Honestly. If they ever add the Elefant/Ferdinand I could see this being an event that comes with it.
Like the TT comes with the Ferdinand while the premium comes with the improved Elefant (New cupola, slightly more armour due to new hull MG and Hull MG) and then make this a event reward since it was used as the command for a Ferdinand unit.
A tank powered by an electric engine.
It was a major milestone in both vehicle and tank history but ultimately the concept was far more advanced then technology of the era itself thus was doomed to fail.