Using cec-modules with sapm

[uvchik]

As I understand it, it is not possible to use the pvlib.pvsystem.sapm function with the cec-modules-library.

Is this right?

If it is right, is it possible to write a hint somewhere in the documentation.

http://pvlib-python.readthedocs.org/en/latest/pvlib.html#pvlib.pvsystem.sapm

[cwhanse]

The CEC library doesn’t contain the parameters that are needed for the SAPM. It only has parameters for the CEC performance model.

NREL might (I’m not sure) have added functionality to translate from CEC model parameters to SAPM parameters. I know PVsyst has done this, but the translation is suspect in my opinion. It works by computing modeled IV curves (using the PVsyst model), picking off Isc, Vmp/Imp and Voc, then fitting the SAPM equations to these modeled points. So you get a SAPM model which emulates the PVsyst model including any biases, rather than measured performance.

Cliff

[wholmgren]

Sure, let's add a hint to the documentation. Feel free to make a PR, otherwise I'll get to it sometime in the next few weeks.

[uvchik]

See PR #123.

[wholmgren]

Closed by #123