innogy commits to third wind farm offshore Germany
innogy SE has taken the final investment decision for the construction of the 342-MW Kaskasi offshore wind farm in the German North Sea.
Located about 35 km (22 miles) north of the island of Heligoland, Kaskasi will be the company’s third wind farm offshore Germany.
The company has signed contracts totalling about €500 million (US$540 million) for the wind turbines and foundations, the offshore transformer substation, and the cabling.
Siemens Gamesa Renewable Energy SA will supply 38 SG 8.0-167 DD Flex offshore wind turbines. Each turbine will have a capacity of about 9 MW, a rotor diameter of 167 metres (548 feet), and a total height of 191 metres (627 feet).
The wind turbines as well as the offshore transformer substation will be installed on monopile foundations built by Bladt Industries A/S.
Seaway 7 is expected to start installation of the foundations using a new method in 3Q 2021 in water depths of 18 to 25 metres (59 to 82 feet).
The “vibro pile driving” is said to be an efficient alternative to the conventional method of hammering monopiles into the seabed. An innogy-led research project has shown that this installation method could deliver reduced installation times and noise emissions during construction.
Kaskasi will be the first wind farm in the world using the vibro driving technique to install all monopile foundations to target penetration.
The wind turbines will be connected with the Kaskasi substation via 33kV aluminium subsea cables, manufactured by Twentsche Kabel Fabriek, with different cross sections. Seaway 7 will install the 52 km (32 miles) of cables.
The wind farm is expected to start operations in summer 2022. The final date will be set in coordination with the offshore grid operator TenneT.
The Kaskasi offshore wind farm is to be connected to the same grid connection cluster as innogy’s nearby Nordsee Ost wind farm. The HelWin2 converter platform required for connection to the grid has been operational for several years.
Synergies with the Nordsee Ost wind farm will be used regarding operations and maintenance work, the company said. For example, the Kaskasi wind farm will be operated from the company’s existing service and operations station on Heligoland.
Source: Offshore Magazine