That is connecting solar panels in parallel increases the available current of the system, so two identical panels connected in parallel will produce double the current as compared to just one single panel. But while the currents add up, the panel voltage stays the same.
Most residential solar panels are connected in series. When you connect solar panels in series, the voltage adds up, but the current stays the same. You can get away with smaller wiring and have a long run between the panel and the inverter without much loss of electricity.
But you need to ensure the cable from the combiner box to the solar controller is of a sufficient gauge to carry the higher current. Yes, this will increase the amps of the output from the combiner box. The voltage will be 2 x single panel voltage, while the current will be 3 x the single panel current. It's the same arrangement I have.
Here’s an example: If an inverter has a maximum input voltage of 600V and each panel produces 40V, you could connect up to 15 panels in series (15 x 40V = 600V). Going over this voltage limit can harm the inverter or make it shut down, making your solar system less effective or even unusable. Equally important is the minimum input voltage.
This parallel combination produces 12 volts DC at 9.0 amperes, generating a maximum of 108 watts. Again the total output current, ITwill be the sum of the individual panels which will depend on the number of connected panels. As before the output voltage remains the same at 12 volts.
While individual solar cells can be interconnected together within a single PV panel, solar photovoltaic panels can themselves be connected together in parallel strings to form an array of interconnected panels increasing the total available power output for a particular solar application compared to a single panel.