The company claims that it has chosen HVDC transmission cable technology over High Voltage Alternating Current (HVAC) technology as the former technology offers cost competitiveness due to fewer losses of transmitted electricity.

According to the company, the technology requires fewer cables connecting the wind farms to the grid and lower costs on and offshore substations and associated equipment.

Besides, the company stated that HVDC will have less of an impact on the environment and local people where onshore infrastructure is located.

Vattenfall said that it will form partnerships with HVDC cable and components manufacturers as well as platform manufacturers and civil construction companies to realise this project.

Vattenfall’s Business Area Wind Head Gunnar Groebler said: “Vattenfall wants to be a leader in maturing HVDC technology to connect its large-scale, far offshore wind farms – like Norfolk Vanguard and Norfolk Boreas – to national grids.

“In taking that lead, we will work with HVDC technology suppliers to deliver cost competitiveness for big offshore wind farm projects. Importantly, it also means that our decision to deploy HVDC for projects like Norfolk Vanguard and Norfolk Boreas is kinder to the environment and local people.”

Vattenfall’s Norfolk Vanguard is a 1.8GW offshore wind farm that will be located about 47km from the shore. It is expected to have turbines ranging between 90 and 257. The company expects to receive a consent decision from the UK Government for the wind farm at the end of 2019. 

Norfolk Boreas is also a 1.8GW offshore wind farm, which will be located more than 73km from the Norfolk Coast. Together these two offshore wind farms will produce 3.6GW of clean energy, which could satisfy the electricity demand for 2.5 million UK homes.

Image: Vattenfall choses HVDC for Norfolk twin offshore wind farms in the UK. Photo: Courtesy of sandi baker/