diff --git a/hub/catalog_factories/data_models/energy_systems/emission_system.py b/hub/catalog_factories/data_models/energy_systems/emission_system.py
index a8ac91b6..538954d3 100644
--- a/hub/catalog_factories/data_models/energy_systems/emission_system.py
+++ b/hub/catalog_factories/data_models/energy_systems/emission_system.py
@@ -10,7 +10,7 @@ class EmissionSystem:
   """
   Emission system class
   """
-  def __init__(self, system_id, model_name=None, system_type=None, parasitic_energy_consumption=None):
+  def __init__(self, system_id, model_name=None, system_type=None, parasitic_energy_consumption=0):
 
     self._system_id = system_id
     self._model_name = model_name