--- a/src/energy/model/energy-source.cc	Sun Mar 29 16:08:40 2015 +0200
+++ b/src/energy/model/energy-source.cc	Sun Mar 29 16:12:50 2015 +0200
@@ -37,6 +37,7 @@
 {
   static TypeId tid = TypeId ("ns3::EnergySource")
     .SetParent<Object> ()
+    .SetGroupName ("Energy")
   ;
   return tid;
 }