Performance Ratio error

[Paulo Oliveira]

Hello,

I'm doing a grid-connected project on PVsyst 6.70 and this is the first time that I encounter this error. On the advanced simulation and generating the output file I normally use 5 defined variables: 1- Horizontal global irradiation; 2- ambient temperature; 3- effective Global, corr. for IAM and shadings; 4- Energy injected into grid; 5-Performance Ratio. As mentioned before never had any problems using these parameters on the .CSV file. The problem that I have now is some abnormal values on the PR results, 13 PR values with a -1317.8 which seem not to correct.

see bellow:

PVsyst v6.70

File File date Description

Project Desicor_1.PRJ 07/05/18 12h06 Desicor_1

Geographical Site Brunheiro_PVGIS_SAF_1998 to 2011.SIT 07/05/18 12h06 Brunheiro Portugal Europe

Meteo data Brunheiro_PVGIS_SAF_SYN.MET 08/05/18 09h59 Brunheiro Synthetic

Simulation variant Desicor_1.VC3 07/05/18 13h53 320 kWp

Simulation date 08/05/18 10h00

Simulation: Hourly values from 01/01/90 to 31/12/90

date GlobHor T Amb GlobEff E_Grid PR

27/01/1990 07:00 0.1001 9.1302 0 -0.008 -1317.8

16/02/1990 18:00 0.1001 11.6 0 -0.008 -1317.8

14/03/1990 06:00 0.1001 8.5198 0 -0.008 -1317.8

10/04/1990 19:00 0.1001 21.67 0 -0.008 -1317.8

20/04/1990 05:00 0.1001 7.5902 0 -0.008 -1317.8

21/08/1990 05:00 0.1001 17.95 0 -0.008 -1317.8

01/09/1990 19:00 0.1001 24.2 0 -0.008 -1317.8

20/10/1990 06:00 0.1001 15.67 0 -0.008 -1317.8

27/11/1990 17:00 0.1001 13.39 0 -0.008 -1317.8

28/11/1990 17:00 0.1001 11.37 0 -0.008 -1317.8

12/12/1990 07:00 0.1001 7.8202 0 -0.008 -1317.8

22/12/1990 17:00 0.1001 15.68 0 -0.008 -1317.8

23/12/1990 17:00 0.1001 12.74 0 -0.008 -1317.8

Can you please help me solving this?

[André Mermoud]

These are marginal points.

All these data are at beginning or end of the day.

For each one you have a null GlobEff, and a negative yield (night loss).

The error of PVsyst is to issue a value for PR in these conditions. We have to check this.