diff --git a/VectoCore/Models/Declaration/ElectricSystem.cs b/VectoCore/Models/Declaration/ElectricSystem.cs
index 50bc1484a6e530b44c1bcacffc2ba651efa990e9..8aac710e1e7fc49b6c335f29f6f5ffcbfddc1e03 100644
--- a/VectoCore/Models/Declaration/ElectricSystem.cs
+++ b/VectoCore/Models/Declaration/ElectricSystem.cs
@@ -34,11 +34,11 @@ namespace TUGraz.VectoCore.Models.Declaration
 			var sum = _data[Tuple.Create(missionType, BaseLine)];
 
 			foreach (var s in technologies) {
-				if (_data.ContainsKey(Tuple.Create(missionType, s))) {
-					// todo: ask raphael why these technologies have to be subtracted?
-					sum -= _data[Tuple.Create(missionType, s)];
+				Watt w;
+				if (_data.TryGetValue(Tuple.Create(missionType, s), out w)) {
+					sum += w;
 				} else {
-					Log.Warn("electric system technology not found.");
+					Log.Error(string.Format("electric system technology not found: {0}", s));
 				}
 			}
 			return sum;
diff --git a/VectoCoreTest/Models/DeclarationDataTest.cs b/VectoCoreTest/Models/DeclarationDataTest.cs
index 612b5be2cf11fa6369ed76c2a035635e548a4356..5ac3cc38da82859a8dd6541c6c381951cc380556 100644
--- a/VectoCoreTest/Models/DeclarationDataTest.cs
+++ b/VectoCoreTest/Models/DeclarationDataTest.cs
@@ -100,11 +100,11 @@ namespace TUGraz.VectoCore.Tests.Models
 			var es = DeclarationData.ElectricSystem;
 
 			var expected = new[] {
-				new { Mission = MissionType.LongHaul, Base = 1240, LED = 1290 },
-				new { Mission = MissionType.RegionalDelivery, Base = 1055, LED = 1105 },
-				new { Mission = MissionType.UrbanDelivery, Base = 974, LED = 1024 },
-				new { Mission = MissionType.MunicipalUtility, Base = 974, LED = 1024 },
-				new { Mission = MissionType.Construction, Base = 975, LED = 1025 },
+				new { Mission = MissionType.LongHaul, Base = 1240, LED = 1190 },
+				new { Mission = MissionType.RegionalDelivery, Base = 1055, LED = 1005 },
+				new { Mission = MissionType.UrbanDelivery, Base = 974, LED = 924 },
+				new { Mission = MissionType.MunicipalUtility, Base = 974, LED = 924 },
+				new { Mission = MissionType.Construction, Base = 975, LED = 925 },
 				new { Mission = MissionType.HeavyUrban, Base = 0, LED = 0 },
 				new { Mission = MissionType.Urban, Base = 0, LED = 0 },
 				new { Mission = MissionType.Suburban, Base = 0, LED = 0 },