These different stringing configurations have different effects on the electrical current and voltage in the circuit. 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).
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). Just like a typical battery you may be familiar with, solar panels have positive and negative terminals.
The “solar panel string” is the most basic and important concept in solar panel wiring. This is simply several PV modules wired in series or parallel. Solar panels feature positive and negative terminals. Wiring solar panels in series means wiring the positive terminal of a module to the negative of the following, and so on for the whole string.
When stringing in series, the wire from the positive terminal of one solar panel is connected to the negative terminal of the next panel and so on. When stringing panels in series, each additional panel adds to the total voltage (V) of the string but the current (I) in the string remains the same.
Wiring solar panels together can be done with pre-installed wires at the modules, but extending the wiring to the inverter or service panel requires selecting the right wire. For rooftop PV installations, you can use the PV wire, known in Europe as TUV PV Wire or EN 50618 solar cable standard.
There are multiple ways to approach solar panel wiring. One of the key differences to understand is stringing solar panels in series versus stringing solar panels in parallel. These different stringing configurations have different effects on the electrical current and voltage in the circuit.