[C320-list] Solar panels and shading

[ptormey at 4square.net]

Well, I think you really do need to check with the manufacturer. They'll have guidelines.

Internal to a panel the cells are wired both parallel and in series to achieve the voltage and amperage required (Power=Volts X AMPS). This also protects failed cells from blocking the output.
In the old days it was common for some cells to be dead at manufacturer and still perform within spec.

My own unit (Suaoki 100W 18V 12V Solar Panel Charge) is 12-18 volts with an XCSOURCE 30A 12V/24V Solar Charge Controller Solar Panel Battery Intelligent Regulator LD296
Works fine on cloudy days and great on sunny days I keep it on the 'flexed' over the Dodger which is, of course, under the boom.   It doesn't do any heavy lifting like refrigeration but keeps the batteries fresh.
IF I wanted more power I'd parallel another 12-18 volt panel and let the regulator do its job.

It's hard to express the affect of shade without a constant load, but your supplier should be able to put some parameters on it.

Here is a good (simple ) article on the subject
http://www.mpptsolar.com/en/solar-panels-in-parallel.html



Pat