How are PV modules rated compared to inverters?

PV modules are rated under standard conditions and generate DC energy, while inverters convert DC to AC energy. So, the PV system's capacity is measured either in MWDC by adding up all module capacities or in MWAC by adding up all inverter capacities. The ratio between these capacities is called the inverter loading ratio (ILR).

What is rated capacity in a PV system?

In a PV system, the rated capacity can be reported based on either all its modules or all its inverters. PV modules are rated under standard conditions and generate DC energy, while inverters convert DC to AC energy.

What is PV module capacity & solar inverter capacity ratio?

The PV module capacity and solar inverter capacity ratio are commonly referred to as capacity ratio. Reasonable capacity ratio design needs to be considered comprehensively in the light of the specific project.

What is the rated capacity of a solar PV system?

It is expressed as a ratio, measuring the annual average energy production of a solar PV system relative to its theoretical maximum annual energy production. For PV systems, the rated capacity is typically aggregated either in terms of all modules’ capacities or all inverters’ capacities.

Do higher DC/AC ratios improve inverter utilization?

Higher DC:AC ratios always improve inverter utilization and the capacity factor. The measurement of inverter utilization is capacity factor—the ratio between actual and maximum energy production. A significant portion of system cost is tied to the AC rating of the inverter (string or microinverter).

How does inverter loading ratio affect PV capacity factor?

The ratio between these capacities, known as the inverter loading ratio (ILR), profoundly influences the calculation of the capacity factor. Thus, a PV capacity factor calculated using a DC-rated capacity has a higher denominator and, thus, a lower ratio than a PV capacity factor calculated using an AC-rated capacity.