The HelWin2 platform is located 85 kilometres off the German coast in the North Sea.
Construction of the platform was completed in July 2014 and will initially only serve E.on's 288MW Amrumbank West project.
Amrumbank West achieved first power in April 2015. It uses 80 Siemens 3.6MW turbines at the site.
HelWin2's addition means Siemens has added 2.9GW of transmission links to the German grid in 2015.
Siemens is still working on the 900MW BorWin3 project for Tennet. It is set to be commissione in 2019.