Siemens Wins Maintenance Contracts for Offshore Electric Grid Connections in the North Sea

Successful entry into the maintenance market for German offshore wind farm connections

After having won the orders to build the two North Sea grid connections HelWin1 and
BorWin2 in the summer of this year, Siemens has now also been contracted to carry out
their entire maintenance. The two contracts, awarded by the Dutch grid operator TenneT,
are Siemens' first in the emerging field of offshore grid connection maintenance services
within Germany and are initially for a period of five years. The two connections provide
transfer capacity to the German mainland for several offshore wind farms in the North Sea.
Siemens will establish a service base in Lower Saxony close to the coastline for the
offshore and onshore converter stations. This enables Siemens to further expand its
comprehensive operation & maintenance service portfolio for electricity transmission grids.

"The BorWin 2 and HelWin1 projects for integration of the offshore wind farms Veja Mate, Global
Tech I and Nordsee Ost into the onshore high-voltage transmission grid will benefit from our many
years of experience in this field. As the undisputed market leader, we have so far received orders
for connecting offshore wind farms with a rating totaling approximately 4,800 megawatts. Now we
are going to aggressively develop our maintenance business in this field as well", says Dr. Udo
Niehage, CEO of the Power Transmission Division within the Energy Sector at Siemens.

The services covered by the contract include preparing the maintenance schedules, coordinating
and executing inspections, preventive maintenances and repairs, and providing the related
logistics and spare parts management services. To ensure fast customer response, Siemens will
set up a service base in Lower Saxony close to the coastline and will staff it with highly qualified
personnel. The wind farms are located between 85 and 125 kilometers offshore, to the north-west
of the islands of Borkum and Helgoland, and pose special challenges in terms of maintenance and
logistics due to their exposure to a harsh maritime environment. The BorWin2 grid connection will
have a transmission capacity of up to 800 megawatts (MW) of clean electric power, HelWin1 a capacity of 576 MW. Both connections will be built using high-voltage direct current (HVDC)
transmission technology with submarine cables, and are scheduled to be ready for operation in

Using HVDC technology reduces transmission losses significantly. High-voltage cable links more
than 80 kilometers long require HVDC for power transmission due to the fact that a major portion of
the electrical energy would be lost as reactive power with an AC connection of that length and
power rating. Siemens has developed HVDC Plus for precisely such applications. This modular
VSC technology reduces the complexity and thus the installation space needed at offshore

The Siemens Energy Sector is the world's leading supplier of a complete spectrum of products, services and solutions
for the generation, transmission and distribution of power and for the extraction, conversion and transport of oil and gas.
In fiscal 2009 (ended September 30), the Energy Sector had revenues of approximately EUR25.8 billion and received
new orders totaling approximately EUR30 billion and posted a profit of EUR3.3 billion. On September 30, 2009, the
Energy Sector had a work force of more than 85,100. Further information is available at:

Siemens AG
Corporate Communications and Government Affairs
Wittelsbacherplatz 2, 80333 Munich

Media Relations: Torsten Wolf
Telephone: +49 9131 18-82532

Siemens AG
Energy Sector - Power Transmission Division
Freyeslebenstr. 1, 91058 Erlangen, Germany

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