Issue with the DNI data and weather file before the simulation.

Hi,
I am working on the SAM in CSP with parabolic trough (physical model). I put the values of the all the parameters for the location 28.428, 77.159. (1MWe National solar thermal power plant Gurgaon, Haryana, India) I attached the SAM file. And also attached the excel file for the reference 2020 year data. I have the data of the DNI that I want to see in the results but when I put this data in the excel and then upload on the SAM and simulate so I am not able to get the exact data of the DNI in the results. It saw like something difference between what I put and what I got.
1.My problem here is about how can I get the same data that I had put before the simulation and also the terms like clearsky DNI, DHI, GHI affects it or not. If these terms affects it then how can I calculate these values according to my DNI data and will put in the SAM ?
2. And also I am able to getting the data from 30 minutes, 5  minutes, So if I am change for I minutes and 1 seconds in the excel, is it works or not ?
3. And this all data(DNI, clearsky DNI, alpha, cosine, ozone etc.) are for the year 2020. Where can I find out these data for this location in present(2025 or 2024) ?

Hi Abhishek,

1. SAM's Physical Trough model does not report data from the weather file in the results. You can display data from the weather file by clicking View data on the Location and Resource page. The simulation output variable "Field collector DNI-cosine product (W/2)" is the DNI available to the collector in the collector plane. You can calculate the weather DNI value from that variable and the "Field collector cosine efficiency" output variable:

DNI from Weather File (W/m2) = Field collector DNI-cosine product (W/m2) / Field Collector Cosine Efficiency

2. Yes, the Physical Trough model work with 5-minute and 30-minute weather data. The weather file format must meet the requirements described in the "SAM CSV Format for Solar" topic in Help:  samrepo.nrelcloud.org/help/weather_format_sam_csv_solar.html

3. The NREL NSRDB does not have data for 2024 or 2025 for locations in India. The Weather Data page of the SAM website lists additional sources of weather data:  sam.nrel.gov/weather-data.html .

Best regards,
Paul.