I'm not sure the difference you are seeing is worth worrying about. Sometimes the CEC (CA Energy. Comm.) Performance model #'s (the common one I believe SAM defaults to) are different than the mfg. data sheet. Two of perhaps many possible sources for this might be: input error at the CEC input level or ongoing updates to the mfg. specs./sheets that don't get to the CEC list, making SAM's #'s somewhat outdated. Sunpower seems to do that more than others, but they sell more stuff too.
To change the parameters in SAM you can change the Module Model Options - Top line on the Module input page, click the change button and follow the bouncing ball and change the inputs.
At the end of the day, SAM does a pretty fair job but, like all other such tools, it's an estimate good to +/- some % and nowhere near as tight as those 16 kWh which, besides due to temp. coeff. diff., may very well also come from other behind the screen 2d level interactions with things like temp. coeff. induced changes in plate temps., etc.
To change the parameters in SAM you can change the Module Model Options - Top line on the Module input page, click the change button and follow the bouncing ball and change the inputs.
At the end of the day, SAM does a pretty fair job but, like all other such tools, it's an estimate good to +/- some % and nowhere near as tight as those 16 kWh which, besides due to temp. coeff. diff., may very well also come from other behind the screen 2d level interactions with things like temp. coeff. induced changes in plate temps., etc.
Comment