1759 resolve attrib error model chain (#1947)

* Remove or clause from if clause in infer_temperature_model in ModelChain

* Updated what's new

* Remove comment about removing or statement in infer_temperature_model in modelchain.py

* Added test to verify that error indicating inability to infer temperature model is raised when not providing temperature model to arrays

* Update docs/sphinx/source/whatsnew/v0.10.4.rst

Co-authored-by: Kevin Anderson <[email protected]>

* Update pvlib/tests/test_modelchain.py

---------

Co-authored-by: Kevin Anderson <[email protected]>

Author: matsuobasho

docs/sphinx/source/whatsnew/v0.10.4.rst

@@ -11,7 +11,8 @@ Enhancements
 
 Bug fixes
 ~~~~~~~~~
-
+* :py:class:`~pvlib.modelchain.ModelChain` now raises a more useful error when
+  ``temperature_model_parameters`` are specified on the passed ``system`` instead of on its ``arrays``. (:issue:`1759`).
 
 Testing
 ~~~~~~~
@@ -27,4 +28,4 @@ Requirements
 
 Contributors
 ~~~~~~~~~~~~
-
+* :ghuser:`matsuobasho`

pvlib/modelchain.py

@@ -1117,10 +1117,7 @@ def infer_temperature_model(self):
         temperature_model_parameters = tuple(
             array.temperature_model_parameters for array in self.system.arrays)
         params = _common_keys(temperature_model_parameters)
-        # remove or statement in v0.9
-        if {'a', 'b', 'deltaT'} <= params or (
-                not params and self.system.racking_model is None
-                and self.system.module_type is None):
+        if {'a', 'b', 'deltaT'} <= params:
             return self.sapm_temp
         elif {'u_c', 'u_v'} <= params:
             return self.pvsyst_temp

pvlib/tests/test_modelchain.py

@@ -1305,6 +1305,22 @@ def test_temperature_model_inconsistent(location, sapm_dc_snl_ac_system):
                    spectral_model='no_loss', temperature_model='pvsyst')
 
 
+def test_temperature_model_not_specified():
+    # GH 1759 -- ensure correct error is raised when temperature model params
+    # are specified on the PVSystem instead of the Arrays
+    location = Location(latitude=32.2, longitude=-110.9)
+    arrays = [pvsystem.Array(pvsystem.FixedMount(),
+                             module_parameters={'pdc0': 1, 'gamma_pdc': 0})]
+    system = pvsystem.PVSystem(arrays,
+                               temperature_model_parameters={'u0': 1, 'u1': 1},
+                               inverter_parameters={'pdc0': 1})
+    with pytest.raises(ValueError,
+                       match='could not infer temperature model '
+                             'from system.temperature_model_parameters'):
+        _ = ModelChain(system, location,
+                       aoi_model='no_loss', spectral_model='no_loss')
+
+
 def test_dc_model_user_func(pvwatts_dc_pvwatts_ac_system, location, weather,
                             mocker):
     m = mocker.spy(sys.modules[__name__], 'poadc')