tend to be constant voltage devices. The amperage tends to fluctuate significantly. Your panels voltage will vary significantly if there is shade on them, temperature variation (the lower then temp, the higher the output), light intensity and age of the panels. Now, by constant voltage, it means you solar panels will try to put out a certain voltage, regardless of whether the load can accept it or not. For instance most 12 volt batteries tend only be able to accept 15 volts for short periods of time before there internal resistance causes significant damage due to heat. They are much happier accepting something closert to 13.6 or so volts at increased amperage. So, if you have solar panels that are putting out 16 volts, your regulator
will tend to want to cut that down to the acceptance level of the battery
. So your 17 volts at 5.5 amps which would normally give you a 93.5 watt rating drops to 13.5 volts at 5.5 amps 72.25 watts. What an MPPT
(Maximum Power Point Tracking) controller will do for you is gove upi 6.8 or so amps at the same 13.5 volts. It does this over the entire voltage range.
A better question is when will the produce 17 volts as opposed to when they will not. Pretty much they have to be directly facing the sun, in relatively cool weather
with no clouds, or shade on them. You will see reduced output with a halyard
casting shade on your panels, when a cloud goes by, when it is very dusty or crusted with salt
You hit on the right installation
approach, connect them in series to increase the voltage. If you have an MPPT
, it will bring that voltage back inline with the load (12 or 24 volt systems, normally). The only thing you have to be aware of is, that most MPPT's have a limit to how much voltage they can handle. Typically arround 100 volts or so. With 4 17volt panels, this will not be an issue, 5 would be. If it is cold and bright enough, you will almost assuridly go above 100 volts, at which point the MPPT would shut down. This would give you no usable output.
In your scenario, you'd probably see something closer to 8 amps at 13.5 volts in the early hours. You'd see significantly more amps as solar noon approached.