|Changing System Parameters| |DC Rating (0.5 to 1000 kW)| The
size of the PV system is the nameplate DC power rating. This is
determined by summing the PV module powers listed on the
nameplates on the backsides of the PV modules in units of watts
and then dividing by 1000 to convert to kilowatts (kW). The PV
module power ratings are for Standard Test Conditions (STC) of
1000 W/m2 solar irradiance and module temperature. The default
PV system size is 4 kW. This corresponds to a PV array area of
approximately 35 m2 Caution: To achieve proper results, the DC
rating input must be the nameplate DC power rating as described
above, and not based on other rating conditions, such as PVUSA
Test Conditions (PTC). PTC are defined as 1000 W/m2 plane-of-
array irradiance, 20oC ambient temperature, and 1 m/s wind
speed. PTC differs from standard test conditions (STC) in that
its test conditions of ambient temperature and wind speed will
result in a PV module temperature of about 50oC, instead of the
25oC for STC. Consequentl