When you wire in series there is just a single wire leading from the roof for each string.
How to wire 2 solar panels in series.
Nonetheless it is possible to wire them in parallel.
When a solar installer wires your solar panels in a series each panel is connected to the next in a string the total voltage of each solar panel is summed together but the amps of electrical current stay the same.
To wire two or more solar panels and batteries in series simply connect the positive terminal of solar panel or battery to the negative terminal of solar panel or battery and vise versa respectively as shown in the fig below.
Wiring solar panels in series.
The parallel connection allows to increase the current keeping the same voltage.
To solve this problem and to optimize the energy performance of the entire system it is advisable to wire two panels in series obtaining a doubling of the voltage and then wire in parallel the three pairs previously wired in series so as to have doubled the voltage and tripled the current.
When you connect the positive terminal of one panel to the negative terminal of another panel you create a series connection.
Stringing solar panels in series involves connecting each panel to the next in a line as illustrated in the left side of the diagram above.
One positive and one negative.
For more information visit the page how to wire solar panels in parallel.
When you connect two or more solar panels like this it becomes a pv source circuit.
Just like a battery solar panels have two terminals.
If we have two or more solar panels with the same voltage but with different current it is not possible to wire them in series.