Issue 10/08
HVDC/FACTS - Highlights
http://www.siemens.com/FACTS
http://www.siemens.com/HVDC
WIPOS™ - The new Wind Power Offshore Substation
from Siemens
The world of energy is changing rapidly. New demands on networks pose new challenges, and Siemens
answers. More distributed generation, remote renewable sources, and shifting patterns of energy usage mean
networks must perform like never before. Existing AC networks need to be stabilized and improved, for example
with FACTS (flexible AC transmission systems) technology and long distance transmission requires low loss
HVDC (high voltage direct current). Siemens supplies a comprehensive range of reliable, efficient, and proven
grid access solutions that help overcome such challenges. In the new world of offshore connections, Siemens
has taken the early lead. Siemens offers comprehensive turnkey grid access solutions ranging from first
feasibility and power system studies to the engineering, procurement, construction, and commissioning of entire
grid connections.
WIPOS™
The latest brand in the grid access portfolio is the Siemens
Wind Power Offshore Substation (WIPOS™). It is the optimal
solution that ensures long life for offshore substations. With
WIPOS, Siemens marks an innovative role in the design,
engineering and installation of offshore platforms for wind
farms.
WIPOS serves as an interface between the Wind turbines
and the mainland whereby power harvested from wind
passes through on to the cables to reach the point of
common connection onshore.
In the offshore wind industry, the word ‘platform’ reflects two
construction entities namely the ‘topside’ and the ‘foundation’
entity which serves as the base for the topside.
The topside comprises a multi-deck construction where all
electro-technical equipment like AC/DC vitals, low-medium
and high voltage equipment as well as DC converters are
installed thus forming an Offshore Substation. The substation
could be used to transmit either AC or DC depending on the Fig. 1: Siemens Wind Power Offshore Substation
(WIPOS™) – a model
distance from shore.
Siemens offers a family of WIPOS design with the flexibility to meet various offshore weather, tide and seabed
conditions namely:
• WIPOS- Self Lifting Solution
• WIPOS- Topside Solution (Topside/Jacket)
• WIPOS- Floating Solution
Self Lifting Solution
As the name implies the platform structure lifts itself. The topside comprises a pontoon with hollow tubular legs
which are immersed and fastened on a base frame (foundation) thus allowing vertical suspension. Minimal
installation efforts are allocated for this solution and Heavy Crane Vessels are not necessary.
Issue 10/08
HVDC/FACTS - Highlights
It is going to be installed for the latest
order “BorWin2“ which Siemens has
received from transpower, Germany
(Press Release). For the project
BorWin2, Siemens will also supply
the world’s largest voltage sourced
converter (VSC) system – using
Siemens HVDC PLUS technology –
with a rating of 800 MW. The wind
farms Veja Mate and Global Tech 1
are designed to generate 800 MW of
renewabe power and will be
connected through Siemens’ HVDC
PLUS link to shore. The converter
will be installed on an offshore
platform, where the voltage level will
be stepped up from 155 to 300 kV
AC and then converted to DC at the
same voltage level. The Siemens
Wind Power Offshore Substation
Fig. 2: WIPOS- Self Lifting Solution
(WIPOS), designed as a floating,
self-lifting platform, will accommodate all the requisite electrical equipment for the HVDC converter, primarily the
converter itself, two transformers, four AC cable compensation reactors and high-voltage gas-insulated
switchgear (GIS). The wind power will be transported via submarine and land cable to Diele close by Papenburg,
where an onshore substation will reconvert it from DC to AC for further transmission and distribution within the
400 kV AC grid. The whole transmission link is expected to begin operation in 2013.
Topside / Jacket Solution
In this configuration, the topside and foundation structures are two separate entities.
Fig. 3: WIPOS- Topside Solution
(Topside/Jacket)
Fig. 4: Greater Gabbard platform - Example of an open design in
UK with standard topside and jacket solution
It is used for the Greater Gabbard project (Magazine: Living Energy) in United Kingdom roughly 25 kilometers
off the coast of Suffolk.
Issue 10/08
HVDC/FACTS - Highlights
Floating Solution
The floating solution incorporates a floating facility with excessive buoyancy that could be completely floating or
held in place by anchors connected to a catenary mooring system on the seabed depending on water depth.
Through WIPOS, Siemens offers optimized designs for both entities by joining workforces with offshore,
maritime, and shipyard experts. It is an all-round solution featuring configuration flexibility to meet offshore
weather and seabed conditions.
Prospects of the market
Europe is evermore proving its leading position in the offshore industry with the newly plan Seatec. The North
Seas Countries’ Offshore Grid Initiative is a large scale green energy project to develop offshore wind energy
prospects. Germany along with eight countries namely Ireland, Great Britain, the Netherlands, Belgium,
Luxemburg, Denmark, Norway und Sweden have signed the North Seas Countries’ Offshore Grid Initiative
Declaration.
They plan to connect offshore wind turbines to the grid within the next 10 years for the North Sea and the Baltic
Sea. That includes interconnecting wind farms off the German and British coasts, the Netherlands and Denmark
to each other with cables that go from the sea farms to the coasts.
The plan includes connecting hydroelectric power stations of non-EU member Norway to the European network.
Hydroelectric power is urgently needed to supplement wind energy and to ensure a stable supply of electricity
and pave the way for supplying green electricity to meet basic power requirements.
Fig. 5: Seatec
Right now, wind power contributes around 10 percent of Europe’s electricity supply. The European Network of
Transmission System Operators for Electricity (ENTSO-E) estimates that wind power’s share needs to be tripled
to meet the EU’s climate protection targets. According to statistics published by the European Wind Energy
Association (EWEA), wind farms with a total capacity of more than 100 gigawatts are in the process of being
planned. The sea network could be completed by 2020.