The producibility of the system is calculated on the basis of data,
derivates from source of specified climate data, of the installation
site relative to the average monthly global of solar radiation
incident on horizontal surface.
The procedure for the calculation of the energy produced by the plant
takes into account the rated power, the angle of inclination and
azimuth of the PV generator, the losses on the PV generator
(resistive losses, losses due to the difference in temperature of the
modules, reflection and mismatching between strings), the efficiency
of the inverter, as well as the reflection coefficient of the ground
in front of the modules (albedo).
Therefore, the energy produced by the system on an annual basis (Ep,
y) is calculated as follows:
Ep,y [kWh] = Pnom * Irr * (1-Losses)
Where:
Pnom [kW] = Nominal power of system
Irr [kWh/m²] = Annual irradiation on the surface of the modules
Losses [%] = Power losses
The power losses are due to various factors. The following table
lists the loss factors used by the procedure for the calculation of
system producibility.