HVDC BorWin2 is a

high voltage direct current A high-voltage direct current (HVDC) electric power transmission system uses direct current (DC) for electric power transmission, in contrast with the more common alternating current (AC) transmission systems. Most HVDC links use voltages betwe ...

(HVDC) link built to transmit

offshore wind power Offshore wind power or offshore wind energy is the generation of electricity through wind farms in bodies of water, usually at sea. There are higher wind speeds offshore than on land, so offshore farms generate more electricity per amount of ca ...

to the

power grid ''Power Grid'' is the English-language version of the second edition of the multiplayer German-style board game ''Funkenschlag'', designed by Friedemann Friese and first released in 2004. ''Power Grid'' was released by Rio Grande Games. I ...

of the German mainland.Hussennether, V., Rittiger, J., Barth, A., Worthington, D., Dell’Anna, G., Rapetti, M., Hühnerbein, B., Siebert, M., Projects BorWin2 and HelWin1 – Large Scale Multilevel Voltage-Sourced Converter Technology for Bundling of Offshore Windpower, CIGRE Session 2012, Paris, paper reference B4-306. The project differs from most HVDC systems in that one of the two

converter stations Converter may refer to: Electromagnetics *Frequency converter *Voltage converter, another name for **Electromagnetic transformer **Switched-mode power supply **DC-to-DC converter **Power inverter (DC to AC) ***Solar inverter Electronics *Digita ...

is built on a platform in the sea. Voltage-Sourced Converters are used and the total cable length is 200 km. The project was completed by the

Siemens Siemens AG ( ) is a German multinational technology conglomerate. It is focused on industrial automation, building automation, rail transport and health technology. Siemens is the largest engineering company in Europe, and holds the positi ...

Prysmian Prysmian S.p.A. is a multinational company with headquarters in Milan, Italy, specialising in the production of electrical cable for use in the energy and telecom sectors and for optical fibres. Prysmian is present in Europe with 48 plants, 23 ...

consortium and handed over to its owner,

TenneT TenneT is a transmission system operator in the Netherlands and in a large part of Germany. ''TenneT B.V.'' is the national electricity transmission system operator of the Netherlands, headquartered in Arnhem. Controlled and owned by the Dutch ...

, in January 2015, becoming the first such project to be completed (the earlier HVDC BorWin1 project, despite having completed construction in 2009, was still not fully in service by that date).

Context

BorWin2 is part of an ambitious programme of providing grid connections to offshore wind parks off the coast of Germany, in the

German Bight The German Bight ( ; ; ); ; ; sometimes also the German Bay) is the southeastern bight of the North Sea bounded by the Netherlands and Germany to the south, and Denmark and Germany to the east (the Jutland peninsula). To the north and west i ...

, as part of the German

Energiewende The () is the ongoing energy transition by Germany. The new system intends to rely heavily on renewable energy (particularly wind, photovoltaics, and hydroelectricity), energy efficiency, and energy demand management. Legislative support for ...

(Energy Transition) programme. BorWin2 forms part of the ''BorWin cluster'', named after the German island of

Borkum Borkum (; ) is an island and a municipality in the Leer District in Lower Saxony, northwestern Germany. It is situated east of Rottumeroog and west of Juist. Geography Borkum is bordered to the west by the Westerems strait (which forms the ...

. BorWin2 has been built to transport power from the 400 MW

Veja Mate Veja may refer to : Places * Veja, a town in Lazio, central Italy; now Vejano comune * Veja, a village in Stănița Commune, Neamț County, Romania * Veja River, Romania * Veja State, a former princely state in present Gujarat, western India P ...

(using 6 MW Siemens gearless turbines) and Global Tech 1 wind parks.

HVDC A high-voltage direct current (HVDC) electric power transmission system uses direct current (DC) for electric power transmission, in contrast with the more common alternating current (AC) transmission systems. Most HVDC links use voltages betwe ...

has been chosen for most of the grid connections because the relatively long distance involved – both from the wind park to shore and from the shore to the nearest suitable connection point to the onshore grid - makes conventional alternating current transmission uneconomic.

Technical aspects

left, The land converter station at Diele.BorWin2 uses Voltage Sourced Converters (VSC) to convert from AC to DC and back again, using 4.5 kV IGBTs as the switching elements. One converter is provided at each end of the link with a DC voltage of ±300 kV and a transmission capacity of 800 MW. The converters, built by

, use the Modular Multi-Level Converter technology, in the

symmetrical monopole A high-voltage direct current (HVDC) electric power transmission system uses direct current (DC) for electric power transmission, in contrast with the more common alternating current (AC) transmission systems. Most HVDC links use voltages betwe ...

configuration. Each converter station is equipped with two, three-phase transformers, each rated at 590 MVA (offshore) and 585 MVA (onshore). Each converter valve is equipped with a dry-type valve reactor of 50 mH. The offshore converter is located on the BorWin Beta platform, which was built by Nordic Yards in

Warnemünde (, literally ''Mouth of the Warnow'') is a seaside resort and a district of the city of Rostock in Mecklenburg-Vorpommern, Mecklenburg, Germany. It is located on the Baltic Sea and, as the name implies, at the estuary of the river Warnow (river ...

. The ''topside'' of the platform is of the ''float-over'' type which is designed to be floated out to the installation site and then jacked up onto the submerged supporting structure using the support legs that are integral to the structure. The topside has a total weight of 12000 tonnes and measures 72.5 m x 51 m x 25 m high. Each of the two 300 kV cables linking BorWin Beta to the onshore substation has a total length of 200 km, of which 125 km is sea cable and 75 km is underground land cable. The cables cross the small island of

Norderney Norderney (; ) is one of the seven populated East Frisian Islands off the North Sea coast of Germany. The island is , having a total area of about and is therefore Germany's ninth-largest island. Norderney's population amounts to about 5,850 ...

and, having reached the mainland, continue, as land cables, to the onshore

converter station An HVDC converter station (or simply converter station) is a specialised type of substation which forms the terminal equipment for a high-voltage direct current (HVDC) transmission line.Arrillaga, Jos; High Voltage Direct Current Transmission, s ...

at Diele. The cables were supplied by

and use extruded

Cross-linked polyethylene Cross-linked polyethylene, commonly abbreviated PEX, XPE or XLPE, is a form of polyethylene with cross-links. It is used predominantly in building services pipework systems, hydronic radiant heating and cooling systems, domestic water piping, in ...

insulation.

Construction schedule

The BorWin2 project was ordered in 2010. The platform was installed in April 2014. Commissioning was completed in November 2014 and the project was handed over in January 2015.Successful Commissioning Of BorWin2 And HelWin1 HVDC Grid Connections
Realwire.com, 9 February 2015.

Connected wind farms

(402 MW) * Deutsche Bucht (252 MW) * Albatros (112 MW)

References

External links

Description of project
on

website (in German).
Description of project
on

website (in English).
Fact Sheet - BorWin2 HVDC Platform

website.
BorWin 2 HVDC system
{Dead link, date=January 2020 , bot=InternetArchiveBot , fix-attempted=yes , CIGRÉ Compendium of all HVDC Projects. Electrical interconnectors in the North Sea HVDC transmission lines Electric power transmission systems in Germany 2014 establishments in Germany Energy infrastructure completed in 2014