error message, test, docs

Author: cwhanse

docs/sphinx/source/api.rst

@@ -238,6 +238,7 @@ PV temperature models
    temperature.faiman
    temperature.fuentes
    temperature.ross
+   temperature.noct
    pvsystem.PVSystem.sapm_celltemp
    pvsystem.PVSystem.pvsyst_celltemp
    pvsystem.PVSystem.faiman_celltemp

docs/sphinx/source/whatsnew/v0.9.0.rst

@@ -96,6 +96,8 @@ Enhancements
 * :py:meth:`~pvlib.pvsystem.PVSystem.get_ac` is added to calculate AC power
   from DC power. Use parameter ``model`` to specify which inverter model to use.
   (:pull:`1147`, :issue:`998`, :pull:`1150`)
+* Added :py:func:`~pvlib.temperature.noct`, a cell temperature model
+  implemented in SAM (:pull:`1177`)
 
 Bug fixes
 ~~~~~~~~~

pvlib/tests/test_temperature.py

@@ -212,3 +212,45 @@ def test_fuentes_timezone(tz):
 
     assert_series_equal(out, pd.Series([47.85, 50.85, 50.85], index=index,
                                        name='tmod'))
+
+
+def test_noct():
+    poa_global, temp_air, wind_speed, noct, eta_m_ref = (1000., 25., 1., 45.,
+                                                         0.2)
+    expected = 54.41542289
+    result = temperature.noct(poa_global, temp_air, wind_speed, noct,
+                              eta_m_ref)
+    assert np.isclose(result, expected)
+    # test with different types
+    result = temperature.noct(np.array(poa_global), np.array(temp_air),
+                              np.array(wind_speed), np.array(noct),
+                              np.array(eta_m_ref))
+    assert np.isclose(result, expected)
+    dr = pd.date_range(start='2020-01-01 12:00:00', end='2020-01-01 13:00:00',
+                       freq='1H')
+    result = temperature.noct(pd.Series(index=dr, data=poa_global),
+                              pd.Series(index=dr, data=temp_air),
+                              pd.Series(index=dr, data=wind_speed),
+                              pd.Series(index=dr, data=noct),
+                              eta_m_ref)
+    assert_series_equal(result, pd.Series(index=dr, data=expected))
+
+
+def test_noct_options():
+    poa_global, temp_air, wind_speed, noct, eta_m_ref = (1000., 25., 1., 45.,
+                                                         0.2)
+    effective_irradiance = 1100.
+    transmittance_absorbtance = 0.8
+    array_height = 2
+    mount_standoff = 2.0
+    result = temperature.noct(poa_global, temp_air, wind_speed, noct,
+                              eta_m_ref, effective_irradiance,
+                              transmittance_absorbtance, array_height,
+                              mount_standoff)
+    expected = 58.36654459
+    assert np.isclose(result, expected)
+
+
+def test_noct_errors():
+    with pytest.raises(ValueError):
+        temperature.noct(1000., 25., 1., 34., 0.2, array_height=3)