Reducing the inverter costs

Oversizing the connected PV system power allows for better adaptation of the DC yield to the nominal AC power of the inverter. This allows the use of an inverter with a lower nominal power and lower costs reducing the relative inverter costs in the overall system.

More favorable energy output when installing inverters in limited space

Inverters sometimes need to be installed in specific locations, either due to constraints from the owner or local electrical regulations. This may mean it would not always be possible to install as many inverters at a site as would be desired for a perfectly sized system. However, by oversizing PV systems, it may be possible to achieve almost the same annual energy output with fewer installed inverters. A 100 kWp PV system with 75 kW installed inverter power possibly generates only about 2% less energy each year than the same PV system with 100 kW installed inverter power. This means that there is only a ~2% lower energy output for a 25% reduction in inverter power.

With the Sunny Design software for system design you can determine different system layouts and have the effects on the energy output calculated.