Adds faiman_rad and ross models to get_cell_temperature().

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

@@ -29,6 +29,8 @@ 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`)
+* Include `ross` and `faiman_rad` in the allowed models within 
+  :py:meth:`pvlib.pvsystem.PVSystem.get_cell_temperature` (:issue:`2625`, :pull:`2631`)  
 * Accelerate the internals of :py:func:`~pvlib.solarpostion.ephemeris`. (:pull:`2626`)
 
 Documentation
@@ -84,5 +86,6 @@ Contributors
 * Rohan Saxena (:ghuser:`r0hansaxena`)
 * Marco Fumagalli (:ghuser:`fuma900`)
 * Jean-Baptiste Pasquier (:ghuser:`pasquierjb`)
+* Rodrigo Amaro e Silva (:ghuser:`ramaroesilva`)
 * James Fulton (:ghuser:`dfulu`)
 

pvlib/pvsystem.py

@@ -414,7 +414,7 @@ def get_iam(self, aoi, iam_model='physical'):
 
     @_unwrap_single_value
     def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
-                             effective_irradiance=None):
+                             effective_irradiance=None, longwave_down=None):
         """
         Determine cell temperature using the method specified by ``model``.
 
@@ -431,12 +431,17 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
 
         model : str
             Supported models include ``'sapm'``, ``'pvsyst'``,
-            ``'faiman'``, ``'fuentes'``, and ``'noct_sam'``
+            ``'faiman'``, ``'faiman_rad'``, ``'fuentes'``, ``'noct_sam'``,
+            and ``'ross'``
 
         effective_irradiance : numeric or tuple of numeric, optional
             The irradiance that is converted to photocurrent in W/m^2.
             Only used for some models.
 
+        longwave_down: numeric or tuple of numeric, optional
+            Downwelling long-wave radiation from the sky, measured on a
+            horizontal surface in W/m^2. Only used in ``'faiman_rad'`` model.
+
         Returns
         -------
         numeric or tuple of numeric
@@ -459,14 +464,18 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         # Not used for all models, but Array.get_cell_temperature handles it
         effective_irradiance = self._validate_per_array(effective_irradiance,
                                                         system_wide=True)
+        longwave_down = self._validate_per_array(longwave_down,
+                                                 system_wide=True)
 
         return tuple(
             array.get_cell_temperature(poa_global, temp_air, wind_speed,
-                                       model, effective_irradiance)
-            for array, poa_global, temp_air, wind_speed, effective_irradiance
+                                       model, effective_irradiance,
+                                       longwave_down)
+            for array, poa_global, temp_air, wind_speed, effective_irradiance,
+            longwave_down
             in zip(
                 self.arrays, poa_global, temp_air, wind_speed,
-                effective_irradiance
+                effective_irradiance, longwave_down
             )
         )
 
@@ -1208,7 +1217,7 @@ def get_iam(self, aoi, iam_model='physical'):
             raise ValueError(model + ' is not a valid IAM model')
 
     def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
-                             effective_irradiance=None):
+                             effective_irradiance=None, longwave_down=None):
         """
         Determine cell temperature using the method specified by ``model``.
 
@@ -1222,15 +1231,21 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
 
         wind_speed : numeric
             Wind speed [m/s]
+            When ``model='ross'``, this input is ignored
 
         model : str
             Supported models include ``'sapm'``, ``'pvsyst'``,
-            ``'faiman'``, ``'fuentes'``, and ``'noct_sam'``
+            ``'faiman'``, ``'faiman_rad'``, ``'fuentes'``, ``'noct_sam'``,
+            and ``'ross'``
 
         effective_irradiance : numeric, optional
             The irradiance that is converted to photocurrent in W/m^2.
             Only used for some models.
 
+        longwave_down: numeric, optional
+            Downwelling long-wave radiation from the sky, measured on a
+            horizontal surface in W/m^2. Only used in ``'faiman_rad'`` model.
+
         Returns
         -------
         numeric
@@ -1239,8 +1254,9 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         See Also
         --------
         pvlib.temperature.sapm_cell, pvlib.temperature.pvsyst_cell,
-        pvlib.temperature.faiman, pvlib.temperature.fuentes,
-        pvlib.temperature.noct_sam
+        pvlib.temperature.faiman, pvlib.temperature.faiman_rad,
+        pvlib.temperature.fuentes, pvlib.temperature.noct_sam,
+        pvlib.temperature.ross
 
         Notes
         -----
@@ -1271,6 +1287,13 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
             required = tuple()
             optional = _build_kwargs(['u0', 'u1'],
                                      self.temperature_model_parameters)
+        elif model == 'faiman_rad':
+            func = functools.partial(temperature.faiman_rad,
+                                     ir_down=longwave_down)
+            required = ()
+            optional = _build_kwargs(['u0', 'u1',
+                                      'sky_view', 'emissivity'],
+                                     self.temperature_model_parameters)
         elif model == 'fuentes':
             func = temperature.fuentes
             required = _build_tcell_args(['noct_installed'])
@@ -1287,11 +1310,21 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
             optional = _build_kwargs(['transmittance_absorptance',
                                       'array_height', 'mount_standoff'],
                                      self.temperature_model_parameters)
+        elif model == 'ross':
+            func = temperature.ross
+            required = ()
+            # either noct or k must be defined
+            optional = _build_kwargs(['noct', 'k'],
+                                     self.temperature_model_parameters)
         else:
             raise ValueError(f'{model} is not a valid cell temperature model')
 
-        temperature_cell = func(poa_global, temp_air, wind_speed,
-                                *required, **optional)
+        if model == 'ross':
+            temperature_cell = func(poa_global, temp_air,
+                                    *required, **optional)
+        else:
+            temperature_cell = func(poa_global, temp_air,  wind_speed,
+                                    *required, **optional)
         return temperature_cell
 
     def dc_ohms_from_percent(self):

tests/test_pvsystem.py

@@ -494,6 +494,45 @@ def test_PVSystem_faiman_celltemp(mocker):
     assert_allclose(out, 56.4, atol=1e-1)
 
 
+def test_PVSystem_faiman_rad_celltemp(mocker):
+    longwave_down = 50  # arbitrary value
+    # default values, u0 and u1 being adjusted in same proportion as in
+    # https://www.osti.gov/servlets/purl/1884890/ (not suggested, just example)
+    u0, u1 = 25.0*0.86, 6.84*0.88
+    sky_view = 1.0
+    emissivity = 0.88
+
+    temp_model_params = {'u0': u0, 'u1': u1, 'sky_view': sky_view,
+                         'emissivity': emissivity}
+    system = pvsystem.PVSystem(temperature_model_parameters=temp_model_params)
+    mocker.spy(temperature, 'faiman_rad')
+    temps = 25
+    irrads = 1000
+    winds = 1
+    out = system.get_cell_temperature(irrads, temps, winds,
+                                      model='faiman_rad',
+                                      longwave_down=longwave_down)
+    temperature.faiman_rad.assert_called_once_with(irrads, temps, winds,
+                                                   longwave_down, u0, u1,
+                                                   sky_view, emissivity)
+    assert_allclose(out, 48.6, atol=1e-1)
+
+
+def test_PVSystem_ross_celltemp(mocker):
+    # example value (could use equivalent noct as alternative input)
+    k = 0.0208  # free-standing system
+
+    temp_model_params = {'k': k}
+    system = pvsystem.PVSystem(temperature_model_parameters=temp_model_params)
+    m = mocker.spy(temperature, 'ross')
+    temps = 25
+    irrads = 1000
+    winds = None
+    out = system.get_cell_temperature(irrads, temps, winds, model='ross')
+    m.assert_called_once_with(irrads, temps, k=k)
+    assert_allclose(out, 45.8, atol=1e-1)
+
+
 def test_PVSystem_noct_celltemp(mocker):
     poa_global, temp_air, wind_speed, noct, module_efficiency = (
         1000., 25., 1., 45., 0.2)