Clarify which SAPM parameters are required by module in pvsystem.sapm (#2435)

* Update pvsystem.py

* Update v0.12.1.rst

* Update pvsystem.py

* Update pvsystem.py

* list non-required param instead, units, formatting

* Update pvlib/pvsystem.py

Co-authored-by: Cliff Hansen <cwhanse@sandia.gov>

* update param list (excl. param removed by #2433)

* add blank line for bullet list rendering

* separate C param

---------

Co-authored-by: Cliff Hansen <cwhanse@sandia.gov>

Author: RDaxini

docs/sphinx/source/whatsnew/v0.12.1.rst

@@ -34,8 +34,10 @@ Enhancements
 Documentation
 ~~~~~~~~~~~~~
 * Add a supporting reference to :py:func:`pvlib.atmosphere.get_relative_airmass` (:issue:`2390`, :pull:`2424`)
-* Documented how `np.nan` values are handled by :py:func:`~pvlib.spectrum.average_photon_energy`
+* Document how ``np.nan`` values are handled by :py:func:`~pvlib.spectrum.average_photon_energy`
   (:issue:`2423`, :pull:`2426`)
+* Clarify which SAPM coefficients are required by the ``module`` parameter in
+  :py:func:`~pvlib.pvsystem.sapm` (:issue:`2392`, :pull:`2435`)
 * Update references in :py:func`~pvlib.irradiance.get_extra_radiation`
   (:issue:`2333`, :pull:`2347`)
 

pvlib/pvsystem.py

@@ -2237,12 +2237,25 @@ def sapm(effective_irradiance, temp_cell, module, *, temperature_ref=25,
 
     Notes
     -----
-    The SAPM parameters which are required in ``module`` are
-    listed in the following table.
-
     The Sandia module database contains parameter values for a limited set
     of modules. The CEC module database does not contain these parameters.
-    Both databases can be accessed using :py:func:`retrieve_sam`.
+    Both databases can be accessed using :py:func:`retrieve_sam`. The full list
+    of SAPM parameters is presented in the table below. Those that are required
+    in the ``module`` parameter to run this model are as follows:
+
+    * ``C0``, ``C1``, ``C2``, ``C3``
+    * ``Isco``
+    * ``Impo``
+    * ``Voco``
+    * ``Vmpo``
+    * ``Aisc``
+    * ``Aimp``
+    * ``Bvoco``
+    * ``Mbvoc``
+    * ``Bvmpo``
+    * ``Mbvmp``
+    * ``N``
+    * ``Cells_in_series``
 
     ================   ========================================================
     Key                Description