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.
The HVDC Cross-Channel is the 73 km long high-voltage direct current (HVDC) interconnector that operates since 1986 under the English Channel between the continental European grid at Bonningues-lès-Calais and the British electricity grid at Sellindge. The cable is also known as IFA, and should not be confused with the new IFA-2, another interconnect with France that is three times as long but only half as powerful.
The HVDC Rihand–Delhi is a HVDC connection between Rihand and Dadri in India, put into service in 1990. It connects the 3,000 MW coal-based Rihand Thermal Power Station in Uttar Pradesh to the northern region of India. The project has an 814 kilometres (506 mi) long bipolar overhead line. The transmission voltage is 500 kV and the maximum transmission power is 1,500 megawatts. The project was built by ABB.
NorNed is a 580-kilometre (360 mi) long high-voltage direct current submarine power cable between Feda in Norway and the seaport of Eemshaven in the Netherlands, which interconnects both countries' electrical grids. It was once the longest submarine power cable in the world. Budgeted at €550 million, and completed at a cost of €600m, the NorNed cable is a bipolar HVDC link with a voltage of ±450 kV and a capacity of 700 MW. NorNed is a joint project of the Norwegian transmission system operator Statnett and its Dutch counterpart TenneT. The cable system itself and the two converter stations were produced by ABB.
A submarine power cable is a transmission cable for carrying electric power below the surface of the water. These are called "submarine" because they usually carry electric power beneath salt water but it is also possible to use submarine power cables beneath fresh water. Examples of the latter exist that connect the mainland with large islands in the St. Lawrence River.
TenneT is a transmission system operator in the Netherlands and in a large part of Germany.
BARD Offshore 1 is a 400 megawatt (MW) North Sea offshore wind farm with 80 BARD 5.0 turbines. Since the owner could not buy such 5MW offshore wind turbines in sufficient numbers in 2006, Dr. Bekker set up its own production of turbines. This should serve as the legacy for his children. The systems were developed by aerodyn Energiesysteme GmbH. A plant for rotor blades and nacelle assembly was built in Emden and a plant for the offshore foundations in Cuxhaven. Two turbine prototypes were set up at the Rysumer Nacken in 2007, and another prototype in Hooksiel in 2008. Construction was finished in July 2013 and the wind farm was officially inaugurated in August 2013. The wind farm is located 100 kilometres (60 mi) northwest of the isle Borkum in 40-metre (130 ft) deep water.
HVDC BorWin1 is the first HVDC facility in the world to be built for importing power from an offshore wind park to shore, and the first to use voltage source converters (VSC) in Germany. It connects the offshore wind park BARD Offshore 1 and other offshore wind farms in Germany near Borkum to the European power grid. The facility was built by ABB and has a capacity of 400 MW at a bipolar voltage of ±150 kV. HVDC BorWin1, which leads from BorWin Alpha Offshore Platform to Diele substation, consists of a 75 kilometres (47 mi) of underground and 125 kilometres (78 mi) of submarine cable.
BritNed is a 1,000 MW high-voltage direct-current (HVDC) submarine power cable between the Isle of Grain in Kent, the United Kingdom; and Maasvlakte in Rotterdam, the Netherlands.
The North Sea Link is a 1,400 MW high-voltage direct current submarine power cable between Norway and the United Kingdom.
HVDC HelWin1 is a high voltage direct current (HVDC) link built to transmit Offshore wind power to the power grid of the German mainland. The project differs from most HVDC systems in that one of the two converter stations is built on a platform in the sea. Voltage-Sourced Converters are used and the total cable length is 130 km. The project was completed and handed over to its owner, TenneT, in February 2015.
An HVDC converter converts electric power from high voltage alternating current (AC) to high-voltage direct current (HVDC), or vice versa. HVDC is used as an alternative to AC for transmitting electrical energy over long distances or between AC power systems of different frequencies. HVDC converters capable of converting up to two gigawatts (GW) and with voltage ratings of up to 900 kilovolts (kV) have been built, and even higher ratings are technically feasible. A complete converter station may contain several such converters in series and/or parallel to achieve total system DC voltage ratings of up to 1,100 kV.
HVDC BorWin2 is a high voltage direct current (HVDC) link built to transmit offshore wind power to the power grid of the German mainland. The project differs from most HVDC systems in that one of the two converter stations 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/ Prysmian consortium and handed over to its owner, TenneT, in January 2015, becoming the first such project to be completed.
HVDC HelWin2 is a high voltage direct current (HVDC) link built to transmit offshore wind power to the power grid of the German mainland. The project differs from most HVDC systems in that one of the two converter stations is built on a platform in the sea. Voltage-Sourced Converters with DC ratings of 690 MW, ±320 kV are used and the total cable length is 130 km. The project was built by the Siemens/Prysmian consortium with the offshore platform built by Heerema in Zwijndrecht, Netherlands. The topside measures 98 m x 42 m x 28 m and weighs 10200 tonnes. The project was handed over to its owner, TenneT, in June 2015, the fourth such project to be completed in 2015.
HVDC SylWin1 is a high voltage direct current (HVDC) link under construction to transmit offshore wind power to the power grid of the German mainland. The project differs from most HVDC systems in that one of the two converter stations is built on a platform in the sea. Voltage-Sourced Converters with DC ratings of 864 MW, ±320 kV are used and the total cable length is 205 km. The project is similar to the HVDC BorWin2 project but has slightly higher power and voltage ratings. It is being built by the Siemens/ Prysmian consortium and was handed over to its owner, TenneT, in April 2015.
HVDC DolWin2 is a high voltage direct current (HVDC) link to transmit offshore wind power to the power grid of the German mainland. The project differs from most HVDC systems in that one of the two converter stations is built on a platform in the sea. Voltage-Sourced Converters with DC ratings of 900 MW, ±320 kV are used and the total cable length is 135 km. The project is similar to the HVDC DolWin1 project but has a slightly higher power rating and uses a different design of offshore platform. The platform was designed by Norwegian company Aibel and built by Drydocks World in Dubai and transported to Europe in the summer of 2014 to be fitted out at the Aibel yard in Haugesund in Norway. The platform, which is of a floating, self-installing design not previously used in an HVDC project, sailed out from Haugesund on 1 August 2015 and was installed in the North Sea ten days later.
HVDC DolWin3 is a high voltage direct current (HVDC) link to transmit Offshore wind power to the power grid of the German mainland. The project differs from most HVDC systems in that one of the two converter stations is built on a platform in the sea. Voltage-Sourced Converters with DC ratings of 900 MW, ±320 kV are used and the total cable length is 160 km.
HVDC BorWin3 is a high voltage direct current (HVDC) link under construction to transmit offshore wind power to the power grid of the German mainland. The project differs from most HVDC systems in that one of the two converter stations is built on a platform in the sea. Voltage-Sourced Converters with DC ratings of 900 MW, ±320 kV are used and the total cable length is 160 km. The project is the most recent of the German offshore HVDC projects to be awarded. It is being built by the Siemens/ Petrofac consortium with the offshore platform contract awarded to Drydocks World in Dubai. The project is expected to be handed over to its owner, TenneT, in 2019. The project started power transmission in August 2019. TenneT took control of operations in February 2020.
Veja Mate is a German 402 MW offshore wind farm in the German Bight of the North Sea about 95 km northwest of Borkum. The wind farm consists of 67 Siemens Wind Power SWT-6.0-154 turbines, each with a 6 MW capacity.
