diff --git a/hub/city_model_structure/energy_systems/generic_energy_system.py b/hub/city_model_structure/energy_systems/generic_energy_system.py
index 45767ed7..350e3f0d 100644
--- a/hub/city_model_structure/energy_systems/generic_energy_system.py
+++ b/hub/city_model_structure/energy_systems/generic_energy_system.py
@@ -5,11 +5,12 @@ Copyright © 2023 Concordia CERC group
 Project Coder Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
 """
 
-from typing import Union
+from typing import Union, List
 
 from hub.city_model_structure.energy_systems.generic_generation_system import GenericGenerationSystem
 from hub.city_model_structure.energy_systems.generic_distribution_system import GenericDistributionSystem
 from hub.city_model_structure.energy_systems.generic_emission_system import GenericEmissionSystem
+from hub.city_model_structure.city_object import CityObject
 
 
 class GenericEnergySystem:
@@ -21,6 +22,7 @@ class GenericEnergySystem:
     self._generation_system = None
     self._distribution_system = None
     self._emission_system = None
+    self._connected_city_objects = None
 
   @property
   def demand_types(self):
@@ -44,16 +46,9 @@ class GenericEnergySystem:
     Get generation system
     :return: GenerationSystem
     """
+    self._generation_system = GenericGenerationSystem(self.connected_city_objects)
     return self._generation_system
 
-  @generation_system.setter
-  def generation_system(self, value):
-    """
-    Set generation system
-    :param value: GenerationSystem
-    """
-    self._generation_system = value
-
   @property
   def distribution_system(self) -> Union[None, GenericDistributionSystem]:
     """
@@ -85,3 +80,19 @@ class GenericEnergySystem:
     :param value: EmissionSystem
     """
     self._emission_system = value
+
+  @property
+  def connected_city_objects(self) -> Union[None, List[CityObject]]:
+    """
+    Get list of city objects that are connected to this energy system
+    :return: List[CityObject]
+    """
+    return self._connected_city_objects
+
+  @connected_city_objects.setter
+  def connected_city_objects(self, value):
+    """
+    Set list of city objects that are connected to this energy system
+    :param value: List[CityObject]
+    """
+    self._connected_city_objects = value
diff --git a/hub/city_model_structure/energy_systems/generic_generation_system.py b/hub/city_model_structure/energy_systems/generic_generation_system.py
index 64fa35b5..1d19ea5c 100644
--- a/hub/city_model_structure/energy_systems/generic_generation_system.py
+++ b/hub/city_model_structure/energy_systems/generic_generation_system.py
@@ -8,17 +8,20 @@ Project Coder Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
 from __future__ import annotations
 from typing import Union
 
+import hub.helpers.constants as cte
+
 
 class GenericGenerationSystem:
   """
   GenericGenerationSystem class
   """
-  def __init__(self):
+  def __init__(self, city_objects=None, heat_power=None, cooling_power=None, electricity_power=None):
+    self._city_objects = city_objects
     self._type = None
     self._fuel_type = None
-    self._heat_power = None
-    self._cooling_power = None
-    self._electricity_power = None
+    self._heat_power = heat_power
+    self._cooling_power = cooling_power
+    self._electricity_power = electricity_power
     self._source_types = None
     self._heat_efficiency = None
     self._cooling_efficiency = None
@@ -84,48 +87,46 @@ class GenericGenerationSystem:
     Get heat_power in W
     :return: float
     """
+    if self._heat_power is None:
+      self._heat_power = 0
+      for city_object in self._city_objects:
+        if city_object.heating_peak_load is not None:
+          if self.peak_coverages[cte.HEATING] is None:
+            return None
+          self._heat_power += city_object.heating_peak_load[cte.YEAR][0] * self.peak_coverages[cte.HEATING]
     return self._heat_power
 
-  @heat_power.setter
-  def heat_power(self, value):
-    """
-    Set heat_power in W
-    :param value: float
-    """
-    self._heat_power = value
-
   @property
   def cooling_power(self):
     """
     Get cooling_power in W
     :return: float
     """
+    if self._cooling_power is None:
+      self._cooling_power = 0
+      for city_object in self._city_objects:
+        if city_object.cooling_peak_load is not None:
+          if self.peak_coverages[cte.COOLING] is None:
+            return None
+          self._cooling_power += city_object.cooling_peak_load[cte.YEAR][0] * self.peak_coverages[cte.COOLING]
     return self._cooling_power
 
-  @cooling_power.setter
-  def cooling_power(self, value):
-    """
-    Set cooling_power in W
-    :param value: float
-    """
-    self._cooling_power = value
-
   @property
   def electricity_power(self):
     """
     Get electricity_power in W
     :return: float
     """
+    if self._electricity_power is None:
+      self._electricity_power = 0
+      for city_object in self._city_objects:
+        if city_object.electricity_peak_load is not None:
+          if self.peak_coverages[cte.ELECTRICITY] is None:
+            return None
+          self._electricity_power += city_object.electricity_peak_load[cte.YEAR][0]\
+                                     * self.peak_coverages[cte.ELECTRICITY]
     return self._electricity_power
 
-  @electricity_power.setter
-  def electricity_power(self, value):
-    """
-    Set electricity_power in W
-    :param value: float
-    """
-    self._electricity_power = value
-
   @property
   def heat_efficiency(self):
     """
@@ -214,14 +215,6 @@ class GenericGenerationSystem:
     """
     return self._storage_capacity
 
-  @storage_capacity.setter
-  def storage_capacity(self, value):
-    """
-    Set storage_capacity in J
-    :param value: float
-    """
-    self._storage_capacity = value
-
   @property
   def storage(self):
     """
@@ -246,14 +239,6 @@ class GenericGenerationSystem:
     """
     return self._auxiliary_equipment
 
-  @auxiliary_equipment.setter
-  def auxiliary_equipment(self, value):
-    """
-    Set auxiliary_equipment
-    :param value: GenerationSystem
-    """
-    self._auxiliary_equipment = value
-
   @property
   def peak_coverages(self) -> dict:
     """