A Solar Array is a group of solar panels that are connected together, collectively converting solar radiation into electricity. What sizes of solar array are common? Solar array sizes can vary from two small solar panels connected in a string to a MW power plant. A typical solar array is composed of one type of solar panels, as this is the optimum configuration. How are solar panels connected? A solar array is a string of solar panels connected in series. The solar panels are usually connected with solar cable and MC4 connectors. The maximum number of solar panels per string depends on the actual input voltage of the solar inverter. Usually not more than 20 solar panels are connected in one string, even though the latest solar inverter models allow more solar panles to be connected per string.