Vattenfall Connects Ormonde Offshore Wind Farm to National Grid (UK)

Vattenfall, currently installing a thirty-turbine wind farm off Barrow-in-Furness, finished three months of cable engineering works yesterday by completing the connection from the Ormonde Offshore Wind Farm to the National Grid.

The 42km export cable, which will take power from the wind farm to the mainland National Grid was simultaneously laid and buried in one uninterrupted operation from the shore to the offshore substation by Visser Smit. Vattenfall believes this is a UK first for a cable of that length and size.

With 8 of 30 turbines now deployed at the energy company’s pioneering offshore wind farm, the completion of export cable laying and connection works from the offshore substation to the Heysham onshore substation means that the generation of first power is only months away. Cable-laying between turbines and to the offshore substation continues.

Once the cables linking wind turbines to the substations are laid, engineers will work to enable the first turbines to receive power from the National Grid in a process known as ‘energisation’. Energisation allows engineers to test internal systems in the wind turbines before being able to safely generate first power and export to the Grid.

Project Manager Matthew Green said: “Vattenfall’s Ormonde Offshore Wind Farm is on schedule to deliver power to the grid later this year and the completion of the 42km export cable is a crucial landmark for the scheme because without it we could never deliver green power to people’s homes.

“The export cable was installed intact, without any joints and laid from shore to substation in one uninterrupted operation. This is probably a UK first for an export cable of this length and size connecting from an offshore wind farm and I think it demonstrates the expertise of the skilled engineers we have working on this project.”

He concluded: “As we continue to deploy wind turbines on site we will carry on with laying cables between the turbines and the offshore substation.”

The massive 42km long export cable, made of copper and heavily armoured with steel wires and polyethylene to protect the copper, weighs 3,500 tons. This weight is the same as eight fully loaded jumbo jets. The protected copper will transmit electricity from the 30-turbine wind farm to the mainland to meet the equivalent electricity demand of over 100,000 homes annually. Also encased in the cable are 48 optical fibres transmitting signals to control the wind farm.

The Ormonde Offshore Wind Farm is currently being built in the Irish Sea, 10km off Barrow-In-Furness. On completion the wind farm will comprise 30 REpower 5M wind turbines with the capacity of 150 megawatts (MW) and expected to produce around 500 gigawatt hours of electricity every year. This is sufficient to supply the equivalent electricity demand of more than 100,000 UK homes per year with clean power. The turbines will cover an area of 8.7km2 and construction commenced in May 2010 with first turbines deployed in March 2011.



Source: vattenfall, April 26, 2011;