work on modelchain

pvlib · cwhanse · Jun 21, 2022 · Jun 9, 2022 · Jun 10, 2022 · Jun 13, 2022
commit e64a9403e0952a5f6f4760d6ed7493b860d17510
diff --git a/pvlib/modelchain.py b/pvlib/modelchain.py
@@ -1500,14 +1500,24 @@ def prepare_inputs(self, weather):
         --------
         ModelChain.complete_irradiance
         """
-        # transfer albedo to weather if needed
-        if 'albedo' in weather.columns:
-            for array in self.system.Arrays:
-                if array.albedo:
-                    raise ValueError('albedo found in both weather and on'
-                                     ' PVsystem. Provide albedo on one or'
-                                     ' on neither, but not on both.')
-                array.albedo = weather['albedo']
+        # transfer albedo from weather to mc.system.arrays if needed
+        if isinstance(weather, pd.DataFrame):
+            if 'albedo' in weather.columns:
+                for array in self.system.arrays:
+                    if hasattr('array', 'albedo'):
+                        raise ValueError('albedo found in both weather and on'
+                                         ' PVsystem.Array Provide albedo on'
+                                         ' one or on neither, but not both.')
+                    array.albedo = weather['albedo']
+        else:  # weather is a list or tuple
+            for w, a in zip(weather, self.system.arrays):
+                if 'albedo' in w.columns:
+                    if hasattr('a', 'albedo'):
+                        raise ValueError('albedo found in both weather and on'
+                                         ' PVsystem.Array Provide albedo on'
+                                         ' one or on neither, but not both.')
+                    a.albedo = weather['albedo']
+
         weather = _to_tuple(weather)
         self._check_multiple_input(weather, strict=False)
         self._verify_df(weather, required=['ghi', 'dni', 'dhi'])

diff --git a/pvlib/tests/test_modelchain.py b/pvlib/tests/test_modelchain.py
@@ -497,6 +497,35 @@ def test_prepare_inputs_multi_weather(
     assert len(mc.results.total_irrad) == num_arrays
 
 
+@pytest.mark.parametrize("input_type", [tuple, list])
+def test_prepare_inputs_transfer_albedo(
+        sapm_dc_snl_ac_system_Array, location, input_type):
+    times = pd.date_range(start='20160101 1200-0700',
+                          end='20160101 1800-0700', freq='6H')
+    mc = ModelChain(sapm_dc_snl_ac_system_Array, location)
+    # albedo on pvsystem but not in weather
+    weather = pd.DataFrame({'ghi': 1, 'dhi': 1, 'dni': 1},
+                           index=times)
+    mc.prepare_inputs(input_type((weather, weather)))
+    num_arrays = sapm_dc_snl_ac_system_Array.num_arrays
+    assert len(mc.results.total_irrad) == num_arrays
+    # albedo on both weather and system
+    weather['albedo'] = 0.5
+    with pytest.raises(ValueError, match='albedo found in both weather'):
+        mc.prepare_inputs(input_type((weather, weather)))
+    # albedo on weather but not system
+    pvsystem = sapm_dc_snl_ac_system_Array
+    for a in pvsystem.arrays:
+        del a.albedo
+    mc = ModelChain(pvsystem, location)
+    mc = mc.prepare_inputs(weather)
+    assert mc.system.arrays[0].albedo==0.5
+    mc = ModelChain(pvsystem, location)
+    mc = mc.prepare_inputs(input_type((weather, weather)))
+    for a in mc.system_arrays:
+        assert a.albedo==0.5

+
 def test_prepare_inputs_no_irradiance(sapm_dc_snl_ac_system, location):
     mc = ModelChain(sapm_dc_snl_ac_system, location)
     weather = pd.DataFrame()