diff --git a/CHANGELOG.md b/CHANGELOG.md
index 361e0c27f9..8d0745befe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -110,6 +110,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Refactoring to only use 'lastHpState' and 'relevantData' for 'ThermalGrid' calculations [#916](https://github.com/ie3-institute/simona/issues/916)
 - Refactor thermal calcRelevantData [#1051](https://github.com/ie3-institute/simona/issues/1051)
 - Removed Deployment stage from Jenkinsfile [#1063](https://github.com/ie3-institute/simona/issues/1063)
+- Prepare 'ChpModelSpec' and 'CylindricalThermalStorageSpec' for Storage without storageVolumeLvlMin [#1012](https://github.com/ie3-institute/simona/issues/1012)
 
 ### Fixed
 - Fix rendering of references in documentation [#505](https://github.com/ie3-institute/simona/issues/505)
diff --git a/src/main/scala/edu/ie3/simona/model/thermal/MutableStorage.scala b/src/main/scala/edu/ie3/simona/model/thermal/MutableStorage.scala
index 785c5c4d47..6854883720 100644
--- a/src/main/scala/edu/ie3/simona/model/thermal/MutableStorage.scala
+++ b/src/main/scala/edu/ie3/simona/model/thermal/MutableStorage.scala
@@ -53,6 +53,7 @@ trait MutableStorage {
     * @return
     *   lack
     */
+  @deprecated("Use thermal storage state instead")
   def tryToTakeAndReturnLack(
       takenEnergy: Energy
   ): Option[Energy]
diff --git a/src/test/scala/edu/ie3/simona/model/participant/ChpModelSpec.scala b/src/test/scala/edu/ie3/simona/model/participant/ChpModelSpec.scala
index c664788dae..26eb66e314 100644
--- a/src/test/scala/edu/ie3/simona/model/participant/ChpModelSpec.scala
+++ b/src/test/scala/edu/ie3/simona/model/participant/ChpModelSpec.scala
@@ -264,7 +264,7 @@ class ChpModelSpec
           92,
           1,
           1150,
-        ), // test case (true, true, true) and storage volume exceeds maximum
+        ), // test case (true, true, true) CHP running, storage at lvl 92 (1058 kWh) + 100 kWh from CHP exceeds max capacity (1150 kWh).
       )
 
       forAll(testCases) {
diff --git a/src/test/scala/edu/ie3/simona/model/thermal/CylindricalThermalStorageSpec.scala b/src/test/scala/edu/ie3/simona/model/thermal/CylindricalThermalStorageSpec.scala
index d2c2a15ee7..8936620e6a 100644
--- a/src/test/scala/edu/ie3/simona/model/thermal/CylindricalThermalStorageSpec.scala
+++ b/src/test/scala/edu/ie3/simona/model/thermal/CylindricalThermalStorageSpec.scala
@@ -110,7 +110,7 @@ class CylindricalThermalStorageSpec
       val storage = buildThermalStorage(storageInput, CubicMeters(70))
 
       val usableThermalEnergy = storage.usableThermalEnergy
-      usableThermalEnergy should approximate(KilowattHours(5 * 115 + 230))
+      usableThermalEnergy should approximate(KilowattHours(805))
     }
 
     "Apply, validation, and build method work correctly" in {
@@ -232,7 +232,7 @@ class CylindricalThermalStorageSpec
           "expectedStoredEnergy",
         ),
         (0L, 250.0, 10.0, 3600L, 0.0, 260.0),
-        (0L, 250.0, -10.0, 3600L, 0.0, 240.0),
+        (0L, 20.0, -10.0, 3600L, 0.0, 10.0),
       )
 
       forAll(cases) {