The connection between genius and solitude has often been remarked upon. Albert Einstein and Friedrich Nietzsche both dreamed up world-altering theories in the mountains of Switzerland while the Greek Diogenes developed his cynical philosophy from within the confines of a barrel.

That solitary philosophy seems to be shared by Hans-Bernd Menzel, chief executive of the European Energy Exchange, who has turned his company into the continent's biggest power market from the unlikely environs of Leipzig, in the German state of Saxony.