There may be nothing wrong. However, a better understanding of the system rating or sizing may clarify.
Hopefully this helps:
Modules are tested in laboratory conditions and are rated in direct current as that is the current that is produced by the modules. The current we use for our homes is alternating current. There are many things that affect solar access which affect the final AC output; such as: the tilt of the roof, shading that may be present, angle of modules facing the sun, dust or debris on the modules, geographic location, time of year, inversion loss (conversion from DC to AC), etc.
Manufacturers rate modules in laboratory conditions and solar companies present PV systems based on the number of modules times the rating set by the manufacturer. For instance, a 4.125kW PV system consists of 15 modules rated at 275w (15 X 275w = 4125w = 4.125kW). Although the PV system is rated in direct current, your usage is measured after inversion to alternating current – which is less based on the variables (we’d have to guess at the time of the presentation as to the rating in alternating current).