Merge pull request #375 from NREL/hour_angle_filter

Hour angle filter

rdtools/analysis_chains.py

@@ -236,10 +236,10 @@ def _calc_clearsky_poa(self, times=None, rescale=True, **kwargs):
                                   freq='1min')
             aggregate = True
 
-        if self.pvlib_location is None:
+        if not hasattr(self, 'pvlib_location'):
             raise ValueError(
                 'pvlib location must be provided using set_clearsky()')
-        if self.pv_tilt is None or self.pv_azimuth is None:
+        if not hasattr(self, 'pv_tilt') or not hasattr(self, 'pv_azimuth'):
             raise ValueError(
                 'pv_tilt and pv_azimuth must be provided using set_clearsky()')
 
@@ -332,9 +332,9 @@ def _calc_clearsky_tamb(self):
         Calculate clear-sky ambient temperature and store in self.temperature_ambient_clearsky
         '''
         times = self.poa_global_clearsky.index
-        if self.pvlib_location is None:
+        if not hasattr(self, 'pvlib_location'):
             raise ValueError(
-                'pvlib location must be provided using set_clearsky()')
+                'pvlib_location must be provided using set_clearsky()')
         loc = self.pvlib_location
 
         cs_amb_temp = clearsky_temperature.get_clearsky_tamb(
@@ -464,6 +464,18 @@ def _call_clearsky_filter(filter_string):
             f = filtering.clip_filter(
                 self.pv_power, **self.filter_params['clip_filter'])
             filter_components['clip_filter'] = f
+        if 'hour_angle_filter' in self.filter_params:
+            if not hasattr(self, 'pvlib_location'):
+                raise ValueError(
+                    'The pvlib location must be provided using set_clearsky() '
+                    'or by directly setting TrendAnalysis.pvlib_location '
+                    'in order to use the hour_angle_filter')
+            loc = self.pvlib_location
+            f = filtering.hour_angle_filter(
+                energy_normalized, loc.latitude, loc.longitude,
+                 **self.filter_params['hour_angle_filter'])
+            filter_components['hour_angle_filter'] = f
+
         if case == 'clearsky':
             filter_components['pvlib_clearsky_filter'] = _call_clearsky_filter('pvlib_clearsky_filter')
         if 'sensor_pvlib_clearsky_filter' in self.filter_params:

rdtools/filtering.py

@@ -948,3 +948,18 @@ def directional_tukey_filter(series, roll_period=pd.to_timedelta('7 Days'), k=1.
             ((backward_dif > backward_dif_lower) & (backward_dif < backward_dif_upper))
             )
     return mask
+
+
+def hour_angle_filter(series, lat, lon, min_hour_angle=-30, max_hour_angle=30):
+    '''
+    Creates a filter based on the hour angle of the sun (15 degrees per hour)
+    '''
+
+    times = series.index
+    spa = pvlib.solarposition.get_solarposition(times, lat, lon)
+    eot = spa['equation_of_time']
+    hour_angle = pvlib.solarposition.hour_angle(times, lon, eot)
+    hour_angle = pd.Series(hour_angle, index=times)
+    mask = (hour_angle >= min_hour_angle) & (hour_angle <= max_hour_angle)
+
+    return mask

requirements.txt

@@ -18,7 +18,7 @@ pvlib==0.9.0
 pyparsing==2.4.7
 python-dateutil==2.8.1
 pytz==2019.3
-arch==4.11
+arch==5.5.0
 filterpy==1.4.5
 requests==2.25.1
 retrying==1.3.3