Simulation in PV, is always as good as the real thing…

A PV plan made of 450-polycrystalline modules, 220 Wp each with a final anticipated capacity of 99 kWp in location 40 km away from Lamia, Fthiotis Greece. We performed more detailed simulation with one of the most popular simulation software for PV, Pvsyst and we are going to present our results compare to the real PV plan’s performance.

But first lets say a few words about this project constructed by Alfa Energy.

PV Plan info:

Module type: 450 x Conergy Power Plus 220 P – 220 Wp
Inverter type: 9 x SMA SMC 11000TL
Monitoring:    SMA Webbox
Pane tilt: 28o
Azimuth: 0

Simulations info:

Meteo data: PVGIS Climate SAF

Module type: 450 x Conergy Power Plus 220 P – 220 Wp
Inverter type: 11 x SMA SMC 11000TL
Pane tilt: 28o
Azimuth: 0
Const. Loss factor Uc: 29 W/m2k
Wind loss factor Uv: 0 W/m2k/m/s
NOCT coefficient: 45 C
Ohmic losses: 1%
Mismatch losses Power loss at MPP: 2%
Near Shading: According to Module Strings

Results

PV real production was  4,73 % more than simulations results. With a performance ratio 0.822. We also noticed that from February till May real production was 7%-11% less than simulation’s results and from June till January 5%-20% more than simulation’s results. Engineers suggest that PVGIS classic is more reliable, through our point of view is just safer! Also very important parameter is NOCT coefficient, for 56 C NOCT (default from Pvsyst) real production was bigger 8,59 % almost 4%.