North West

Walney wind workers forge ahead

Remarkable progress is being made on DONG Energy’s Walney Offshore Wind Farm in Cumbria. During 2010 to 2011, Walney (UK) Offshore Wind Farms Ltd. have been constructing phases I and II of the Walney Offshore Wind Farm, which is located approximately 15km off Walney Island, Cumbria, in the East Irish Sea.

Each of the two phases consists of 51 turbines with a total capacity of 367.2MW. The development includes: foundations, turbines, export and array cables, offshore substations and onshore connection to the power grid.

Walney Offshore Wind farm is located away from the coast, which results in relatively low visual impacts. The turbines will be located approximately 15km from the coastline of Walney Island in a north west to south-easterly direction covering an area of approximately 73km2.

In the first phase, the wind farm consists of 51 turbines supplied by Siemens Wind Power – each with a capacity of 3.6MW – and in total the annual net energy for Walney I is estimated to be approximately 663GWh, which will make the wind farm one of the biggest of its kind in the world.

The Irish Sea is characterised by high tides, waves and windy weather. The difference between high tide and low tide is approximately 8 metres. The wind speed is estimated to be an average of 9.3 m/s at 80m. The construction of the foundations and installation of the wind turbines involves a number of work boats, crane barges and support vessels sourced for their ability to work under challenging conditions.

The wind farm turbine array consists of a number of rows of wind turbines connected by cables to one substation, where the voltage is stepped up from 34 kV to 132 kV, before the export cables on the seabed carries the power to shore.

The offshore substation in Walney 1 is placed inside the area of the wind farm, and was placed on Tuesday 15 June 2010, as one gigantic 1,100-tonne lifting operation concluded that phase of the project.

Turbines are currently being installed for both phases.

The wind farm will contribute to handling the issue of climate change. With a power capacity of 370MW (phase 1 + 2), possibly increasing to 600MW, Walney Offshore Wind Farm will make a substantial contribution to British renewable energy production.

Towards the end of 2010, the 51 turbines comprising Walney 1 were completed. Weather conditions have been average for the area – a situation which has been planned for and which, from time to time, results in delays.

All offshore operations are fully dependant on the weather conditions and require thorough planning in order to utilise the weather windows suitable for installation activities. Wind and waves determine the progress in the installation. For wind turbine installation, the operational crane limit is typically a wind speed of 10 m/s, however, only about 8 m/s can be tolerated during installation of the blades.

DONG site manager Lars Alber told Premier Construction, “The first phase of the works went well and we are looking forward to completing the second phase with the same success”.

Systems Navigator demonstrate logistical solutions at Walney

 Netherlands based firm Systems Navigator provided a simulation model for the logistical processes involved in constructing the Walney offshore wind farm.

The construction process is complex: pillars or so-called monopiles are shipped into port, landed and then re-loaded onto transportation tugs to be towed to a specialist crane vessel to be placed in the sea. Hiring this second vessel is expensive, so time-efficiency is crucial.

Many different factors were in play to affect the construction of the wind farm – these included tide, wave and weather conditions. All of this information was combined by Systems Navigator to create a tool that could be used in the planning process to model and animate potential situations at all stages throughout the construction operation.

Having this technology also allows the construction firm to model the impact of decisions made throughout the process, before actually implementing those decisions in reality. This maximises the efficiency and safety of construction processes.

Systems Navigator was founded in 2003 by Rienk Bijlsma, who has sixteen years of experience in simulation modelling. Using simulation technology to model construction logistics is a recent innovation, and the company are the leading experts in the field, delivering services on projects throughout the world.

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Roma Publications

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