Gallery: Vattenfall's Yttre Stengrund decommissioned

SWEDEN: Vattenfall has decided to dismantle the 10MW Yttre Stengrund, its first Swedish offshore wind project, after 13 years of operation.

by David Weston 19 September 2014

  • Vattenfall has decided to decommision the 10MW Yttre Stengrund project after just 13 years of operation

    Vattenfall has decided to decommision the 10MW Yttre Stengrund project after just 13 years of operation

  • The Swedish utility said it would be too expensive to repair or replace the turbines

    The Swedish utility said it would be too expensive to repair or replace the turbines

  • The turbines will be dismantled and sold or recycled as scrap

    The turbines will be dismantled and sold or recycled as scrap

  • The project used 5 NEG Micon 2MW turbines - only 50 were ever made

    The project used 5 NEG Micon 2MW turbines - only 50 were ever made

  • The seabed will be returned to its original state, Vattenfall said

    The seabed will be returned to its original state, Vattenfall said

  • In 2002, one turbine needed to be replaced after a fire

    In 2002, one turbine needed to be replaced after a fire

  • The fire was caused by loose connections between the transformer and power cables

    The fire was caused by loose connections between the transformer and power cables

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Pictures taken from Windpower Monthly archive showing the project under construction and in operation.

Vattenfall made the decision to decommission the project due to the high cost of replacing turbines and cables.

Yttre Stengrund used five 2MW NEG Micon turbines when it was commissioned in 2001. Vattenfall said only one of the turbines is currently operational.

Only 50 of the turbines were ever made so replacement parts are no longer available.

The Swedish utility have also decided against installing new turbines as the project's export cable would need replacing if it was to continue operating. Decommissioning has been deemed the most economical option.

"We have chosen to decommission this wind farm prematurely and restore the seabed and ground installations in an ecologically correct way," said Torbjorn Walhborg, head of Vattenfall's Nordic unit.

The company said decommissioning will take approximately one month and could start next summer, weather dependent.

The turbines, towers, blades and cables will be dismantled and sold or recycled. The monopile foundations are likely to be cut down to the seabed, which will be restored to its original condition.

According to WPO Intelligence, Vattenfall acquired the project from Dong Energy in 2006.

In 2002, one of the NEG Micon turbines had to be replaced following a fire caused by loose connections between the transformer's connection bars and the power cables from the generator circuit breaker.