The performance when part of the array is in shadow is the important difference.
Unfortunately, there does not seem to be a definitive answer, as there is data and user experience that support both types of connections. The performance can be mathematically predicted, but there are so many shadow permutations and the maths becomes too difficult for a realistic model, at least for me.
My reading of the various pieces of evidence is that parallel just wins and this is how I have wired my panels, but there is still some doubt in my mind.
If you are going with parallel make sure there is room to install suitably sized cable. Parallel connection needs a very hefty wire size for this sized array, and sometimes this will just not physically fit. This can swing the balance in favour of series, where the wire size only needs to be about 1/2 the overall area.
One factor that influences the panels' performance under series connection, is how many bypass diodes has been internally fitted. This varies from zero (which is very bad for panel longevity) to 8 or more. The specifications for your panel are here (I think this is the correct panel):
Sharp don't list the number of bypass diodes that have been internally fitted. Often this means the panel does not have many, which would push me further into recommending a parallel connection.
If you do want to use a series connection, it worthwhile installing an additional bypass diode around each panel.
Just a word of warning . You mention the manufacturer has specified a maximum Voc of 65v. In this case the combined Voc of your panels is 59.2v so it is fine. However, many manufacturers specify a maximum input voltage. It is often assumed this must be the Voc of the panels, but this is not the case.
Voc is maximium voltage produced (with no current
flowing) under the test conditions. Solar panels
can produce a higher voltage than this in some instances.
It is very important never to exceed the maximium voltage rating of solar
controller. If you exceed the maximium current
rating most solar
controllers will self protect and no damage will be done, but even a brief over voltage situation will often instantly damage the controller. For this reason most manufacturers recomend that you choose an array Voc well below the maximum voltage input specification.
Edit: I note in this later post you state the maximum input voltage
is 65v (not Voc as in your first post)
Originally Posted by Bruce K
12v DC, but regulator
is Mppt so input voltage can be up to 65v.
As I mentioned above this is not the same as Voc. You should check exactly what the specifications say. If the max input voltage is 65v the controller may not suitable for series connection of your panels. At the very least I would double check with the controller manufacturer because you will be very close to the limit. If you get this wrong the controller will be damaged.