Simulation variables: Grid system |
  
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Simulation variables: Grid system |
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The following variables are calculated during the simulation process, and available as results:
Meteo and irradiation variables: see previous page.
PV array behavior
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PNomArray |
Nominal Installed Power |
( = Nb. PV modules * nameplate PNom) |
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EArrRef |
Array reference energy for PR calculation
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= GlobInc * PNomArray |
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EArrNom |
Array nominal energy at STC, according to the
one-diode model |
= GlobEff * Pmpp (STC) |
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GIncLoss |
PV loss due to irradiance level |
(low-light efficiency) |
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TempLoss |
PV loss due to temperature |
(see Uc and UV parameters) |
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SpctCor |
Spectral correction |
(amorphous modules, CdTe, Sandia model) |
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LigSoak |
Light soaking for CIS/CIGS modules |
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ShdElec |
Electrical loss for mismatch due to shadings |
(calculation "according to module strings" or "ModuleLayout") |
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ModQual |
Module quality loss |
(users choice concerning real performance of the modules) |
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LIDLoss |
Light Induced degradation |
(for mono-crystalline modules, p-type wafer only) |
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MisLoss |
Module array mismatch loss |
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OhmLoss |
Ohmic wiring loss in the DC array |
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EArrMPP |
Array MPP energy after all array losses |
(on the loss diagram) |
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Effective energy at the array output |
(taking inverter operating point displacements into account - not represented on the Loss diagram) |
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Iarray |
Array current |
(taking inverter operating point displacements into account) |
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Uarray |
Array voltage |
(taking inverter operating point displacements into account) |
Inverter behavior (see also Inverter operating limits)
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InvLoss |
Global inverter loss |
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IL Oper |
Inverter Loss during operation |
(efficiency curve) |
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IL Pmin |
Inverter Loss due to power threshold |
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IL Pmax |
Inverter Loss due to power overload |
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IL Vmin |
Inverter Loss due to low voltage MPP window |
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IL Vmax |
Inverter Loss due to upper voltage MPP window |
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IL Night |
Inverter night energy |
(usually negligible or null) |
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Syst ON |
System operating duration |
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EOutInv |
Available Energy at Inverter Output |
Energy output and use
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Aux_Lss |
Auxiliaries consumption |
(Fans, other... ) |
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EacOhmL |
AC ohmic loss |
(wiring up to injection point) |
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ETrfLss |
External transfo loss |
(iron loss and ohmic contribution) |
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UnavLss |
System Unavailability loss |
Specified or random periods of shutdown |
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E_Solar |
Energy supplied to the user from solar |
if load is defined (Netmetering) |
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E_User |
Energy need of the user |
if load is defined (Netmetering) |
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E_Avail |
Energy available from the sun |
= EOutInv - losses after inverter (Wiring, night losses) |
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Energy injected into the grid |
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EApGrid |
Apparent energy into the grid |
when Power factor defined |
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ERegrid |
Reactive energy into grid |
when Power factor defined |
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SolFrac |
Solar fraction |
ESolar / EUser |
Efficiencies
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EffArrR |
Array Efficiency |
EArray / rough area |
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EffArrC |
Array Efficiency |
EArray / cells area (=0 when cells area not defined) |
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EffSyR |
System efficiency |
EOutInv / rough area |
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EffSyC |
System efficiency |
EOutInv / cells area. |
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EffInvB |
Inverter efficiency |
Threshold loss included |
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EffInvR |
Inverter efficiency |
When operating |
Normalised performance index (cf IEC EN 61724, usually expressed and plotted as values per day)
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Yr or |
Reference Incident Energy in collector plane |
= GlobInc [kWh/m²] (kWh irradiance) |
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Yr |
Normalized Reference nominal energy at STC |
= EArrRef / PNomArray [kWh/kWp] (kWh electrical) |
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Ya |
Normalized Array Production |
= EArray / PNomArray [kWh/kWp] |
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Yf |
Normalized System Production |
= EGrid or EAvail / PNomArray [kWh/kWp] |
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Lc |
Normalized Array Losses |
= Yr - Ya |
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Ls |
Normalized System Losses |
= Ya - Yf |
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PR |
Performance Ratio |
= Yf / Yr = E_Grid / (GlobInc * PNomArray) |
NB: The Normalized Reference nominal energy at STC Yr [kWhel/kWp] is the electrical energy which would be produced by the Reference incident energy on the collector plane under STC conditions (1 kWirrad/m2, 25°C). This explains that the values are identical.