It requires something exceptional and extraordinary whenan offshore wind farm is dismantled for the first timein world history. WhenSwedish utility Vattenfallshortly before theturn of the year was facing the taskof dismantling Yttre Stengrund’s five offshore wind turbines in Kalmar Sound, special expertise was required.

The Swedish marine contracting companySvensk Sjöentreprenad ABwaschosen for the taskof appointingthe most competentsubcontractors for the job.They chose a joint collaboration between the Danish companies BMSKrangårdenA/SandConnectedWindServices, an independent service provider situated in Balle, Denmark, with business units in Sweden and Germany.

BMS Krangårdensuppliedthe requiredcrane capacity inconnection with the dismantlingand ConnectedWindServiceswas hired toprovide both the necessary equipmentand the highly specializedwind turbinetechnicians for the actualdismantlingof the 55meters high wind turbines

Knowhow and expertise

- For us it was100 percent obvious to contact ConnectedWindServices.Wehave worked closely withthemfor several years; theyare truly professionalsand weknew they coulddo the job, saysOleBerthelsen, who is Department Supervisor, CranesatBMSKrangården.

He stresses that ConnectedWindServiceswas chosenfor the taskbased onseveral specificreasons.

- As one of themarket leaders within serviceand refurbishment ofwind turbines, Connected Wind Services has the speciallifting gearand other equipmentrequired forsucha project. Furthermore their competent and highly educated employees possess both the required know-how andexpertise in this field. It was also an important factor thatConnectedWindServices is backed by a large,stable organization.

Pioneers within offshore

Project manager in Connected Wind Services, Mikkel Kærgaard, views the project as the company's litmus test within offshore wind turbines.

- The dismantling of Yttre Stengrund was a pioneer task for all of us who were involved, and that is why it was very important that it went well. The fact that we exceeded expectations was due to thorough preparations in combination with having very skilled employees, says Mikkel Kærgaard.

Connected Wind Services had a total of eight men assigned to the project for a period of one month. Thorough scheduling plus factored in challenging weather conditions which can occur especially at that time of the year meant that the time table was fully kept.

- We can thank our competent technicians for the short dismantling time which helped minimize delays due to bad weather conditions. As a team they have many years of experience in the wind power industry, and this is one of our most important strengths, says Mikkel Kærgaard.

He is pleased that the dismantling of Yttre Stengrund has proven that Connected Wind Services has the strength and expertise to solve very complex service projects, also when it involves offshore wind turbines.

Positivity and flexibility

For the project's main contractorSSE it was an important factor that ConnectedWindServicesisa highly skilledplayer in the market and has a uniqueknowledge of wind farm dismantling.

- Connected WindServicesdelivered a compelling description of methods and riskassessments, which both SSE and Vattenfall easily approved, saysJohanHolmberg, who is responsible forquality, environment and health&safety atMarConGroupAB, to which SSEbelongs.

At the same time he applauds the Connected Wind Services crew fortheir positive attitudeandflexibility insolvingthe variedtasks that such a project contains.

- Connected Wind Serviceshasstronglycontributed tothe project's success and to the customer’s overall satisfaction, saysJohanHolmberg.

Structured teamwork

Project manager Maria Hassel from Vattenfall also applauds the efforts of Connected Wind Services.

- We think they succeeded with flying colours and in perfect cooperation with all parties involved. The communication with Connected Wind Services has been really good throughout the two months the project lasted, says Maria Hassel.

She describes the Connected Wind Services technicians and their way of working as structured, calm and methodical and with a high degree of awareness, especially when it comes to both safety procedures and teamwork.

- In our line of business you can easily become stressed, because you have to hurry, and then tend to forget all about both structure and security. But this definitely did not happen to the people from Connected Wind Services, says Maria Hassel.

The decision to dismantle Yttre Stengrund was based on both technical and financial reasons. The wind turbines, of which only one was still in operation, were an early model which is no longer in production. Therefore it would be difficult to get hold of spare parts and costly to refurbish the generators, gearboxes and other main components.

FACTS ABOUT CONNECTED WIND SERVICES

• Connected Wind Services is one of the leading independent service providers in Europe

• CWS has a solid local presence deeply rooted in the European wind industry

• A strong service network with 45+ service teams

• CWS has more than 1850+ wind turbines in service

• 25+ years of experience and Europe’s first Independent Service Provider

FACTS ABOUT YTTRE STENGRUND

• The wind farm’s five wind turbines in Kalmar Sound had been in operation since 2001.

• Since 2006, Yttre Stengrund has been owned by Vattenfall.
  
  

  • The five NEG-Micon wind turbines were produced in Denmark and had a total capacity of
    10 MW.

  • Yttre Stengrund is the first offshore wind farm in the world to be decommissioned.

  • The decommission project was started in November and was finished in January.

  • The project was completed with Swedish Svensk Sjöentreprenad AB as main contractor.

  • The Danish crane company BMS Krangården A/ S supplied the crane capacity and was in charge of dismantling of concrete foundations. Connected Wind Services A/S was responsible for supplying both lifting equipment and other specialized equipment and decommissioning the rotors, nacelles and the five wind turbine towers, each consisting of two sections.
    
    Källa: Connected Wind Services