PVWatts Results

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).

Hourly Data

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

Monthly Data

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.