improvement on temperature windspeedfactor fix

pvdeg/fatigue.py

@@ -107,6 +107,7 @@ def solder_fatigue(
     b=0.33,
     C1=405.6,
     Q=0.12,
+    wind_speed_factor=None,
 ):
     """
     Get the Thermomechanical Fatigue of flat plate photovoltaic module solder joints.
@@ -169,7 +170,8 @@ def solder_fatigue(
         time_range = weather_df.index
 
     if temp_cell is None:
-        temp_cell = temperature.cell(weather_df, meta)
+        temp_cell = temperature.cell(weather_df=weather_df, meta=meta,
+                                     wind_speed_factor=wind_speed_factor)
 
     temp_amplitude, temp_max_avg = _avg_daily_temp_change(time_range, temp_cell)
 

pvdeg/temperature.py

@@ -25,12 +25,15 @@ def module(
          Contains keys/columns 'poa_global', 'poa_direct', 'poa_diffuse',
          'poa_sky_diffuse', 'poa_ground_diffuse'.
     temp_model : str, optional
-        The temperature model to use, Sandia Array Performance Model 'sapm' from pvlib by default.
+        The temperature model to use, Sandia Array Performance Model 'sapm'
+        from pvlib by default.
     conf : str, optional
-        The configuration of the PV module architecture and mounting configuration.
+        The configuration of the PV module architecture and mounting
+        configuration.
         Options:
-            'sapm': 'open_rack_glass_polymer' (default), 'open_rack_glass_glass',
-                    'close_mount_glass_glass', 'insulated_back_glass_polymer'
+            'sapm': 'open_rack_glass_polymer' (default),
+            'open_rack_glass_glass', 'close_mount_glass_glass',
+            'insulated_back_glass_polymer'
 
     Returns
     -------
@@ -53,14 +56,8 @@ def module(
     return module_temperature
 
 
-def cell(
-    weather_df, 
-    meta, 
-    poa=None, 
-    temp_model="sapm", 
-    conf="open_rack_glass_polymer", 
-    wind_speed_factor=1.7,
-):
+def cell(weather_df, meta, poa=None, temp_model="sapm",
+         conf="open_rack_glass_polymer", wind_speed_factor=None):
     """
     Calculate the PV cell temperature using PVLIB
     Currently this only supports the SAPM temperature model.
@@ -74,27 +71,45 @@ def cell(
     poa : (dataframe or series, optional)
         Dataframe or series with minimum requirement of 'poa_global'
     temp_model : (str, optional)
-        DO NOT CHANGE UNTIL UPDATED
+        Specify which temperature model from pvlib to use. Current options:
+        'sapm'
     conf : (str)
-        The configuration of the PV module architecture and mounting configuration.
+        The configuration of the PV module architecture and mounting
+        configuration.
         Options: 'open_rack_glass_polymer' (default), 'open_rack_glass_glass',
                  'close_mount_glass_glass', 'insulated_back_glass_polymer'
+    wind_speed_factor : (str)
+        Wind speed factor is a #KEMPE EXPLAIN HERE. Common values are 1.7 for
+        sapm. If None is passed, the function checks which algorithm for
+        temperature calculation is used and assigns it automatically.
 
     Return:
     -------
     temp_cell : pandas.DataFrame
-        This is the temperature of the cell in a module at every time step. [°C]
+        This is the temperature of the cell in a module at every time step.[°C]
     """
 
+    # TODO: if weather object passed is NSRDB data, use wind_seped_factor 1.7
+    # (and update description)
+    if wind_speed_factor is None:
+        if temp_model == "sapm":
+            wind_speed_factor = 1.7
+        else:
+            wind_speed_factor = 1.0
+
     parameters = pvlib.temperature.TEMPERATURE_MODEL_PARAMETERS[temp_model][conf]
 
     if poa is None:
         poa = pvdeg.spectral.poa_irradiance(weather_df, meta)
 
-    temp_cell = pvlib.temperature.sapm_cell(
-        poa_global=poa["poa_global"],
-        temp_air=weather_df["temp_air"],
-        wind_speed=weather_df["wind_speed"]* wind_speed_factor,
-        **parameters
-    )
+    if temp_model == 'sapm':
+        temp_cell = pvlib.temperature.sapm_cell(
+            poa_global=poa["poa_global"],
+            temp_air=weather_df["temp_air"],
+            wind_speed=weather_df["wind_speed"]*wind_speed_factor,
+            **parameters)
+    else:
+        # TODO: add options for temperature model
+        print("There are other models but they haven't been implemented yet!")
+
     return temp_cell

tests/test_fatigue.py

@@ -11,5 +11,6 @@ def test_solder_fatigue():
     # test solder fatique with default parameters
     # requires PSM3 weather file
 
-    damage = fatigue.solder_fatigue(weather_df=WEATHER, meta=META)
+    damage = fatigue.solder_fatigue(weather_df=WEATHER, meta=META,
+                                    wind_speed_factor=1.0)
     assert damage == pytest.approx(15.646, abs=0.005)