diff --git a/hub/city_model_structure/energy_systems/pv_generation_system.py b/hub/city_model_structure/energy_systems/pv_generation_system.py
index f6567c98..66ca7196 100644
--- a/hub/city_model_structure/energy_systems/pv_generation_system.py
+++ b/hub/city_model_structure/energy_systems/pv_generation_system.py
@@ -28,9 +28,7 @@ class PvGenerationSystem(GenerationSystem):
     self._height = None
     self._electricity_power_output = {}
     self._tilt_angle = None
-    self._surface_azimuth = None
-    self._solar_altitude_angle = None
-    self._solar_azimuth_angle = None
+    self._installed_capacity = None
 
   @property
   def nominal_electricity_output(self):
@@ -225,33 +223,17 @@ class PvGenerationSystem(GenerationSystem):
     self._electricity_power_output = value
 
   @property
-  def tilt_angle(self):
+  def installed_capacity(self):
     """
-    Get tilt angle of PV system in degrees
+    Get the total installed nominal capacity in W
     :return: float
     """
-    return self._tilt_angle
+    return self._installed_capacity
 
-  @tilt_angle.setter
-  def tilt_angle(self, value):
+  @installed_capacity.setter
+  def installed_capacity(self, value):
     """
-    Set PV system tilt angle in degrees
+    Set the total installed nominal capacity in W
     :param value: float
     """
-    self._tilt_angle = value
-
-  @property
-  def surface_azimuth(self):
-    """
-    Get surface azimuth angle of PV system in degrees. 0 is North
-    :return: float
-    """
-    return self._surface_azimuth
-
-  @surface_azimuth.setter
-  def surface_azimuth(self, value):
-    """
-    Set PV system tilt angle in degrees
-    :param value: float
-    """
-    self._surface_azimuth = value
+    self._installed_capacity = value
diff --git a/pv_assessment/pv_system_assessment.py b/pv_assessment/pv_system_assessment.py
index de83b4fd..72e1a3ae 100644
--- a/pv_assessment/pv_system_assessment.py
+++ b/pv_assessment/pv_system_assessment.py
@@ -188,6 +188,11 @@ class PvSystemAssessment:
     archetype_name = '_'.join(system_archetype_name.lower().split())
     if 'grid_tied' in archetype_name:
       self.results = self.grid_tied_system()
+    for energy_system in self.building.energy_systems:
+      for generation_system in energy_system.generation_systems:
+        if generation_system.system_type == cte.PHOTOVOLTAIC:
+          generation_system.installed_capacity = (self.results['rooftop_panels'] *
+                                                  float(generation_system.standard_test_condition_maximum_power))
     hourly_pv_output = self.results['total_hourly_pv_system_output_W']
     self.building.pv_generation[cte.HOUR] = hourly_pv_output
     self.building.pv_generation[cte.MONTH] = MonthlyValues.get_total_month(hourly_pv_output)