30 MW Offshore Wind Turbines Being Considered for New Project in Sweden

Wind Farm Update

June 22, 2023, by Adrijana Buljan

Freja Offshore, a joint venture between Hexicon and Mainstream Renewable Power, has submitted an application for an offshore wind farm in Sweden that could have an installed capacity of between 2 GW and 2.5 GW and, according to the project’s consultation document, could feature wind turbines of up to 30 MW per unit.

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Single Wind Turbine Output Planned to Be Between 15 MW and 30 MW
Cirrus Project Could Combine Floating and Fixed-Bottom Offshore Wind

The offshore wind farm, named Cirrus, is proposed to be built in the Baltic Sea, off the south coast of Sweden, and its location was selected based on energy demands and with the expected substantial surge in electricity demand in Sweden, specifically in the southern region, in mind, according to the developers.

With the potential to deliver 10 TWh annually, Cirrus can provide renewable energy to over 2 million households per year, Freja Offshore says.

“We are excited about the immense potential the Cirrus project holds in terms of providing affordable electricity, generating job opportunities in the region, and in advancing our business objectives in our domestic market”, said Marcus Thor, CEO of Hexicon.

Single Wind Turbine Output Planned to Be Between 15 MW and 30 MW

In the Cirrus consultation document, Freja Offshore writes that the project would have between 85 and 133 wind turbines, with the site that has been chosen for the project able to accommodate a maximum of 133 wind turbines.

The joint venture then goes on to detail that the power output per single unit could be as much as 30 MW which, according to the document, the joint venture expects to be available by 2030.

The 30 MW wind turbines are said to have a maximum height of 370 metres and a rotor diameter of 340 metres.

In the case that the project would use these next-generation turbines, Cirrus would comprise 85 of them and, if wind turbines with a smaller rotor diameter and output are used, the maximum number of wind turbines would be higher, which would go up to 133 if 15 MW units would be installed.

The wind turbines in the future will probably be taller, the rotor diameter larger and the turbines more powerful, the joint venture says in the consultation document, and compares the largest wind turbines launched in 2011, which have a rotor diameter of 164 metres and an installed capacity of 8 MW, with those launched 10 years later, featuring a rotor diameter of 236 metres and an output of 15 MW.

“As a result of this development, it is expected that 30 MW turbines with a rotor diameter of 330 metres will be launched between 2025 and 2030”.

Cirrus Project Could Combine Floating and Fixed-Bottom Offshore Wind

The Hexicon-Mainstream Renewable Power partnership also plans to potentially install a combination of fixed-bottom and floating wind turbines.

“Cirrus is planned to be an offshore wind farm with bottom-fixed turbines, but Freja Offshore will also investigate the potential use of floating wind turbines for the deepest sections. The offshore wind farm will however still be beyond the horizon and just barely visible during clear weather conditions as it will be situated 50 kilometers off the coastline”, the joint venture stated in a press release on 22 June.

According to the consultation document, the floating option could not only be chosen for some of the wind turbines but is also being considered as one of the possibilities for an offshore substation.

Freja Offshore also noted that the wind farm site had been “meticulously designed” to minimise any disturbances and seamlessly coexist with other vital societal concerns, particularly addressing the needs of other users of the sea such as the Swedish Armed Forces.

Cirrus offshore wind project location; Image: Cirrus consultation document; Freja Offshore

The project site is located in the southern Baltic Sea, some 50 kilometres south of Karlskrona and 50 kilometres south of Öland, in Sweden’s exclusive economic zone.

The application, now submitted to the Swedish Ministry of Climate and Business, is related to the construction and operation of the Cirrus offshore wind farm in accordance with the Law on Sweden’s Economic Zone (SEZ) and the establishment of an internal cable network under the Continental Shelf Act.

The project’s proximity to Natura 2000 areas may mean that a special Natura 2000 assessment would be needed, so the joint venture also included an assessment for this permit in the consultation document, as well.

Cirrus is not the first project Hexicon and Mainstream Renewable Power plan to build in Sweden.

In April, the joint venture submitted a planning application under the Swedish Economic Zone Act (SEZ) for another, 2.5 GW offshore wind project. Located in the North Sea and named Mareld, this project is planned to comprise floating wind turbines.