A 5 kW solar system in 2021 will typically have around 14 to 16 solar panels. With 330 W panels, we would use 16 panels. For the high efficiency, 370W panels, we would use 14 panels, which gives you a 5.18kW system. The panels are 1.7 mx 1 m in size. For a 5 kW system, we usually install the panels in 2 rows of 7 or 8 panels.
A 5kW solar system usually looks like the picture below once installed on your roof using high efficiency panels from LG. This is LG's NeON 2 panel:
In this 5 kW installation, we are using the new split cell panels from Trina Solar, so there are actually two rows of panels here, not 4:
For more information on a 5 kW solar system, see: Everything you need to know about a 5 kW solar system