From 6b69027886bf14d5c0288cbaf0a1a317bd9c2a53 Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Wed, 14 Apr 2021 20:30:48 -0600
Subject: [PATCH 01/21] add Array.get_cell_temperature and
 PVSystem.get_cell_temperature, deprecate old PVSystem tcell methods, update
 ModelChain._set_celltemp

---
 pvlib/modelchain.py |  16 +--
 pvlib/pvsystem.py   | 264 +++++++++++++++++++++++++-------------------
 2 files changed, 161 insertions(+), 119 deletions(-)

diff --git a/pvlib/modelchain.py b/pvlib/modelchain.py
index 331d34d835..08a1ac7b91 100644
--- a/pvlib/modelchain.py
+++ b/pvlib/modelchain.py
@@ -1009,26 +1009,26 @@ def _set_celltemp(self, model):
         temp_air = _tuple_from_dfs(self.results.weather, 'temp_air')
         wind_speed = _tuple_from_dfs(self.results.weather, 'wind_speed')
         kwargs = {}
-        if model == self.system.noct_sam_celltemp:
+        if model == 'noct_sam':
             kwargs['effective_irradiance'] = self.results.effective_irradiance
-        self.results.cell_temperature = model(poa, temp_air, wind_speed,
-                                              **kwargs)
+        self.results.cell_temperature = self.system.get_cell_temperature(
+                poa, temp_air, wind_speed, model=model, **kwargs)
         return self
 
     def sapm_temp(self):
-        return self._set_celltemp(self.system.sapm_celltemp)
+        return self._set_celltemp('sapm')
 
     def pvsyst_temp(self):
-        return self._set_celltemp(self.system.pvsyst_celltemp)
+        return self._set_celltemp('pvsyst')
 
     def faiman_temp(self):
-        return self._set_celltemp(self.system.faiman_celltemp)
+        return self._set_celltemp('faiman')
 
     def fuentes_temp(self):
-        return self._set_celltemp(self.system.fuentes_celltemp)
+        return self._set_celltemp('fuentes')
 
     def noct_sam_temp(self):
-        return self._set_celltemp(self.system.noct_sam_celltemp)
+        return self._set_celltemp('noct_sam')
 
     @property
     def dc_ohmic_model(self):
diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index f6901617c3..31dcc0aa56 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -378,6 +378,61 @@ def get_iam(self, aoi, iam_model='physical'):
         return tuple(array.get_iam(aoi, iam_model)
                      for array, aoi in zip(self.arrays, aoi))
 
+    @_unwrap_single_value
+    def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
+                             **kwargs):
+        """
+        Determine cell temperature using the method specified by ``model``.
+
+        Parameters
+        ----------
+        poa_global : numeric or tuple of numeric
+            Total incident irradiance in W/m^2.
+
+        temp_air : numeric or tuple of numeric
+            Ambient dry bulb temperature in degrees C.
+
+        wind_speed : numeric or tuple of numeric
+            Wind speed in m/s.
+
+        Returns
+        -------
+        numeric or tuple of numeric
+            values in degrees C.
+
+        Notes
+        -----
+        The `temp_air` and `wind_speed` parameters may be passed as tuples
+        to provide different values for each Array in the system. If not
+        passed as a tuple then the same value is used for input to each Array.
+        If passed as a tuple the length must be the same as the number of
+        Arrays.
+        """
+        poa_global = self._validate_per_array(poa_global)
+        temp_air = self._validate_per_array(temp_air, system_wide=True)
+        wind_speed = self._validate_per_array(wind_speed, system_wide=True)
+
+        # additional model-specific (and array-specific) inputs
+        extra_inputs = [{}] * self.num_arrays
+
+        if 'effective_irradiance' in kwargs:
+            effective_irradiance = kwargs.pop('effective_irradiance')
+            if effective_irradiance is None:
+                effective_irradiance = tuple([None] * self.num_arrays)
+            else:
+                effective_irradiance = self._validate_per_array(
+                    effective_irradiance)
+            for inputs, value in zip(extra_inputs, effective_irradiance):
+                inputs['effective_irradiance'] = value
+
+        return tuple(
+            array.get_cell_temperature(poa_global, temp_air, wind_speed,
+                                       model, **extra, **kwargs)
+            for array, poa_global, temp_air, wind_speed, extra in zip(
+                self.arrays, poa_global, temp_air, wind_speed, extra_inputs
+            )
+        )
+
     @_unwrap_single_value
     def calcparams_desoto(self, effective_irradiance, temp_cell, **kwargs):
         """
@@ -531,7 +586,8 @@ def sapm(self, effective_irradiance, temp_cell, **kwargs):
             in zip(self.arrays, effective_irradiance, temp_cell)
         )
 
-    @_unwrap_single_value
+    @deprecated('0.9', alternative='PVSystem.get_cell_temperature',
+                removal='0.10.0')
     def sapm_celltemp(self, poa_global, temp_air, wind_speed):
         """Uses :py:func:`temperature.sapm_cell` to calculate cell
         temperatures.
@@ -560,20 +616,8 @@ def sapm_celltemp(self, poa_global, temp_air, wind_speed):
         If passed as a tuple the length must be the same as the number of
         Arrays.
         """
-        poa_global = self._validate_per_array(poa_global)
-        temp_air = self._validate_per_array(temp_air, system_wide=True)
-        wind_speed = self._validate_per_array(wind_speed, system_wide=True)
-
-        build_kwargs = functools.partial(_build_kwargs, ['a', 'b', 'deltaT'])
-        return tuple(
-            temperature.sapm_cell(
-                poa_global, temp_air, wind_speed,
-                **build_kwargs(array.temperature_model_parameters)
-            )
-            for array, poa_global, temp_air, wind_speed in zip(
-                self.arrays, poa_global, temp_air, wind_speed
-            )
-        )
+        return self.get_cell_temperature(poa_global, temp_air, wind_speed,
+                                         model='sapm')
 
     @_unwrap_single_value
     def sapm_spectral_loss(self, airmass_absolute):
@@ -635,7 +679,8 @@ def sapm_effective_irradiance(self, poa_direct, poa_diffuse,
             in zip(self.arrays, poa_direct, poa_diffuse, aoi)
         )
 
-    @_unwrap_single_value
+    @deprecated('0.9', alternative='PVSystem.get_cell_temperature',
+                removal='0.10.0')
     def pvsyst_celltemp(self, poa_global, temp_air, wind_speed=1.0):
         """Uses :py:func:`temperature.pvsyst_cell` to calculate cell
         temperature.
@@ -666,24 +711,11 @@ def pvsyst_celltemp(self, poa_global, temp_air, wind_speed=1.0):
         If passed as a tuple the length must be the same as the number of
         Arrays.
         """
-        poa_global = self._validate_per_array(poa_global)
-        temp_air = self._validate_per_array(temp_air, system_wide=True)
-        wind_speed = self._validate_per_array(wind_speed, system_wide=True)
+        return self.get_cell_temperature(poa_global, temp_air, wind_speed,
+                                         model='pvsyst')
 
-        def build_celltemp_kwargs(array):
-            return {**_build_kwargs(['eta_m', 'alpha_absorption'],
-                                    array.module_parameters),
-                    **_build_kwargs(['u_c', 'u_v'],
-                                    array.temperature_model_parameters)}
-        return tuple(
-            temperature.pvsyst_cell(poa_global, temp_air, wind_speed,
-                                    **build_celltemp_kwargs(array))
-            for array, poa_global, temp_air, wind_speed in zip(
-                self.arrays, poa_global, temp_air, wind_speed
-            )
-        )
-
-    @_unwrap_single_value
+    @deprecated('0.9', alternative='PVSystem.get_cell_temperature',
+                removal='0.10.0')
     def faiman_celltemp(self, poa_global, temp_air, wind_speed=1.0):
         """
         Use :py:func:`temperature.faiman` to calculate cell temperature.
@@ -714,20 +746,11 @@ def faiman_celltemp(self, poa_global, temp_air, wind_speed=1.0):
         If passed as a tuple the length must be the same as the number of
         Arrays.
         """
-        poa_global = self._validate_per_array(poa_global)
-        temp_air = self._validate_per_array(temp_air, system_wide=True)
-        wind_speed = self._validate_per_array(wind_speed, system_wide=True)
-        return tuple(
-            temperature.faiman(
-                poa_global, temp_air, wind_speed,
-                **_build_kwargs(
-                    ['u0', 'u1'], array.temperature_model_parameters))
-            for array, poa_global, temp_air, wind_speed in zip(
-                self.arrays, poa_global, temp_air, wind_speed
-            )
-        )
+        return self.get_cell_temperature(poa_global, temp_air, wind_speed,
+                                         model='faiman')
 
-    @_unwrap_single_value
+    @deprecated('0.9', alternative='PVSystem.get_cell_temperature',
+                removal='0.10.0')
     def fuentes_celltemp(self, poa_global, temp_air, wind_speed):
         """
         Use :py:func:`temperature.fuentes` to calculate cell temperature.
@@ -763,30 +786,11 @@ def fuentes_celltemp(self, poa_global, temp_air, wind_speed):
         If passed as a tuple the length must be the same as the number of
         Arrays.
         """
-        # default to using the Array attribute, but allow user to
-        # override with a custom surface_tilt value
-        poa_global = self._validate_per_array(poa_global)
-        temp_air = self._validate_per_array(temp_air, system_wide=True)
-        wind_speed = self._validate_per_array(wind_speed, system_wide=True)
-
-        def _build_kwargs_fuentes(array):
-            kwargs = {'surface_tilt': array.surface_tilt}
-            temp_model_kwargs = _build_kwargs([
-                'noct_installed', 'module_height', 'wind_height', 'emissivity',
-                'absorption', 'surface_tilt', 'module_width', 'module_length'],
-                array.temperature_model_parameters)
-            kwargs.update(temp_model_kwargs)
-            return kwargs
-        return tuple(
-            temperature.fuentes(
-                poa_global, temp_air, wind_speed,
-                **_build_kwargs_fuentes(array))
-            for array, poa_global, temp_air, wind_speed in zip(
-                self.arrays, poa_global, temp_air, wind_speed
-            )
-        )
+        return self.get_cell_temperature(poa_global, temp_air, wind_speed,
+                                         model='fuentes')
 
-    @_unwrap_single_value
+    @deprecated('0.9', alternative='PVSystem.get_cell_temperature',
+                removal='0.10.0')
     def noct_sam_celltemp(self, poa_global, temp_air, wind_speed,
                           effective_irradiance=None):
         """
@@ -820,47 +824,9 @@ def noct_sam_celltemp(self, poa_global, temp_air, wind_speed,
         If passed as a tuple the length must be the same as the number of
         Arrays.
         """
-        # default to using the Array attribute, but allow user to
-        # override with a custom surface_tilt value
-        poa_global = self._validate_per_array(poa_global)
-        temp_air = self._validate_per_array(temp_air, system_wide=True)
-        wind_speed = self._validate_per_array(wind_speed, system_wide=True)
-
-        # need effective_irradiance to be an iterable
-        if effective_irradiance is None:
-            effective_irradiance = tuple([None] * self.num_arrays)
-        else:
-            effective_irradiance = self._validate_per_array(
-                effective_irradiance)
-
-        def _build_kwargs_noct_sam(array):
-            temp_model_kwargs = _build_kwargs([
-                'transmittance_absorptance',
-                'array_height', 'mount_standoff'],
-                array.temperature_model_parameters)
-            try:
-                # noct_sam required args
-                # bundled with kwargs for simplicity
-                temp_model_kwargs['noct'] = \
-                    array.temperature_model_parameters['noct']
-                temp_model_kwargs['eta_m_ref'] = \
-                    array.temperature_model_parameters['eta_m_ref']
-            except KeyError:
-                msg = ('Parameters noct and eta_m_ref are required.'
-                       ' Found {} in temperature_model_parameters.'
-                       .format(array.temperature_model_parameters))
-                raise KeyError(msg)
-            return temp_model_kwargs
-        return tuple(
-            temperature.noct_sam(
-                poa_global, temp_air, wind_speed,
-                effective_irradiance=eff_irrad,
-                **_build_kwargs_noct_sam(array))
-            for array, poa_global, temp_air, wind_speed, eff_irrad in zip(
-                self.arrays, poa_global, temp_air, wind_speed,
-                effective_irradiance
-            )
-        )
+        return self.get_cell_temperature(
+            poa_global, temp_air, wind_speed, model='noct_sam',
+            effective_irradiance=effective_irradiance)
 
     @_unwrap_single_value
     def first_solar_spectral_loss(self, pw, airmass_absolute):
@@ -1314,7 +1280,6 @@ def _infer_temperature_model_params(self):
             return {}
 
     def _infer_cell_type(self):
-
         """
         Examines module_parameters and maps the Technology key for the CEC
         database and the Material key for the Sandia database to a common
@@ -1473,6 +1438,83 @@ def get_iam(self, aoi, iam_model='physical'):
         else:
             raise ValueError(model + ' is not a valid IAM model')
 
+    def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
+                             **kwargs):
+        """
+        Determine cell temperature using the method specified by ``model``.
+
+        Parameters
+        ----------
+        poa_global : numeric
+            Total incident irradiance [W/m^2]
+
+        temp_air : numeric
+            Ambient dry bulb temperature [C]
+
+        wind_speed : numeric
+            Wind speed [m/s]
+
+        model : str
+            Supported models include ``'sapm'``, ``'pvsyst'``,
+            ``'faiman'``, ``'fuentes'``, and ``'noct_sam'``
+
+        **kwargs
+            Extra arguments passed to the model function.
+
+        Returns
+        -------
+        numeric
+            values in degrees C.
+
+        Notes
+        -----
+        Some temperature models have requirements for the input types;
+        see the documentation of the underlying model function for details.
+        """
+        if model == 'sapm':
+            func = temperature.sapm_cell
+            params = _build_kwargs(['a', 'b', 'deltaT'],
+                                   self.temperature_model_parameters)
+        elif model == 'pvsyst':
+            func = temperature.pvsyst_cell
+            params = {
+                **_build_kwargs(['eta_m', 'alpha_absorption'],
+                                self.module_parameters),
+                **_build_kwargs(['u_c', 'u_v'],
+                                self.temperature_model_parameters)
+            }
+        elif model == 'faiman':
+            func = temperature.faiman
+            params = _build_kwargs(['u0', 'u1'],
+                                   self.temperature_model_parameters)
+        elif model == 'fuentes':
+            func = temperature.fuentes
+            # default to using the Array attribute, but allow user to override
+            # with a custom surface_tilt value in temperature_model_parameters
+            params = _build_kwargs([
+                'noct_installed', 'module_height', 'wind_height', 'emissivity',
+                'absorption', 'surface_tilt', 'module_width', 'module_length'],
+                self.temperature_model_parameters)
+            if 'surface_tilt' not in params:
+                params['surface_tilt'] = self.surface_tilt
+        elif model == 'noct_sam':
+            func = temperature.noct_sam
+            params = _build_kwargs(['transmittance_absorptance', 'eta_m_ref',
+                                    'noct', 'array_height', 'mount_standoff'],
+                                   self.temperature_model_parameters)
+            if not {'noct', 'eta_m_ref'}.issubset(params):
+                msg = ('Parameters noct and eta_m_ref are required.'
+                       ' Found {} in temperature_model_parameters.'
+                       .format(self.temperature_model_parameters))
+                raise KeyError(msg)
+        else:
+            raise ValueError(f'{model} is not a valid cell temperature model')
+
+        # allow kwargs to override
+        params.update(kwargs)
+        temperature_cell = func(poa_global, temp_air, wind_speed, **params)
+        return temperature_cell
+
     def dc_ohms_from_percent(self):
         """
         Calculates the equivalent resistance of the wires using

From 6b7dcff7223faf49c0c4378b3ac47bcb79f7ed7e Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Wed, 14 Apr 2021 20:30:56 -0600
Subject: [PATCH 02/21] fix tests

---
 pvlib/tests/test_modelchain.py |  17 +--
 pvlib/tests/test_pvsystem.py   | 188 ++++++++++++++++-----------------
 2 files changed, 103 insertions(+), 102 deletions(-)

diff --git a/pvlib/tests/test_modelchain.py b/pvlib/tests/test_modelchain.py
index 3652fc097a..8ab22d28ba 100644
--- a/pvlib/tests/test_modelchain.py
+++ b/pvlib/tests/test_modelchain.py
@@ -642,13 +642,14 @@ def test_run_model_with_weather_sapm_temp(sapm_dc_snl_ac_system, location,
     weather['temp_air'] = 10
     mc = ModelChain(sapm_dc_snl_ac_system, location)
     mc.temperature_model = 'sapm'
-    m_sapm = mocker.spy(sapm_dc_snl_ac_system, 'sapm_celltemp')
+    m_sapm = mocker.spy(sapm_dc_snl_ac_system, 'get_cell_temperature')
     mc.run_model(weather)
     assert m_sapm.call_count == 1
     # assert_called_once_with cannot be used with series, so need to use
     # assert_series_equal on call_args
     assert_series_equal(m_sapm.call_args[0][1], weather['temp_air'])  # temp
     assert_series_equal(m_sapm.call_args[0][2], weather['wind_speed'])  # wind
+    assert m_sapm.call_args[1]['model'] == 'sapm'
     assert not mc.results.ac.empty
 
 
@@ -662,11 +663,12 @@ def test_run_model_with_weather_pvsyst_temp(sapm_dc_snl_ac_system, location,
         temperature._temperature_model_params('pvsyst', 'freestanding')
     mc = ModelChain(sapm_dc_snl_ac_system, location)
     mc.temperature_model = 'pvsyst'
-    m_pvsyst = mocker.spy(sapm_dc_snl_ac_system, 'pvsyst_celltemp')
+    m_pvsyst = mocker.spy(sapm_dc_snl_ac_system, 'get_cell_temperature')
     mc.run_model(weather)
     assert m_pvsyst.call_count == 1
     assert_series_equal(m_pvsyst.call_args[0][1], weather['temp_air'])
     assert_series_equal(m_pvsyst.call_args[0][2], weather['wind_speed'])
+    assert m_pvsyst.call_args[1]['model'] == 'pvsyst'
     assert not mc.results.ac.empty
 
 
@@ -680,11 +682,12 @@ def test_run_model_with_weather_faiman_temp(sapm_dc_snl_ac_system, location,
     }
     mc = ModelChain(sapm_dc_snl_ac_system, location)
     mc.temperature_model = 'faiman'
-    m_faiman = mocker.spy(sapm_dc_snl_ac_system, 'faiman_celltemp')
+    m_faiman = mocker.spy(sapm_dc_snl_ac_system, 'get_cell_temperature')
     mc.run_model(weather)
     assert m_faiman.call_count == 1
     assert_series_equal(m_faiman.call_args[0][1], weather['temp_air'])
     assert_series_equal(m_faiman.call_args[0][2], weather['wind_speed'])
+    assert m_faiman.call_args[1]['model'] == 'faiman'
     assert not mc.results.ac.empty
 
 
@@ -697,11 +700,12 @@ def test_run_model_with_weather_fuentes_temp(sapm_dc_snl_ac_system, location,
     }
     mc = ModelChain(sapm_dc_snl_ac_system, location)
     mc.temperature_model = 'fuentes'
-    m_fuentes = mocker.spy(sapm_dc_snl_ac_system, 'fuentes_celltemp')
+    m_fuentes = mocker.spy(sapm_dc_snl_ac_system, 'get_cell_temperature')
     mc.run_model(weather)
     assert m_fuentes.call_count == 1
     assert_series_equal(m_fuentes.call_args[0][1], weather['temp_air'])
     assert_series_equal(m_fuentes.call_args[0][2], weather['wind_speed'])
+    assert m_fuentes.call_args[1]['model'] == 'fuentes'
     assert not mc.results.ac.empty
 
 
@@ -714,14 +718,15 @@ def test_run_model_with_weather_noct_sam_temp(sapm_dc_snl_ac_system, location,
     }
     mc = ModelChain(sapm_dc_snl_ac_system, location)
     mc.temperature_model = 'noct_sam'
-    m_noct_sam = mocker.spy(sapm_dc_snl_ac_system, 'noct_sam_celltemp')
+    m_noct_sam = mocker.spy(sapm_dc_snl_ac_system, 'get_cell_temperature')
     mc.run_model(weather)
     assert m_noct_sam.call_count == 1
     assert_series_equal(m_noct_sam.call_args[0][1], weather['temp_air'])
     assert_series_equal(m_noct_sam.call_args[0][2], weather['wind_speed'])
     # check that effective_irradiance was used
     assert m_noct_sam.call_args[1] == {
-        'effective_irradiance': mc.results.effective_irradiance}
+        'effective_irradiance': mc.results.effective_irradiance,
+        'model': 'noct_sam'}
 
 
 def test_run_model_tracker(sapm_dc_snl_ac_system, location, weather, mocker):
diff --git a/pvlib/tests/test_pvsystem.py b/pvlib/tests/test_pvsystem.py
index 2d20660b98..a7b37ad9d6 100644
--- a/pvlib/tests/test_pvsystem.py
+++ b/pvlib/tests/test_pvsystem.py
@@ -429,7 +429,7 @@ def test_PVSystem_sapm_celltemp(mocker):
     temps = 25
     irrads = 1000
     winds = 1
-    out = system.sapm_celltemp(irrads, temps, winds)
+    out = system.get_cell_temperature(irrads, temps, winds, model='sapm')
     temperature.sapm_cell.assert_called_once_with(irrads, temps, winds, a, b,
                                                   deltaT)
     assert_allclose(out, 57, atol=1)
@@ -443,7 +443,7 @@ def test_PVSystem_sapm_celltemp_kwargs(mocker):
     temps = 25
     irrads = 1000
     winds = 1
-    out = system.sapm_celltemp(irrads, temps, winds)
+    out = system.get_cell_temperature(irrads, temps, winds, model='sapm')
     temperature.sapm_cell.assert_called_once_with(irrads, temps, winds,
                                                   temp_model_params['a'],
                                                   temp_model_params['b'],
@@ -460,8 +460,8 @@ def test_PVSystem_multi_array_sapm_celltemp_different_arrays():
         arrays=[pvsystem.Array(temperature_model_parameters=temp_model_one),
                 pvsystem.Array(temperature_model_parameters=temp_model_two)]
     )
-    temp_one, temp_two = system.sapm_celltemp(
-        (1000, 1000), 25, 1
+    temp_one, temp_two = system.get_cell_temperature(
+        (1000, 1000), 25, 1, model='sapm'
     )
     assert temp_one != temp_two
 
@@ -479,7 +479,8 @@ def test_PVSystem_pvsyst_celltemp(mocker):
     irrad = 800
     temp = 45
     wind = 0.5
-    out = system.pvsyst_celltemp(irrad, temp, wind_speed=wind)
+    out = system.get_cell_temperature(irrad, temp, wind_speed=wind,
+                                      model='pvsyst')
     temperature.pvsyst_cell.assert_called_once_with(
         irrad, temp, wind, temp_model_params['u_c'], temp_model_params['u_v'],
         eta_m, alpha_absorption)
@@ -494,7 +495,7 @@ def test_PVSystem_faiman_celltemp(mocker):
     temps = 25
     irrads = 1000
     winds = 1
-    out = system.faiman_celltemp(irrads, temps, winds)
+    out = system.get_cell_temperature(irrads, temps, winds, model='faiman')
     temperature.faiman.assert_called_once_with(irrads, temps, winds, u0, u1)
     assert_allclose(out, 56.4, atol=1)
 
@@ -506,20 +507,21 @@ def test_PVSystem_noct_celltemp(mocker):
     temp_model_params = {'noct': noct, 'eta_m_ref': eta_m_ref}
     system = pvsystem.PVSystem(temperature_model_parameters=temp_model_params)
     mocker.spy(temperature, 'noct_sam')
-    out = system.noct_sam_celltemp(poa_global, temp_air, wind_speed)
+    out = system.get_cell_temperature(poa_global, temp_air, wind_speed,
+                                      model='noct_sam')
     temperature.noct_sam.assert_called_once_with(
-        poa_global, temp_air, wind_speed, effective_irradiance=None, noct=noct,
-        eta_m_ref=eta_m_ref)
+        poa_global, temp_air, wind_speed, noct=noct, eta_m_ref=eta_m_ref)
     assert_allclose(out, expected)
-    # dufferent types
-    out = system.noct_sam_celltemp(np.array(poa_global), np.array(temp_air),
-                                   np.array(wind_speed))
+    # different types
+    out = system.get_cell_temperature(np.array(poa_global), np.array(temp_air),
+                                      np.array(wind_speed), model='noct_sam')
     assert_allclose(out, expected)
     dr = pd.date_range(start='2020-01-01 12:00:00', end='2020-01-01 13:00:00',
                        freq='1H')
-    out = system.noct_sam_celltemp(pd.Series(index=dr, data=poa_global),
-                                   pd.Series(index=dr, data=temp_air),
-                                   pd.Series(index=dr, data=wind_speed))
+    out = system.get_cell_temperature(pd.Series(index=dr, data=poa_global),
+                                      pd.Series(index=dr, data=temp_air),
+                                      pd.Series(index=dr, data=wind_speed),
+                                      model='noct_sam')
     assert_series_equal(out, pd.Series(index=dr, data=expected))
     # now use optional arguments
     temp_model_params.update({'transmittance_absorptance': 0.8,
@@ -527,8 +529,9 @@ def test_PVSystem_noct_celltemp(mocker):
                               'mount_standoff': 2.0})
     expected = 60.477703576
     system = pvsystem.PVSystem(temperature_model_parameters=temp_model_params)
-    out = system.noct_sam_celltemp(poa_global, temp_air, wind_speed,
-                                   effective_irradiance=1100.)
+    out = system.get_cell_temperature(poa_global, temp_air, wind_speed,
+                                      effective_irradiance=1100.,
+                                      model='noct_sam')
     assert_allclose(out, expected)
 
 
@@ -537,147 +540,120 @@ def test_PVSystem_noct_celltemp_error():
     temp_model_params = {'eta_m_ref': eta_m_ref}
     system = pvsystem.PVSystem(temperature_model_parameters=temp_model_params)
     with pytest.raises(KeyError):
-        system.noct_sam_celltemp(poa_global, temp_air, wind_speed)
+        system.get_cell_temperature(poa_global, temp_air, wind_speed,
+                                    model='noct_sam')
 
 
-@pytest.mark.parametrize("celltemp",
-                         [pvsystem.PVSystem.faiman_celltemp,
-                          pvsystem.PVSystem.pvsyst_celltemp,
-                          pvsystem.PVSystem.sapm_celltemp,
-                          pvsystem.PVSystem.fuentes_celltemp,
-                          pvsystem.PVSystem.noct_sam_celltemp])
-def test_PVSystem_multi_array_celltemp_functions(celltemp, two_array_system):
+@pytest.mark.parametrize("model",
+                         ['faiman', 'pvsyst', 'sapm', 'fuentes', 'noct_sam'])
+def test_PVSystem_multi_array_celltemp_functions(model, two_array_system):
     times = pd.date_range(start='2020-08-25 11:00', freq='H', periods=3)
     irrad_one = pd.Series(1000, index=times)
     irrad_two = pd.Series(500, index=times)
     temp_air = pd.Series(25, index=times)
     wind_speed = pd.Series(1, index=times)
-    temp_one, temp_two = celltemp(
-        two_array_system, (irrad_one, irrad_two), temp_air, wind_speed)
+    temp_one, temp_two = two_array_system.get_cell_temperature(
+            (irrad_one, irrad_two), temp_air, wind_speed, model=model)
     assert (temp_one != temp_two).all()
 
 
-@pytest.mark.parametrize("celltemp",
-                         [pvsystem.PVSystem.faiman_celltemp,
-                          pvsystem.PVSystem.pvsyst_celltemp,
-                          pvsystem.PVSystem.sapm_celltemp,
-                          pvsystem.PVSystem.fuentes_celltemp,
-                          pvsystem.PVSystem.noct_sam_celltemp])
-def test_PVSystem_multi_array_celltemp_multi_temp(celltemp, two_array_system):
+@pytest.mark.parametrize("model",
+                         ['faiman', 'pvsyst', 'sapm', 'fuentes', 'noct_sam'])
+def test_PVSystem_multi_array_celltemp_multi_temp(model, two_array_system):
     times = pd.date_range(start='2020-08-25 11:00', freq='H', periods=3)
     irrad = pd.Series(1000, index=times)
     temp_air_one = pd.Series(25, index=times)
     temp_air_two = pd.Series(5, index=times)
     wind_speed = pd.Series(1, index=times)
-    temp_one, temp_two = celltemp(
-        two_array_system,
+    temp_one, temp_two = two_array_system.get_cell_temperature(
         (irrad, irrad),
         (temp_air_one, temp_air_two),
-        wind_speed
+        wind_speed,
+        model=model
     )
     assert (temp_one != temp_two).all()
-    temp_one_swtich, temp_two_switch = celltemp(
-        two_array_system,
+    temp_one_swtich, temp_two_switch = two_array_system.get_cell_temperature(
         (irrad, irrad),
         (temp_air_two, temp_air_one),
-        wind_speed
+        wind_speed,
+        model=model
     )
     assert_series_equal(temp_one, temp_two_switch)
     assert_series_equal(temp_two, temp_one_swtich)
 
 
-@pytest.mark.parametrize("celltemp",
-                         [pvsystem.PVSystem.faiman_celltemp,
-                          pvsystem.PVSystem.pvsyst_celltemp,
-                          pvsystem.PVSystem.sapm_celltemp,
-                          pvsystem.PVSystem.fuentes_celltemp,
-                          pvsystem.PVSystem.noct_sam_celltemp])
-def test_PVSystem_multi_array_celltemp_multi_wind(celltemp, two_array_system):
+@pytest.mark.parametrize("model",
+                         ['faiman', 'pvsyst', 'sapm', 'fuentes', 'noct_sam'])
+def test_PVSystem_multi_array_celltemp_multi_wind(model, two_array_system):
     times = pd.date_range(start='2020-08-25 11:00', freq='H', periods=3)
     irrad = pd.Series(1000, index=times)
     temp_air = pd.Series(25, index=times)
     wind_speed_one = pd.Series(1, index=times)
     wind_speed_two = pd.Series(5, index=times)
-    temp_one, temp_two = celltemp(
-        two_array_system,
+    temp_one, temp_two = two_array_system.get_cell_temperature(
         (irrad, irrad),
         temp_air,
-        (wind_speed_one, wind_speed_two)
+        (wind_speed_one, wind_speed_two),
+        model=model
     )
     assert (temp_one != temp_two).all()
-    temp_one_swtich, temp_two_switch = celltemp(
-        two_array_system,
+    temp_one_swtich, temp_two_switch = two_array_system.get_cell_temperature(
         (irrad, irrad),
         temp_air,
-        (wind_speed_two, wind_speed_one)
+        (wind_speed_two, wind_speed_one),
+        model=model
     )
     assert_series_equal(temp_one, temp_two_switch)
     assert_series_equal(temp_two, temp_one_swtich)
 
 
-@pytest.mark.parametrize("celltemp",
-                         [pvsystem.PVSystem.faiman_celltemp,
-                          pvsystem.PVSystem.pvsyst_celltemp,
-                          pvsystem.PVSystem.sapm_celltemp,
-                          pvsystem.PVSystem.fuentes_celltemp,
-                          pvsystem.PVSystem.noct_sam_celltemp])
+@pytest.mark.parametrize("model",
+                         ['faiman', 'pvsyst', 'sapm', 'fuentes', 'noct_sam'])
 def test_PVSystem_multi_array_celltemp_temp_too_short(
-        celltemp, two_array_system):
+        model, two_array_system):
     with pytest.raises(ValueError,
                        match="Length mismatch for per-array parameter"):
-        celltemp(two_array_system, (1000, 1000), (1,), 1)
+        two_array_system.get_cell_temperature((1000, 1000), (1,), 1,
+                                              model=model)
 
 
-@pytest.mark.parametrize("celltemp",
-                         [pvsystem.PVSystem.faiman_celltemp,
-                          pvsystem.PVSystem.pvsyst_celltemp,
-                          pvsystem.PVSystem.sapm_celltemp,
-                          pvsystem.PVSystem.fuentes_celltemp,
-                          pvsystem.PVSystem.noct_sam_celltemp])
+@pytest.mark.parametrize("model",
+                         ['faiman', 'pvsyst', 'sapm', 'fuentes', 'noct_sam'])
 def test_PVSystem_multi_array_celltemp_temp_too_long(
-        celltemp, two_array_system):
+        model, two_array_system):
     with pytest.raises(ValueError,
                        match="Length mismatch for per-array parameter"):
-        celltemp(two_array_system, (1000, 1000), (1, 1, 1), 1)
+        two_array_system.get_cell_temperature((1000, 1000), (1, 1, 1), 1,
+                                              model=model)
 
 
-@pytest.mark.parametrize("celltemp",
-                         [pvsystem.PVSystem.faiman_celltemp,
-                          pvsystem.PVSystem.pvsyst_celltemp,
-                          pvsystem.PVSystem.sapm_celltemp,
-                          pvsystem.PVSystem.fuentes_celltemp,
-                          pvsystem.PVSystem.noct_sam_celltemp])
+@pytest.mark.parametrize("model",
+                         ['faiman', 'pvsyst', 'sapm', 'fuentes', 'noct_sam'])
 def test_PVSystem_multi_array_celltemp_wind_too_short(
-        celltemp, two_array_system):
+        model, two_array_system):
     with pytest.raises(ValueError,
                        match="Length mismatch for per-array parameter"):
-        celltemp(two_array_system, (1000, 1000), 25, (1,))
+        two_array_system.get_cell_temperature((1000, 1000), 25, (1,),
+                                              model=model)
 
 
-@pytest.mark.parametrize("celltemp",
-                         [pvsystem.PVSystem.faiman_celltemp,
-                          pvsystem.PVSystem.pvsyst_celltemp,
-                          pvsystem.PVSystem.sapm_celltemp,
-                          pvsystem.PVSystem.fuentes_celltemp,
-                          pvsystem.PVSystem.noct_sam_celltemp])
+@pytest.mark.parametrize("model",
+                         ['faiman', 'pvsyst', 'sapm', 'fuentes', 'noct_sam'])
 def test_PVSystem_multi_array_celltemp_wind_too_long(
-        celltemp, two_array_system):
+        model, two_array_system):
     with pytest.raises(ValueError,
                        match="Length mismatch for per-array parameter"):
-        celltemp(two_array_system, (1000, 1000), 25, (1, 1, 1))
+        two_array_system.get_cell_temperature((1000, 1000), 25, (1, 1, 1),
+                                              model=model)
 
 
-@pytest.mark.parametrize("celltemp",
-                         [pvsystem.PVSystem.faiman_celltemp,
-                          pvsystem.PVSystem.pvsyst_celltemp,
-                          pvsystem.PVSystem.sapm_celltemp,
-                          pvsystem.PVSystem.fuentes_celltemp,
-                          pvsystem.PVSystem.noct_sam_celltemp])
+@pytest.mark.parametrize("model",
+                         ['faiman', 'pvsyst', 'sapm', 'fuentes', 'noct_sam'])
 def test_PVSystem_multi_array_celltemp_poa_length_mismatch(
-        celltemp, two_array_system):
+        model, two_array_system):
     with pytest.raises(ValueError,
                        match="Length mismatch for per-array parameter"):
-        celltemp(two_array_system, 1000, 25, 1)
+        two_array_system.get_cell_temperature(1000, 25, 1, model=model)
 
 
 def test_PVSystem_fuentes_celltemp(mocker):
@@ -689,7 +665,7 @@ def test_PVSystem_fuentes_celltemp(mocker):
     temps = pd.Series(25, index)
     irrads = pd.Series(1000, index)
     winds = pd.Series(1, index)
-    out = system.fuentes_celltemp(irrads, temps, winds)
+    out = system.get_cell_temperature(irrads, temps, winds, model='fuentes')
     assert_series_equal(spy.call_args[0][0], irrads)
     assert_series_equal(spy.call_args[0][1], temps)
     assert_series_equal(spy.call_args[0][2], winds)
@@ -713,14 +689,14 @@ def test_PVSystem_fuentes_celltemp_override(mocker):
     temp_model_params = {'noct_installed': noct_installed}
     system = pvsystem.PVSystem(temperature_model_parameters=temp_model_params,
                                surface_tilt=20)
-    system.fuentes_celltemp(irrads, temps, winds)
+    system.get_cell_temperature(irrads, temps, winds, model='fuentes')
     assert spy.call_args[1]['surface_tilt'] == 20
 
     # can be overridden
     temp_model_params = {'noct_installed': noct_installed, 'surface_tilt': 30}
     system = pvsystem.PVSystem(temperature_model_parameters=temp_model_params,
                                surface_tilt=20)
-    system.fuentes_celltemp(irrads, temps, winds)
+    system.get_cell_temperature(irrads, temps, winds, model='fuentes')
     assert spy.call_args[1]['surface_tilt'] == 30
 
 
@@ -2185,3 +2161,23 @@ def test_Array_dc_ohms_from_percent(mocker):
                               '{"Vmpp", "Impp"}.')):
         array = pvsystem.Array(array_losses_parameters={'dc_ohmic_percent': 3})
         out = array.dc_ohms_from_percent()
+
+
+@pytest.mark.parametrize('funcname', ['sapm_celltemp', 'pvsyst_celltemp',
+                                      'faiman_celltemp', 'fuentes_celltemp',
+                                      'noct_sam_celltemp'])
+def test_PVSystem_temperature_deprecated(funcname):
+    temp_model_params = {
+        'a': -3.47, 'b': -0.0594, 'deltaT': 3,  # sapm
+        'noct_installed': 45,  # fuentes
+        'eta_m_ref': 0.2, 'noct': 45,  # noct_sam
+    }
+    system = pvsystem.PVSystem(temperature_model_parameters=temp_model_params)
+    func = getattr(system, funcname)
+    index = pd.date_range('2019-01-01', freq='h', periods=5)
+    temps = pd.Series(25, index)
+    irrads = pd.Series(1000, index)
+    winds = pd.Series(1, index)
+
+    with pytest.warns(pvlibDeprecationWarning):
+        func(irrads, temps, winds)

From df1e71212a2da35b6f01271e64707102bf7aed76 Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Wed, 14 Apr 2021 20:31:05 -0600
Subject: [PATCH 03/21] api.rst

---
 docs/sphinx/source/api.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/sphinx/source/api.rst b/docs/sphinx/source/api.rst
index 633a9d8cc0..5195febd78 100644
--- a/docs/sphinx/source/api.rst
+++ b/docs/sphinx/source/api.rst
@@ -239,6 +239,7 @@ PV temperature models
    temperature.fuentes
    temperature.ross
    temperature.noct_sam
+   pvsystem.PVSystem.get_cell_temperature
    pvsystem.PVSystem.sapm_celltemp
    pvsystem.PVSystem.pvsyst_celltemp
    pvsystem.PVSystem.faiman_celltemp

From 3b850b03704ab68c20fc3e426413649579c24f75 Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Wed, 14 Apr 2021 20:31:12 -0600
Subject: [PATCH 04/21] whatsnew

---
 docs/sphinx/source/whatsnew/v0.9.0.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/docs/sphinx/source/whatsnew/v0.9.0.rst b/docs/sphinx/source/whatsnew/v0.9.0.rst
index 9a8f3878b7..b68681bdea 100644
--- a/docs/sphinx/source/whatsnew/v0.9.0.rst
+++ b/docs/sphinx/source/whatsnew/v0.9.0.rst
@@ -67,6 +67,17 @@ Deprecations
   * ``ModelChain.weather``
   * ``ModelChain.times``
 
+* The following ``PVSystem`` cell temperature functions have been deprecated
+  and replaced with the wrapper method
+  :py:meth:`~pvlib.pvsystem.PVSystem.get_cell_temperature`:
+
+  * :py:meth:`~pvlist.pvsystem.PVSystem.sapm_celltemp`
+  * :py:meth:`~pvlist.pvsystem.PVSystem.pvsystem.PVSystem.pvsyst_celltemp`
+  * :py:meth:`~pvlist.pvsystem.PVSystem.pvsystem.PVSystem.faiman_celltemp`
+  * :py:meth:`~pvlist.pvsystem.PVSystem.pvsystem.PVSystem.fuentes_celltemp`
+  * :py:meth:`~pvlist.pvsystem.PVSystem.pvsystem.PVSystem.noct_sam_celltemp`
+
+
 Enhancements
 ~~~~~~~~~~~~
 * Add :func:`~pvlib.iotools.read_bsrn` for reading BSRN solar radiation data

From 42691d1e1d02f7f90389106d75070822fa26cced Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Wed, 14 Apr 2021 20:51:42 -0600
Subject: [PATCH 05/21] add test for invalid model string

---
 pvlib/tests/test_pvsystem.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/pvlib/tests/test_pvsystem.py b/pvlib/tests/test_pvsystem.py
index a7b37ad9d6..d50562a6dc 100644
--- a/pvlib/tests/test_pvsystem.py
+++ b/pvlib/tests/test_pvsystem.py
@@ -607,6 +607,12 @@ def test_PVSystem_multi_array_celltemp_multi_wind(model, two_array_system):
     assert_series_equal(temp_two, temp_one_swtich)
 
 
+def test_PVSystem_get_cell_temperature_invalid():
+    system = pvsystem.PVSystem()
+    with pytest.raises(ValueError, match='not a valid'):
+        system.get_cell_temperature(1000, 25, 1, 'not_a_model')
+
+
 @pytest.mark.parametrize("model",
                          ['faiman', 'pvsyst', 'sapm', 'fuentes', 'noct_sam'])
 def test_PVSystem_multi_array_celltemp_temp_too_short(

From e44cc26b014702384b7dccbd2844c28a71a4627d Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Wed, 14 Apr 2021 20:58:39 -0600
Subject: [PATCH 06/21] stickler, docs

---
 docs/sphinx/source/whatsnew/v0.9.0.rst |  2 +-
 pvlib/modelchain.py                    |  2 +-
 pvlib/pvsystem.py                      | 11 +++++++++++
 pvlib/tests/test_pvsystem.py           |  2 +-
 4 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/docs/sphinx/source/whatsnew/v0.9.0.rst b/docs/sphinx/source/whatsnew/v0.9.0.rst
index b68681bdea..46d0fd6d81 100644
--- a/docs/sphinx/source/whatsnew/v0.9.0.rst
+++ b/docs/sphinx/source/whatsnew/v0.9.0.rst
@@ -69,7 +69,7 @@ Deprecations
 
 * The following ``PVSystem`` cell temperature functions have been deprecated
   and replaced with the wrapper method
-  :py:meth:`~pvlib.pvsystem.PVSystem.get_cell_temperature`:
+  :py:meth:`~pvlib.pvsystem.PVSystem.get_cell_temperature` (:pull:`1211`):
 
   * :py:meth:`~pvlist.pvsystem.PVSystem.sapm_celltemp`
   * :py:meth:`~pvlist.pvsystem.PVSystem.pvsystem.PVSystem.pvsyst_celltemp`
diff --git a/pvlib/modelchain.py b/pvlib/modelchain.py
index 08a1ac7b91..9addb16ec6 100644
--- a/pvlib/modelchain.py
+++ b/pvlib/modelchain.py
@@ -1012,7 +1012,7 @@ def _set_celltemp(self, model):
         if model == 'noct_sam':
             kwargs['effective_irradiance'] = self.results.effective_irradiance
         self.results.cell_temperature = self.system.get_cell_temperature(
-                poa, temp_air, wind_speed, model=model, **kwargs)
+            poa, temp_air, wind_speed, model=model, **kwargs)
         return self
 
     def sapm_temp(self):
diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index 31dcc0aa56..65f5b94ea3 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -395,11 +395,22 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         wind_speed : numeric or tuple of numeric
             Wind speed in m/s.
 
+        model : str
+            Supported models include ``'sapm'``, ``'pvsyst'``,
+            ``'faiman'``, ``'fuentes'``, and ``'noct_sam'``
+
+        **kwargs
+            Extra arguments passed to the model function.
+
         Returns
         -------
         numeric or tuple of numeric
             values in degrees C.
 
+        See Also
+        --------
+        Array.get_cell_temperature
+
         Notes
         -----
         The `temp_air` and `wind_speed` parameters may be passed as tuples
diff --git a/pvlib/tests/test_pvsystem.py b/pvlib/tests/test_pvsystem.py
index d50562a6dc..5d1f412782 100644
--- a/pvlib/tests/test_pvsystem.py
+++ b/pvlib/tests/test_pvsystem.py
@@ -553,7 +553,7 @@ def test_PVSystem_multi_array_celltemp_functions(model, two_array_system):
     temp_air = pd.Series(25, index=times)
     wind_speed = pd.Series(1, index=times)
     temp_one, temp_two = two_array_system.get_cell_temperature(
-            (irrad_one, irrad_two), temp_air, wind_speed, model=model)
+        (irrad_one, irrad_two), temp_air, wind_speed, model=model)
     assert (temp_one != temp_two).all()
 
 

From e744b049f0bc055619c9f3a613b6d86ff64e5310 Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Thu, 15 Apr 2021 17:08:49 -0600
Subject: [PATCH 07/21] nudge to trigger CI

---
 docs/sphinx/source/whatsnew/v0.9.0.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/sphinx/source/whatsnew/v0.9.0.rst b/docs/sphinx/source/whatsnew/v0.9.0.rst
index 46d0fd6d81..b80892b0c1 100644
--- a/docs/sphinx/source/whatsnew/v0.9.0.rst
+++ b/docs/sphinx/source/whatsnew/v0.9.0.rst
@@ -67,8 +67,8 @@ Deprecations
   * ``ModelChain.weather``
   * ``ModelChain.times``
 
-* The following ``PVSystem`` cell temperature functions have been deprecated
-  and replaced with the wrapper method
+* The following ``PVSystem`` cell temperature methods have been deprecated
+  and consolidated into the new wrapper method
   :py:meth:`~pvlib.pvsystem.PVSystem.get_cell_temperature` (:pull:`1211`):
 
   * :py:meth:`~pvlist.pvsystem.PVSystem.sapm_celltemp`

From ec7b5fee431d098bb731e27edaaf5302bc0db3df Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Mon, 26 Apr 2021 17:07:12 -0600
Subject: [PATCH 08/21] fix whatsnew

---
 docs/sphinx/source/whatsnew/v0.9.0.rst | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/docs/sphinx/source/whatsnew/v0.9.0.rst b/docs/sphinx/source/whatsnew/v0.9.0.rst
index b80892b0c1..3d09deb5da 100644
--- a/docs/sphinx/source/whatsnew/v0.9.0.rst
+++ b/docs/sphinx/source/whatsnew/v0.9.0.rst
@@ -71,11 +71,11 @@ Deprecations
   and consolidated into the new wrapper method
   :py:meth:`~pvlib.pvsystem.PVSystem.get_cell_temperature` (:pull:`1211`):
 
-  * :py:meth:`~pvlist.pvsystem.PVSystem.sapm_celltemp`
-  * :py:meth:`~pvlist.pvsystem.PVSystem.pvsystem.PVSystem.pvsyst_celltemp`
-  * :py:meth:`~pvlist.pvsystem.PVSystem.pvsystem.PVSystem.faiman_celltemp`
-  * :py:meth:`~pvlist.pvsystem.PVSystem.pvsystem.PVSystem.fuentes_celltemp`
-  * :py:meth:`~pvlist.pvsystem.PVSystem.pvsystem.PVSystem.noct_sam_celltemp`
+  * :py:meth:`~pvlib.pvsystem.PVSystem.sapm_celltemp`
+  * :py:meth:`~pvlib.pvsystem.PVSystem.pvsyst_celltemp`
+  * :py:meth:`~pvlib.pvsystem.PVSystem.faiman_celltemp`
+  * :py:meth:`~pvlib.pvsystem.PVSystem.fuentes_celltemp`
+  * :py:meth:`~pvlib.pvsystem.PVSystem.noct_sam_celltemp`
 
 
 Enhancements

From 4c03c9366d555f95aeb3d06cbe2e948c178525c3 Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Tue, 11 May 2021 20:04:57 -0600
Subject: [PATCH 09/21] docstring fix

---
 pvlib/modelchain.py | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/pvlib/modelchain.py b/pvlib/modelchain.py
index 9addb16ec6..30f641f330 100644
--- a/pvlib/modelchain.py
+++ b/pvlib/modelchain.py
@@ -992,12 +992,9 @@ def _set_celltemp(self, model):
 
         Parameters
         ----------
-        model : function
-            A function that takes POA irradiance, air temperature, and
-            wind speed and returns cell temperature. `model` must accept
-            tuples or single values for each parameter where each element of
-            the tuple is the value for a different array in the system
-            (see :py:class:`pvlib.pvsystem.PVSystem` for more information).
+        model : str
+            A cell temperature model name to pass to
+            :py:meth:`pvlib.pvsystem.PVSystem.get_cell_temperature`.
 
         Returns
         -------

From 97e400d243f45dd90cdbc037340345ad9bb508de Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Tue, 11 May 2021 20:05:17 -0600
Subject: [PATCH 10/21] try out kinder error messages

---
 pvlib/pvsystem.py | 54 +++++++++++++++++++++++++++++------------------
 1 file changed, 33 insertions(+), 21 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index 65f5b94ea3..74130222f6 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -1482,13 +1482,26 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         Some temperature models have requirements for the input types;
         see the documentation of the underlying model function for details.
         """
+        def _build_args(keys):
+            try:
+                args = (self.temperature_model_parameters[key] for key in keys)
+            except KeyError as e:
+                missing_key = e.args[0]
+                msg = (f"Missing required parameter '{missing_key}'. Found "
+                       f"{self.temperature_model_parameters} in "
+                       "temperature_model_parameters.")
+                raise KeyError(msg)
+            return args
+
         if model == 'sapm':
             func = temperature.sapm_cell
-            params = _build_kwargs(['a', 'b', 'deltaT'],
-                                   self.temperature_model_parameters)
+            required = _build_args(['a', 'b', 'deltaT'])
+            optional = _build_kwargs(['irrad_ref'],
+                                     self.temperature_model_parameters)
         elif model == 'pvsyst':
             func = temperature.pvsyst_cell
-            params = {
+            required = tuple()
+            optional = {
                 **_build_kwargs(['eta_m', 'alpha_absorption'],
                                 self.module_parameters),
                 **_build_kwargs(['u_c', 'u_v'],
@@ -1496,34 +1509,33 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
             }
         elif model == 'faiman':
             func = temperature.faiman
-            params = _build_kwargs(['u0', 'u1'],
-                                   self.temperature_model_parameters)
+            required = tuple()
+            optional = _build_kwargs(['u0', 'u1'],
+                                     self.temperature_model_parameters)
         elif model == 'fuentes':
             func = temperature.fuentes
+            required = _build_args(['noct_installed'])
+            optional = _build_kwargs([
+                'module_height', 'wind_height', 'emissivity', 'absorption',
+                'surface_tilt', 'module_width', 'module_length'],
+                self.temperature_model_parameters)
             # default to using the Array attribute, but allow user to override
             # with a custom surface_tilt value in temperature_model_parameters
-            params = _build_kwargs([
-                'noct_installed', 'module_height', 'wind_height', 'emissivity',
-                'absorption', 'surface_tilt', 'module_width', 'module_length'],
-                self.temperature_model_parameters)
-            if 'surface_tilt' not in params:
-                params['surface_tilt'] = self.surface_tilt
+            if 'surface_tilt' not in kwargs:
+                kwargs['surface_tilt'] = self.surface_tilt
         elif model == 'noct_sam':
             func = temperature.noct_sam
-            params = _build_kwargs(['transmittance_absorptance', 'eta_m_ref',
-                                    'noct', 'array_height', 'mount_standoff'],
-                                   self.temperature_model_parameters)
-            if not {'noct', 'eta_m_ref'}.issubset(params):
-                msg = ('Parameters noct and eta_m_ref are required.'
-                       ' Found {} in temperature_model_parameters.'
-                       .format(self.temperature_model_parameters))
-                raise KeyError(msg)
+            required = _build_args(['noct', 'module_efficiency'])
+            optional = _build_kwargs(['transmittance_absorptance',
+                                      'array_height', 'mount_standoff'],
+                                     self.temperature_model_parameters)
         else:
             raise ValueError(f'{model} is not a valid cell temperature model')
 
         # allow kwargs to override
-        params.update(kwargs)
-        temperature_cell = func(poa_global, temp_air, wind_speed, **params)
+        optional.update(kwargs)
+        temperature_cell = func(poa_global, temp_air, wind_speed,
+                                *required, **optional)
         return temperature_cell
 
     def dc_ohms_from_percent(self):

From 2c0cd004e59f04ae6c3d8bfd92a115c3917589b4 Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Tue, 11 May 2021 20:43:40 -0600
Subject: [PATCH 11/21] fixing bugs

---
 pvlib/pvsystem.py            | 4 ++--
 pvlib/tests/test_pvsystem.py | 7 +++----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index 44887ba6d7..e3602643be 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -1523,8 +1523,8 @@ def _build_args(keys):
                 self.temperature_model_parameters)
             # default to using the Array attribute, but allow user to override
             # with a custom surface_tilt value in temperature_model_parameters
-            if 'surface_tilt' not in kwargs:
-                kwargs['surface_tilt'] = self.surface_tilt
+            if 'surface_tilt' not in optional:
+                optional['surface_tilt'] = self.surface_tilt
         elif model == 'noct_sam':
             func = temperature.noct_sam
             required = _build_args(['noct', 'module_efficiency'])
diff --git a/pvlib/tests/test_pvsystem.py b/pvlib/tests/test_pvsystem.py
index 7604752dfc..9db450c1cb 100644
--- a/pvlib/tests/test_pvsystem.py
+++ b/pvlib/tests/test_pvsystem.py
@@ -512,8 +512,7 @@ def test_PVSystem_noct_celltemp(mocker):
     out = system.get_cell_temperature(poa_global, temp_air, wind_speed,
                                       model='noct_sam')
     temperature.noct_sam.assert_called_once_with(
-        poa_global, temp_air, wind_speed, effective_irradiance=None, noct=noct,
-        module_efficiency=module_efficiency)
+        poa_global, temp_air, wind_speed, noct, module_efficiency)
     assert_allclose(out, expected)
     # different types
     out = system.get_cell_temperature(np.array(poa_global), np.array(temp_air),
@@ -678,7 +677,7 @@ def test_PVSystem_fuentes_celltemp(mocker):
     assert_series_equal(spy.call_args[0][0], irrads)
     assert_series_equal(spy.call_args[0][1], temps)
     assert_series_equal(spy.call_args[0][2], winds)
-    assert spy.call_args[1]['noct_installed'] == noct_installed
+    assert spy.call_args[0][3] == noct_installed
     assert_series_equal(out, pd.Series([52.85, 55.85, 55.85], index,
                                        name='tmod'))
 
@@ -2179,7 +2178,7 @@ def test_PVSystem_temperature_deprecated(funcname):
     temp_model_params = {
         'a': -3.47, 'b': -0.0594, 'deltaT': 3,  # sapm
         'noct_installed': 45,  # fuentes
-        'eta_m_ref': 0.2, 'noct': 45,  # noct_sam
+        'module_efficiency': 0.2, 'noct': 45,  # noct_sam
     }
     system = pvsystem.PVSystem(temperature_model_parameters=temp_model_params)
     func = getattr(system, funcname)

From cb85661e5b2fb847f9a750b79d144cfc7caf8501 Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Tue, 11 May 2021 20:43:52 -0600
Subject: [PATCH 12/21] test for nice error message

---
 pvlib/pvsystem.py            |  2 +-
 pvlib/tests/test_pvsystem.py | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index e3602643be..4be58a3e56 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -1484,7 +1484,7 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         """
         def _build_args(keys):
             try:
-                args = (self.temperature_model_parameters[key] for key in keys)
+                args = [self.temperature_model_parameters[key] for key in keys]
             except KeyError as e:
                 missing_key = e.args[0]
                 msg = (f"Missing required parameter '{missing_key}'. Found "
diff --git a/pvlib/tests/test_pvsystem.py b/pvlib/tests/test_pvsystem.py
index 9db450c1cb..49c7bd36df 100644
--- a/pvlib/tests/test_pvsystem.py
+++ b/pvlib/tests/test_pvsystem.py
@@ -2189,3 +2189,25 @@ def test_PVSystem_temperature_deprecated(funcname):
 
     with pytest.warns(pvlibDeprecationWarning):
         func(irrads, temps, winds)
+
+
+@pytest.mark.parametrize('model,keys', [
+    ('sapm', ('a', 'b', 'deltaT')),
+    ('fuentes', ('noct_installed',)),
+    ('noct_sam', ('noct', 'module_efficiency'))
+])
+def test_Array_temperature_missing_parameters(model, keys):
+    # test that a nice error is raised when required temp params are missing
+    array = pvsystem.Array()
+    index = pd.date_range('2019-01-01', freq='h', periods=5)
+    temps = pd.Series(25, index)
+    irrads = pd.Series(1000, index)
+    winds = pd.Series(1, index)
+
+    for key in keys:
+        match = f"Missing required parameter '{key}'"
+        params = {k: 1 for k in keys}  # dummy values
+        params.pop(key)  # remove each key in turn
+        array.temperature_model_parameters = params
+        with pytest.raises(KeyError, match=match):
+            array.get_cell_temperature(irrads, temps, winds, model)

From f01b9c19a36db163c2b6dd4da77844ad0612e51f Mon Sep 17 00:00:00 2001
From: Kevin Anderson <57452607+kanderso-nrel@users.noreply.github.com>
Date: Tue, 11 May 2021 20:44:27 -0600
Subject: [PATCH 13/21] Update pvlib/pvsystem.py

Co-authored-by: Cliff Hansen <cwhanse@sandia.gov>
---
 pvlib/pvsystem.py | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index 4be58a3e56..8db5e8a7e6 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -414,10 +414,9 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         Notes
         -----
         The `temp_air` and `wind_speed` parameters may be passed as tuples
-        to provide different values for each Array in the system. If not
-        passed as a tuple then the same value is used for input to each Array.
-        If passed as a tuple the length must be the same as the number of
-        Arrays.
+        to provide different values for each Array in the system. If passed as a
+        tuple the length must be the same as the number of Arrays. If not
+        passed as a tuple then the same value is used for each Array.
         """
         poa_global = self._validate_per_array(poa_global)
         temp_air = self._validate_per_array(temp_air, system_wide=True)

From 774807475b9ff67b77408af0f2d62d331dc7fe26 Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Tue, 11 May 2021 20:45:45 -0600
Subject: [PATCH 14/21] stickler

---
 pvlib/pvsystem.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index 8db5e8a7e6..634cffeb14 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -414,8 +414,8 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         Notes
         -----
         The `temp_air` and `wind_speed` parameters may be passed as tuples
-        to provide different values for each Array in the system. If passed as a
-        tuple the length must be the same as the number of Arrays. If not
+        to provide different values for each Array in the system. If passed as
+        a tuple the length must be the same as the number of Arrays. If not
         passed as a tuple then the same value is used for each Array.
         """
         poa_global = self._validate_per_array(poa_global)

From 4f03b08ec9ad60a9ac337fedc54045c5d4b86f5a Mon Sep 17 00:00:00 2001
From: Kevin Anderson <57452607+kanderso-nrel@users.noreply.github.com>
Date: Wed, 12 May 2021 10:13:43 -0600
Subject: [PATCH 15/21] Update pvlib/modelchain.py

Co-authored-by: Cliff Hansen <cwhanse@sandia.gov>
---
 pvlib/modelchain.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pvlib/modelchain.py b/pvlib/modelchain.py
index ec7f98b6c1..c661a0ec39 100644
--- a/pvlib/modelchain.py
+++ b/pvlib/modelchain.py
@@ -995,6 +995,7 @@ def _set_celltemp(self, model):
         model : str
             A cell temperature model name to pass to
             :py:meth:`pvlib.pvsystem.PVSystem.get_cell_temperature`.
+            Valid names are 'sapm', 'pvsyst', 'faiman', 'fuentes', 'noct_sam'
 
         Returns
         -------

From 0e59b30da86e2e4d4d6ac84ed350868663f02123 Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Thu, 13 May 2021 19:07:19 -0600
Subject: [PATCH 16/21] move _build_args to pvlib.tools

---
 pvlib/pvsystem.py | 23 ++++++++---------------
 pvlib/tools.py    | 28 +++++++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index 9a7e6fa127..19652a61d5 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -16,7 +16,7 @@
 
 from pvlib import (atmosphere, iam, inverter, irradiance,
                    singlediode as _singlediode, temperature)
-from pvlib.tools import _build_kwargs
+from pvlib.tools import _build_kwargs, _build_args
 
 
 # a dict of required parameter names for each DC power model
@@ -1472,20 +1472,13 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         Some temperature models have requirements for the input types;
         see the documentation of the underlying model function for details.
         """
-        def _build_args(keys):
-            try:
-                args = [self.temperature_model_parameters[key] for key in keys]
-            except KeyError as e:
-                missing_key = e.args[0]
-                msg = (f"Missing required parameter '{missing_key}'. Found "
-                       f"{self.temperature_model_parameters} in "
-                       "temperature_model_parameters.")
-                raise KeyError(msg)
-            return args
-
+        def _build_tcell_args(keys):
+            # convenience wrapper to avoid passing args 2 and 3 every call
+            return _build_args(keys, self.temperature_model_parameters,
+                               'temperature_model_parameters')
         if model == 'sapm':
             func = temperature.sapm_cell
-            required = _build_args(['a', 'b', 'deltaT'])
+            required = _build_tcell_args(['a', 'b', 'deltaT'])
             optional = _build_kwargs(['irrad_ref'],
                                      self.temperature_model_parameters)
         elif model == 'pvsyst':
@@ -1506,7 +1499,7 @@ def _build_args(keys):
                                      self.temperature_model_parameters)
         elif model == 'fuentes':
             func = temperature.fuentes
-            required = _build_args(['noct_installed'])
+            required = _build_tcell_args(['noct_installed'])
             optional = _build_kwargs([
                 'module_height', 'wind_height', 'emissivity', 'absorption',
                 'surface_tilt', 'module_width', 'module_length'],
@@ -1517,7 +1510,7 @@ def _build_args(keys):
                 optional['surface_tilt'] = self.surface_tilt
         elif model == 'noct_sam':
             func = temperature.noct_sam
-            required = _build_args(['noct', 'module_efficiency'])
+            required = _build_tcell_args(['noct', 'module_efficiency'])
             optional = _build_kwargs(['transmittance_absorptance',
                                       'array_height', 'mount_standoff'],
                                      self.temperature_model_parameters)
diff --git a/pvlib/tools.py b/pvlib/tools.py
index b6ee3e7c3a..eef80a3b37 100644
--- a/pvlib/tools.py
+++ b/pvlib/tools.py
@@ -230,7 +230,7 @@ def _build_kwargs(keys, input_dict):
     ----------
     keys : iterable
         Typically a list of strings.
-    adict : dict-like
+    input_dict : dict-like
         A dictionary from which to attempt to pull each key.
 
     Returns
@@ -249,6 +249,32 @@ def _build_kwargs(keys, input_dict):
     return kwargs
 
 
+def _build_args(keys, input_dict, dict_name):
+    """
+    Parameters
+    ----------
+    keys : iterable
+        Typically a list of strings.
+    input_dict : dict-like
+        A dictionary from which to pull each key.
+    dict_name : str
+        A variable name to include in an error message for missing keys
+
+    Returns
+    -------
+    kwargs : list
+        A list with values corresponding to keys
+    """
+    try:
+        args = [input_dict[key] for key in keys]
+    except KeyError as e:
+        missing_key = e.args[0]
+        msg = (f"Missing required parameter '{missing_key}'. Found "
+               f"{input_dict} in {dict_name}.")
+        raise KeyError(msg)
+    return args
+
+
 # Created April,2014
 # Author: Rob Andrews, Calama Consulting
 

From d5380372ff7060aab6077bbe415a4cad69fc6aac Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Fri, 14 May 2021 07:47:17 -0600
Subject: [PATCH 17/21] remove deprecated items from api.rst

---
 docs/sphinx/source/api.rst | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/docs/sphinx/source/api.rst b/docs/sphinx/source/api.rst
index 5195febd78..6cd644c588 100644
--- a/docs/sphinx/source/api.rst
+++ b/docs/sphinx/source/api.rst
@@ -240,11 +240,6 @@ PV temperature models
    temperature.ross
    temperature.noct_sam
    pvsystem.PVSystem.get_cell_temperature
-   pvsystem.PVSystem.sapm_celltemp
-   pvsystem.PVSystem.pvsyst_celltemp
-   pvsystem.PVSystem.faiman_celltemp
-   pvsystem.PVSystem.fuentes_celltemp
-   pvsystem.PVSystem.noct_sam_celltemp
 
 Temperature Model Parameters
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

From b97c04512d1f1bec7a84b95b9e95f86ac65318ca Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Fri, 14 May 2021 07:54:23 -0600
Subject: [PATCH 18/21] def -> partial

---
 pvlib/pvsystem.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index 19652a61d5..766edb82e6 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -1472,10 +1472,11 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         Some temperature models have requirements for the input types;
         see the documentation of the underlying model function for details.
         """
-        def _build_tcell_args(keys):
-            # convenience wrapper to avoid passing args 2 and 3 every call
-            return _build_args(keys, self.temperature_model_parameters,
-                               'temperature_model_parameters')
+        # convenience wrapper to avoid passing args 2 and 3 every call
+        _build_tcell_args = functools.partial(
+            _build_args, input_dict=self.temperature_model_parameters,
+            dict_name='temperature_model_parameters')
+
         if model == 'sapm':
             func = temperature.sapm_cell
             required = _build_tcell_args(['a', 'b', 'deltaT'])

From bb08d628533c57c7eca8817c14b69a20f82cdba4 Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Fri, 14 May 2021 07:54:46 -0600
Subject: [PATCH 19/21] docstring edits

---
 pvlib/pvsystem.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index 766edb82e6..f7fca95520 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -405,7 +405,7 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         Returns
         -------
         numeric or tuple of numeric
-            values in degrees C.
+            Values in degrees C.
 
         See Also
         --------
@@ -1465,7 +1465,12 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         Returns
         -------
         numeric
-            values in degrees C.
+            Values in degrees C.
+
+        See Also
+        --------
+        temperature.sapm_cell, temperature.pvsyst_cell, temperature.faiman,
+        temperature.fuentes, temperature.noct_sam
 
         Notes
         -----

From f50c7fe4d57ffc77d97ff8120183492d35ec38ee Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Fri, 14 May 2021 08:01:26 -0600
Subject: [PATCH 20/21] see also fixes

---
 pvlib/pvsystem.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index f7fca95520..dcffff6f43 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -1469,8 +1469,9 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
 
         See Also
         --------
-        temperature.sapm_cell, temperature.pvsyst_cell, temperature.faiman,
-        temperature.fuentes, temperature.noct_sam
+        pvlib.temperature.sapm_cell, pvlib.temperature.pvsyst_cell,
+        pvlib.temperature.faiman, pvlib.temperature.fuentes,
+        pvlib.temperature.noct_sam
 
         Notes
         -----

From 98c6776e2958c5e94eb204625e032495f4862bdc Mon Sep 17 00:00:00 2001
From: Kevin Anderson <kevin.anderson@nrel.gov>
Date: Fri, 14 May 2021 08:51:34 -0600
Subject: [PATCH 21/21] remove kwarg nonsense

---
 pvlib/pvsystem.py            | 43 +++++++++++++++---------------------
 pvlib/tests/test_pvsystem.py |  3 ++-
 2 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index dcffff6f43..487f7b953d 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -380,7 +380,7 @@ def get_iam(self, aoi, iam_model='physical'):
 
     @_unwrap_single_value
     def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
-                             **kwargs):
+                             effective_irradiance=None):
         """
         Determine cell temperature using the method specified by ``model``.
 
@@ -399,8 +399,9 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
             Supported models include ``'sapm'``, ``'pvsyst'``,
             ``'faiman'``, ``'fuentes'``, and ``'noct_sam'``
 
-        **kwargs
-            Extra arguments passed to the model function.
+        effective_irradiance : numeric or tuple of numeric, optional
+            The irradiance that is converted to photocurrent in W/m^2.
+            Only used for some models.
 
         Returns
         -------
@@ -421,25 +422,17 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         poa_global = self._validate_per_array(poa_global)
         temp_air = self._validate_per_array(temp_air, system_wide=True)
         wind_speed = self._validate_per_array(wind_speed, system_wide=True)
-
-        # additional model-specific (and array-specific) inputs
-        extra_inputs = [{}] * self.num_arrays
-
-        if 'effective_irradiance' in kwargs:
-            effective_irradiance = kwargs.pop('effective_irradiance')
-            if effective_irradiance is None:
-                effective_irradiance = tuple([None] * self.num_arrays)
-            else:
-                effective_irradiance = self._validate_per_array(
-                    effective_irradiance)
-            for inputs, value in zip(extra_inputs, effective_irradiance):
-                inputs['effective_irradiance'] = value
+        # Not used for all models, but Array.get_cell_temperature handles it
+        effective_irradiance = self._validate_per_array(effective_irradiance,
+                                                        system_wide=True)
 
         return tuple(
             array.get_cell_temperature(poa_global, temp_air, wind_speed,
-                                       model, **extra, **kwargs)
-            for array, poa_global, temp_air, wind_speed, extra in zip(
-                self.arrays, poa_global, temp_air, wind_speed, extra_inputs
+                                       model, effective_irradiance)
+            for array, poa_global, temp_air, wind_speed, effective_irradiance
+            in zip(
+                self.arrays, poa_global, temp_air, wind_speed,
+                effective_irradiance
             )
         )
 
@@ -1440,7 +1433,7 @@ 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,
-                             **kwargs):
+                             effective_irradiance=None):
         """
         Determine cell temperature using the method specified by ``model``.
 
@@ -1459,8 +1452,9 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
             Supported models include ``'sapm'``, ``'pvsyst'``,
             ``'faiman'``, ``'fuentes'``, and ``'noct_sam'``
 
-        **kwargs
-            Extra arguments passed to the model function.
+        effective_irradiance : numeric, optional
+            The irradiance that is converted to photocurrent in W/m^2.
+            Only used for some models.
 
         Returns
         -------
@@ -1516,7 +1510,8 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
             if 'surface_tilt' not in optional:
                 optional['surface_tilt'] = self.surface_tilt
         elif model == 'noct_sam':
-            func = temperature.noct_sam
+            func = functools.partial(temperature.noct_sam,
+                                     effective_irradiance=effective_irradiance)
             required = _build_tcell_args(['noct', 'module_efficiency'])
             optional = _build_kwargs(['transmittance_absorptance',
                                       'array_height', 'mount_standoff'],
@@ -1524,8 +1519,6 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         else:
             raise ValueError(f'{model} is not a valid cell temperature model')
 
-        # allow kwargs to override
-        optional.update(kwargs)
         temperature_cell = func(poa_global, temp_air, wind_speed,
                                 *required, **optional)
         return temperature_cell
diff --git a/pvlib/tests/test_pvsystem.py b/pvlib/tests/test_pvsystem.py
index 49c7bd36df..4b0badec00 100644
--- a/pvlib/tests/test_pvsystem.py
+++ b/pvlib/tests/test_pvsystem.py
@@ -512,7 +512,8 @@ def test_PVSystem_noct_celltemp(mocker):
     out = system.get_cell_temperature(poa_global, temp_air, wind_speed,
                                       model='noct_sam')
     temperature.noct_sam.assert_called_once_with(
-        poa_global, temp_air, wind_speed, noct, module_efficiency)
+        poa_global, temp_air, wind_speed, noct, module_efficiency,
+        effective_irradiance=None)
     assert_allclose(out, expected)
     # different types
     out = system.get_cell_temperature(np.array(poa_global), np.array(temp_air),