SAM inconstent weather data set

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MySchizoBuddy
Topic Author

21 Jul 2015 02:46 #3548 by MySchizoBuddy

SAM inconstent weather data set was created by MySchizoBuddy

SAM's weather dataset has inconsistent column names and inconsistent column orders. For eg

Australia AUS Adelaide (INTL)
Location City Region Country Latitude Longitude Time Zone Elevation Source
946720 Adelaide AUS Australia -34.930000 138.520000 9.5 4 IWEC

USA AK Ambler (TMY3)
Source Location ID City State Country Latitude Longitude Time Zone Elevation
TMY3 701718 Ambler AK USA 67.100000 -157.850000 -9 88

For Non-USA sites the first column is Location (not location ID as per USA sites). The source column is last compared to USA sites.
For Non-USA sites there is no GHI column and DNI column is called beam and DHI column is called diffuse.

Suggestions
Create one column for Region/State. Or two columns Region and State with appropriate NAs
Pick a column order and stick with it. I prefer location ID to be the First column.
For Non-USA sites there should be a GHI column with NAs. Or it should have calculated GHI from DNI and DHI
All other column names and order should be the same for all sites.

Why do I care? Since in SAM it all works just fine
I'm using the SAM weather data to create an online version of DVIEW.

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Paul Gilman

21 Jul 2015 21:39 #3549 by Paul Gilman

Replied by Paul Gilman on topic SAM inconstent weather data set

For the SAM CSV format, SAM's weather file reader doesn't care what order the columns are in -- it determines the type of data in the column from the column heading. We did this to make it easier for people to create their own weather files, and for SAM to read different kinds of weather files that have different data. For example, some files have a column for snow data and some do not, and this arrangement makes it possible for SAM to read files with and without that data.

Can you write your application to use the column heading to identify data instead of column order?

Best regards,
Paul.

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MySchizoBuddy
Topic Author

28 Jul 2015 17:06 #3550 by MySchizoBuddy

Replied by MySchizoBuddy on topic SAM inconstent weather data set

Thank you Sir,

Yes I'm making the changes so i don't refer by column positions. I'm changing the column names to be consistent. For eg in non-usa sites DNI is called beam. Twet is called Tdew etc

Also I'm assuming Aod column in the non-usa sites means Aerosol optical depth. Also what is Pwp column? perceptible water?

Pwp in the Argentina Buenos_Aires file is all 99.9. Does 99.9 represent NA?

SAM help doesn't even mention Pwp column or what does 99.9 mean.

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Paul Gilman

28 Jul 2015 18:03 #3551 by Paul Gilman

Replied by Paul Gilman on topic SAM inconstent weather data set

SAM does not use the Aod (aerosol optical depth) and Pwp (preciptable water) columns, which is why they are not included in the SAM CSV format description. I am not sure why that data was included in the SAM solar resource files.
Many of the non-U.S. weather files came from the EnergyPlus EPW database, and the precipitable water and aerosol depth data is explained in the EPW format description ( PDF 84 KB ).
Best regards,

Paul.

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