Most inverter manufacturers offer Web-based system configuration tools to help determine the number of specific modules that can be connected to a particular inverter. You input the PV module model, inverter model, and high and low ambient temperatures for your area, and it provides you with different possible configurations you can use—the number of modules in series, and the number of series strings in parallel—to match the inverter’s specifications.
The example’s results show three options:
- Three series strings of 8, 9, 10, or 11 modules each (although, at about 4.3 kW of output, an array with 8-module strings is well below the 6 kW inverter rating).
- Four strings of 8, 9, or 10 modules each.
- Five strings of 8 modules each (in some cool climates, this array output, as well as one with four strings of 10 modules each, will exceed the inverter’s rating resulting in occasional power clipping).
These tools can be very useful, but care should always be taken to double-check the results by hand-calculations, using the manufacturer’s specifications and appropriate parameters, before a final design is reached.