Which one is POA value from PVsyst Results Raw data?

[Mike99]

Hi everyone,

I'm just trying to understand which irradiance value is actually representing the POA irradiance from the simulation result raw data below. Is it GlobInc column or I need to calculate it?

date	GlobInc	GlobEff	EArray	E_Grid	PR	GlobHor	DiffHor	T_Amb	WindVel	BeamHor
	W/m²	W/m²	kW	kW	ratio	W/m²	W/m²	°C	m/s	W/m²
01/01/90 00:00	0	0	0	-29.764	0	0	0	-4.6099	3.5	0
01/01/90 01:00	0	0	0	-29.764	0	0	0	-4.6903	2.9	0
01/01/90 02:00	0	0	0	-29.764	0	0	0	-5.2298	2.5999	0
01/01/90 03:00	0	0	0	-29.764	0	0	0	-5.5203	2.9	0
01/01/90 04:00	0	0	0	-29.764	0	0	0	-5.8099	2.7999	0
01/01/90 05:00	0	0	0	-29.764	0	0	0	-6.1004	3.1	0
01/01/90 06:00	0	0	0	-29.764	0	0	0	-6.3097	2.7	0
01/01/90 07:00	0	0	0	-29.764	0	0	0	-6.5197	3.5	0
01/01/90 08:00	12.703	8.0465	231.68	87.673	0.2641	14.806	14.797	-6.1696	3.1	0.0094
01/01/90 09:00	245.44	118.33	2798.4	2710.9	0.4226	112.3	63.302	-4.9298	4.5999	48.996
01/01/90 10:00	256.56	149.41	3831.8	3733	0.5567	165.99	127.2	-4.08	4.1	38.796
01/01/90 11:00	287.94	177.34	4592.7	4484.7	0.5959	196.1	156.2	-3.4696	3.9	39.908
01/01/90 12:00	245.12	152.5	4208.2	4105.1	0.6408	184.8	157.5	-3.1903	4.3999	27.303
01/01/90 13:00	267.76	162.32	4249.2	4145.6	0.5924	181.7	145.2	-3.0303	4.9	36.502
01/01/90 14:00	207.67	118.55	3201.4	3109.7	0.5729	137.39	113.2	-3.1099	4.1	24.195
01/01/90 15:00	108.34	53.481	1474.8	1371	0.4842	66.401	57.002	-3.5802	5.7	9.3984

 

Any help would be appreciated,

 

Thanks,

[dtarin]

GlobInc = POA

[Mike99]

Thanks for the answer Dtrain, my system is actually having bifacial modules, how can I get the total irradiance from this raw data?

Does POA actually equals to front POA+ rear POA, or there is an equation to get overall POA for bifacial systems?

 

[Michele Oliosi]

Do you want to have the theoretical plane of array irradiance without shadings, horizon, etc, or the effective irradiance you would measure front side / back side ?
The backside POA irradiance (without applying shadings or horizon) is GlobBak + BackShd (GlobBak has had shadings applied, so some irradiance needs to be reintroduced). GlobInc is the POA irradiance on the front side (without applying shadings, etc).

[Mike99]

I'm trying to do PV system capacity test, and in my real measurement data I do have front and back irradiance measurements, so I am trying to match what I have from actual measurements to PVsyst model, in this case I believe I need GlobBak which has had shading applied.

Just another question on how I can extract the GlobBak data when I extract the weather data from PVsyst, it seems it is not in my export at the moment. I am not able to see it under Data display and verification->Tables->Variables.

Thanks,

[Michele Oliosi]

GlobBak is not technically weather data, since it depends on the system definition.
You should instead run the simulation and create an output file: https://www.pvsyst.com/help/project-design/simulation/create-a-csv-file-of-hourly-daily-values.html

So is BackShd.

Note that if you have defined an horizon profile, you should rather use GlobHrz, instead of GlobInc, for the frontside POA. Indeed, the horizon also affects the solarimeter.