Temperature loss in SAM

Hi
I would like to extract the temperature loss of the energy production calculation done by SAM.
I am using the CEC Performance Model with Module Database and the NOCT photovoltaic cell temperature model.
From what I read, when the temperature increase, the energy production will slightly decrease with a coefficient of example -0.35% per Celcius degree.
I see the cell temperature can be extracted on the field subarray1_celltemp. Is this indeed the absolute temperature in Celcius or a relative temperature with the reference temperature ?
I assume SAM is calculate the temperature loss with the cell temperature, if that is indeed the case how can we extract the temperature coefficient of power loss %/C or the total annual temperature loss ? I saw some examples at -0.35%/C but I don't see where to extract this value from the specific module in SAM.

Thanks
 

Hi Marc,

The cell temperature value is the temperature of the cell in degrees Celsius. You can find descriptions of SAM's different cell temperature models in the SAM Photovoltaic Reference manual:

Gilman, P.; Dobos, A.; DiOrio, N.; Freeman, J.; Janzou, S.; Ryberg, D. (2018) SAM Photovoltaic Model Technical Reference Update. 93 pp.; NREL/TP-6A20-67399. ( PDF 1.8 MB )

See sam.nrel.gov/photovoltaic/pv-publications.html for other references.

The temperature coefficients used for the cell temperature calculations are inputs to the module model. You can find these on the module page in SAM.

The effect of temperature is included in the "DC module deviation from STC" loss output. That value includes other losses as well -- SAM does not report the effect of temperature as a separate loss.

Best regards,
Paul.