diff --git a/hub/catalog_factories/data_models/energy_systems/energy_storage_system.py b/hub/catalog_factories/data_models/energy_systems/energy_storage_system.py
index 6e746f35..e23d176c 100644
--- a/hub/catalog_factories/data_models/energy_systems/energy_storage_system.py
+++ b/hub/catalog_factories/data_models/energy_systems/energy_storage_system.py
@@ -58,7 +58,8 @@ class EnergyStorageSystem(ABC):
   @property
   def storage_type(self):
     """
-    Get storage type from ['electricity', 'thermal', 'chemical', 'lithium_ion', 'sensible', 'latent']
+    Get storage type from ['electricity', 'thermal', 'chemical',
+    'lithium_ion', 'lead_acid', 'NiCd', 'sensible', 'latent']
     :return: string
     """
     return self._storage_type
diff --git a/hub/catalog_factories/data_models/energy_systems/thermal_storage_system.py b/hub/catalog_factories/data_models/energy_systems/thermal_storage_system.py
index ea565e49..574ca24c 100644
--- a/hub/catalog_factories/data_models/energy_systems/thermal_storage_system.py
+++ b/hub/catalog_factories/data_models/energy_systems/thermal_storage_system.py
@@ -19,18 +19,18 @@ class ThermalStorageSystem(EnergyStorageSystem):
                volume, height, layers, maximum_operating_temperature):
 
     super().__init__(storage_id, name, model_name, manufacturer, storage_type, nominal_capacity, losses_ratio)
-    self._physical_volume = volume
+    self._volume = volume
     self._height = height
     self._layers = layers
     self._maximum_operating_temperature = maximum_operating_temperature
 
   @property
-  def physical_volume(self):
+  def volume(self):
     """
     Get the physical volume of the storage system in cubic meters
     :return: float
     """
-    return self._physical_volume
+    return self._volume
 
   @property
   def height(self):
@@ -69,7 +69,7 @@ class ThermalStorageSystem(EnergyStorageSystem):
       'storage type': self.storage_type,
       'nominal capacity [J]': self.nominal_capacity,
       'losses-ratio [J/J]': self.losses_ratio,
-      'physical volume [m3]': self.physical_volume,
+      'volume [m3]': self.volume,
       'height [m]': self.height,
       'layers': _layers,
       'maximum operating temperature [Celsius]': self.maximum_operating_temperature