change parameter key to pvgis5, etc.

Author: cwhanse

pvlib/pvarray.py

@@ -249,15 +249,16 @@ def _infer_k_huld(cell_type, pdc0, k_version):
     # equation that has factored Pdc0 out of the polynomial:
     #  P = G/1000 * Pdc0 * (1 + k1 log(Geff) + ...) so these parameters are
     # multiplied by pdc0
-    if k_version == '2011':
+    if k_version.lower() == 'pvgis5':
+        # coefficients from PVGIS webpage
         huld_params = {'csi': (-0.017237, -0.040465, -0.004702, 0.000149,
                                0.000170, 0.000005),
                        'cis': (-0.005554, -0.038724, -0.003723, -0.000905,
                                -0.001256, 0.000001),
                        'cdte': (-0.046689, -0.072844, -0.002262, 0.000276,
                                 0.000159, -0.000006)}
-    elif k_version == '2025':
-        # Updated coefficients from EU JRC paper
+    elif k_version.lower() == 'pvgis6':
+        # Coefficients from EU JRC paper
         huld_params = {'csi': (-0.0067560, -0.016444, -0.003015, -0.000045,
                                -0.000043, 0.0),
                        'cis': (-0.011001, -0.029734, -0.002887, 0.000217,
@@ -272,7 +273,7 @@ def _infer_k_huld(cell_type, pdc0, k_version):
 
 
 def huld(effective_irradiance, temp_mod, pdc0, k=None, cell_type=None,
-         k_version='2011'):
+         k_version='pvgis5'):
     r"""
     Power (DC) using the Huld model.
 
@@ -305,10 +306,10 @@ def huld(effective_irradiance, temp_mod, pdc0, k=None, cell_type=None,
         If provided, must be one of ``'cSi'``, ``'CIS'``, or ``'CdTe'``.
         Used to look up default values for ``k`` if ``k`` is not specified.
     k_version : str, optional
-        Either ``'2011'`` (default) or ``'2025'``. Selects values
-        for ``k`` if ``k`` is not specified. If ``'2011'``, values are
-        from PVGIS documentation and are published in [2]_ as "current".
-        If ``'2025'`` values are from [2]_ published as "updated".
+        Either ``'pvgis5'`` (default) or ``'pvgis6'``. Selects values
+        for ``k`` if ``k`` is not specified. If ``'pvgis5'``, values are
+        from PVGIS documentation and are labeled in [2]_ as "current".
+        If ``'pvgis6'`` values are from [2]_ labeled as "updated".
 
     Returns
     -------

tests/test_pvarray.py

@@ -50,6 +50,7 @@ def test_pvefficiency_adr_round_trip():
 
 
 def test_huld():
+    # tests with default k_version='pvgis5'
     pdc0 = 100
     res = pvarray.huld(1000, 25, pdc0, cell_type='cSi')
     assert np.isclose(res, pdc0)
@@ -68,8 +69,9 @@ def test_huld():
     res = pvarray.huld(eff_irr, tm, pdc0, k=(1, 1, 1, 1, 1, 1))
     assert_series_equal(res, expected)
     with pytest.raises(ValueError,
-                       match='Either k or cell_type must be specified'):
-        res = pvarray.huld(1000, 25, 100)
+                       match='Either k or cell_type must be specified'
+                       ):
+        pvarray.huld(1000, 25, 100)
 
 
 def test_huld_params():
@@ -79,26 +81,35 @@ def test_huld_params():
     eff_irr = 800  # W/m^2 (not 1000)
     temp_mod = 35  # deg C (not 25)
     # calculated by C. Hansen using Excel, 2025
-    expected = {'2011': {'csi': 76.405089,
-                         'cis': 77.086016,
-                         'cdte': 78.642762
-                         },
-                '2025': {'csi': 77.649421,
-                         'cis': 77.723110,
-                         'cdte': 77.500399
-                         }
+    expected = {'pvgis5': {'csi': 76.405089,
+                           'cis': 77.086016,
+                           'cdte': 78.642762
+                           },
+                'pvgis6': {'csi': 77.649421,
+                           'cis': 77.723110,
+                           'cdte': 77.500399
+                          }
                 }
-    # Test with 2011 coefficients for all cell types
+    # Test with PVGIS5 coefficients for all cell types
     for yr in expected:
         for cell_type in expected[yr]:
             result = pvarray.huld(eff_irr, temp_mod, pdc0, cell_type=cell_type,
                                   k_version=yr)
             assert np.isclose(result, expected[yr][cell_type])
-    # Check errors for incorrect cell_type and incorrect k_version
+
+
+def test_huld_errors():
+    # Check errors
+    pdc0 = 100
+    # Use non-reference values so coefficients affect the result
+    eff_irr = 800  # W/m^2 (not 1000)
+    temp_mod = 35  # deg C (not 25)
+    # provide both cell_type and k_version
     with pytest.raises(KeyError):
         pvarray.huld(
-            eff_irr, temp_mod, pdc0, cell_type='invalid', k_version='2011'
+            eff_irr, temp_mod, pdc0, cell_type='invalid', k_version='pvgis5'
         )
+    # provide invalid k_version
     with pytest.raises(ValueError, match='Invalid k_version=2021'):
         pvarray.huld(
             eff_irr, temp_mod, pdc0, cell_type='csi', k_version='2021'