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I keep getting the error: "Error! Solar altitude is -19 < -6 degrees and Idh = 26 > 10 W/m^2 on day 1 !Ibn is 0. Attempting to continue" for almost all days when I tried to import the TMY file from Meteonorm. Is there a reason behind it?

Also, if we leave the "Mod Wanted" and "Row Wanted" parameters blank, will it tell the average of all the modules?

kevinsa5
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Raj
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1 Answers1

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This happens for the usually really early hours and late hours where there are irradiance values but the sun is underneath the horizon. Also, another particularity is that hourly data can be left or right labeled (i.e., data timestamped at 8 AM might be the average of 8 to 9 AM, or from 7 to 8 AM.), and the sun position can then be alculated for 8:30 AM, 8, or 7:30 AM. Previously our default was 7:30 AM, but if the sun had not risen yet that cuases issues. Besides the fact that you can now select if the data is right labeled or left labeled, the sunrise and sunset hours get checked and modified, so that for example if the sun rose at 7:40 AM and the data at that 8 AM timestam is from 7 to 8 AM, the sun position will be calculated in the midpoint between sunrise and the hour so 7:50 AM....

In general, that error doesn't forbid you from continuing, and the irradiance contribution from those hours is minimal.

  1. Regarding the second question --- no, if module wanted and row wanted are not specified, the center of the array is chosen and sampled. It is not the average of all modules.
shirubana
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