Use k and cap_adjustment from Array.module_parameters in PVSystem.pvwatts_dc

docs/sphinx/source/whatsnew/v0.15.1.rst

@@ -20,7 +20,8 @@ Bug fixes
 
 Enhancements
 ~~~~~~~~~~~~
-
+* Use ``k`` and ``cap_adjustment`` from :py:func:`pvlib.pvsystem.Array.module_parameters` in :py:func:`pvlib.pvsystem.PVSystem.pvwatts_dc`
+  (:issue:`2714`, :pull:`2715`)
 
 Documentation
 ~~~~~~~~~~~~~
@@ -70,4 +71,5 @@ Contributors
 * Anton Driesse (:ghuser:`adriesse`)
 * Kevin Anderson (:ghuser:`kandersolar`)
 * Rohan Saxena (:ghuser:`r0hansaxena`)
+* Marco Fumagalli (:ghuser:`fuma900`)
 

pvlib/pvsystem.py

@@ -860,7 +860,7 @@
             pvwatts_dc(effective_irradiance, temp_cell,
                        array.module_parameters['pdc0'],
                        array.module_parameters['gamma_pdc'],
-                       **_build_kwargs(['temp_ref'], array.module_parameters))
+                       **_build_kwargs(['temp_ref', 'k', 'cap_adjustment'], array.module_parameters))
             for array, effective_irradiance, temp_cell
             in zip(self.arrays, effective_irradiance, temp_cell)
         )

tests/test_pvsystem.py

@@ -2260,7 +2260,7 @@
 
 @pytest.fixture
 def pvwatts_system_kwargs():
-    module_parameters = {'pdc0': 100, 'gamma_pdc': -0.003, 'temp_ref': 20}
+    module_parameters = {'pdc0': 100, 'gamma_pdc': -0.003, 'temp_ref': 20, 'k': 0.01, 'cap_adjustment': True}
     inverter_parameters = {'pdc0': 90, 'eta_inv_nom': 0.95, 'eta_inv_ref': 1.0}
     system = pvsystem.PVSystem(module_parameters=module_parameters,
                                inverter_parameters=inverter_parameters)