The PVWatts performance model displays the following results in Tables and Time Series graphs. For details about how the model calculates these results, see Dobos, A. (2014). PVWatts Version 5 Manual (PDF 714 KB).
Variable Name |
Units |
Description |
|---|---|---|
AC inverter power |
W |
The output power of the inverter(s) |
Ambient temperature |
ºC |
Ambient temperature (dry-bulb) from the weather file |
Angle of incidence |
degrees |
The angle between the beam irradiance and a line normal to the photovoltaic array surface. |
Beam irradiance |
W/m2 |
Direct normal solar irradiance data from the weather file |
DC array power |
W |
The output power of the photovoltaic array |
Diffuse irradiance |
W/m2 |
Diffuse horizontal solar irradiance data from the weather file |
Global horizontal irradiance |
W/m2 |
Global horizontal solar irradiance data from the weather file |
Module temperature |
ºC |
Operating temperature of the photovoltaic cells in the modules |
Plane of array irradiance |
W/m2 |
Solar irradiance incident on the photovoltaic array |
Power generated by system |
kW |
The output power of the system (equal to the AC inverter power converted from W to kW) |
Shading factor for beam radiation |
- |
Factor applied to beam irradiance to represent reduction due to shading |
Sun up over horizon |
- |
Indicates whether the sun is up for the given time step (1 = sun over horizon, 0 = sun below horizon) |
Transmitted plane of array irradiance |
W/m2 |
Plane of array irradiance transmitted through the module cover to the photovoltaic cells |
Wind speed |
m/s |
Wind speed data from the weather file |
Variable Name |
Units |
Description |
|---|---|---|
Monthly DC energy |
kWh |
Monthly total of hourly array DC output. |
Monthly AC energy |
kWh |
Monthly total of hourly inverter AC output. |
Monthly AC energy in Year 1 |
kWh |
Monthly total of hourly inverter AC output. This is the same as Monthly AC Energy. |
