Simulation variables: weather data and irradiations
The following variables are calculated during the simulation process, and available as results:
Weather data
GlobHor | Horizontal global irradiation | as read on the weather data file |
DiffHor | Horizontal diffuse irradiation | read on the weather data file |
BeamHor | Horizontal beam irradiation | = GlobHor-DiffHor |
Tamb | Ambient temperature | read on weather data file |
Windvel | Wind velocity If not present on file: | read on weather data file monthly value, or default value (1.5m/s) |
Incident energy in the collector plane (result of the transposition)
GlobInc | Incident global irradiation in the collector plane |
BeamInc | Incident beam irradiation in the collector plane |
DiffAInc | Incident diffuse irradiation in the collector plane (usual "diffuse" acception including albedo) |
DiffSInc | Incident diffuse irradiation (from sky) in the collector plane |
AlbInc | Incident albedo irradiation in the collector plane |
Secondary indicators
Bm/Gl | Incident Beam/Global ratio | = BeamInc / GlobInc |
Diff/Gl | Incident Diffuse/Global ratio | = DiffInc / GlobInc |
DifS/Gl | Incident Sky diffuse/Global ratio | = DifSInc / GlobInc |
Alb/Gl | Incident Albedo/Global ratio | = AlbInc / GlobInc |
Incident energy on collectors, corrected for optical losses
GlobHrz | Global on collectors, corrected for horizon (far shadings) |
GlobShd | Global on collectors, corrected for horizon and near shadings |
GlobIAM | Global on collectors, corrected for horizon, near shadings and IAM |
GlobSlg | Global on collectors, corrected for horizon, near shadings, IAM and soiling |
GlobEff | "Effective" global, after all optical losses (shadings, IAM, soiling) |
DiffEff | "Effective" diffuse, corrected for all optical losses "Effective" = irradiation effectively reaching the PV-cell surface. |
Secondary optical factors (the factors for Diffuse and Albedo are constant)
FTransp | Transposition factor | = GlobInc / GlobHor |
FHrzBm | Horizon shading factor on beam | = BeamHrz / BeamInc |
FHrzGl | Horizon shading factor on global | = GlobHrz / GlobInc |
FShdBm | Near shading factor on beam | = BeamShd / BeamHrz |
FShdGl | Near shadings factor on global | = GlobShd / GlobHrz |
FIAMBm | IAM factor on beam component | = BeamIAM / BeamShd |
FIAMGl | IAM factor on global component | = GlobIAM / GlobShd |
FSlgBm | Soiling loss factor on beam | = BeamSlg / BeamIAM |
FSlgGl | Soiling loss factor on global | = GlobSlg / GlobIAM |
Specific variables for bi-facial systems simulation
GlobGnd | Global incident on ground, below the system. |
ReflLss | Ground reflection loss (albedo) |
BkVFLss | Loss due to the view Factor for rear side |
BackShd | Shading loss on the rear side (mechanical structures between ground and rear side) |
DifSBak | Sky diffuse directly reaching the rear side |
BmIncBk | Beam incident on the rear side (morning/evening in Summer) |
BmSFBak | Beam shading factor on the rear side |
BeamBak | Beam effective (after shadings) on the rear side |
GlobBak | Global irradiance on the rear side |
ReflFrt | Ground reflection on the Front side (added to GlobEff) |
PV array virtual productions for loss evaluations
EArrRef | Array Reference Energy for the PR evaluation. Virtual energy produced according to the manufacturer specification Pnom (nameplate) The reference installed power is equal to PNom (nameplate) * Number of PV modules. Equivalent to the Yr normalised value. Not shown on the report. |
EArrNom | Array Nominal energy at STC, starting point for the loss diagram Virtual energy produced at TRef (STC: 25°C) according to the PV model This may differs from the preceding as it is based on the model's Pmpp result instead of PNom, which may be slightly different. |
PV array losses and MPP running
GIncLss | PV loss due to irradiance level This is the effect of the low-light efficiency of the PV module (efficiency with respect to effic. at 1000 W/m2) |
TempLss | PV loss due to array temperature Difference E(GlobEff, TMod) with respect to model calculated at Tmodule = 25°C |
SpctCor | Spectral correction (for amorphous or CdTe modules) Calculated from the Spectral correction model amorphous) or the specific model from FirstSolar for CdTe. |
ModQual | Module Quality loss fixed constant parameter, |
MisLoss | Module mismatch loss fixed constant parameter for MPP or fixed V operation, depending on system, |
OhmLoss | Ohmic wiring loss, calculated at each hour with the real array current |
EArrMPP | Array virtual energy at MPP (after wiring and mismatch losses), Virtual calculation independent of the system running (inverter, regulator) |
Tarray | Average module temperature during operation |
DTArr | Temperature difference between modules and ambient' |
DTArrGl | DTArr weighted by "effective" global' irradiation |
TExtON | Average ambient temperature during system operation. |
Further simulation variables are system-dependent: