Ethical Investments
“Strict regulation is needed in this country for all building types and priority should be given to schools and hospitals”
The design was undertaken in tandem with a separate joint industry project established to overcome problems that have been reported on some monopile foundations. London Array Project Manager, Soren Thorbjorn Larsen said, “The construction and design (has been) a major technical and engineering challenge, and we have paid close attention from the very beginning to ensuring that we got the design absolutely right. On schedule 101 foundations have been installed offshore by the three installation vessels working onsite – Sea Worker, MPI Adventure and HLV Svanen. Adventure is continuing to install foundations, Sea Worker, after completing foundation installation, has now started to install wind turbines. Sea Worker will be joined by MPI Discovery, who will also install wind turbines at London Array, shortly. Array cable installation started towards the end of last summer and the first export cable, which will connect the offshore substations to the new onshore substation at Cleve Hill, was installed towards the end of 2011. The Stemat Spirit, the cable laying vessel that is installing the export cables, is on station, waiting to start the installation of the second export cable. At the end of January, the first of 175 turbines was installed. Meanwhile, Siemens has been manufacturing turbines for the project since last May, with the intention that some of them will be brought to the site directly from Esbjerg Port in Denmark while the rest are brought by barge to Harwich then transported to the site. Avoiding pitfalls The Array is among the first in the world to use a conical joint at the top of its monopiles to prevent transition piece slippage.
www.buildgreen.ae
“As well as dealing with new industry issues, such as how to safeguard against foundation grouting and slippage problems, we have had to take into account the wide variation in water depths and moveable seabed across the wind farm site.” The new foundation design features a gently sloping cone at the top of the monopile which then sits inside an inverted cone at the bottom of the transition piece. A layer of grout lies between the two surfaces. This design has reportedly met with the highest industry standards, and could pioneer a new best practice for offshore wind.
Environmental Impact – A potential model for the Middle East’s construction projects Massive construction always takes a toll on the natural landscape of the site, which is why London Array has been developing strategies to mitigate any negative impact the 100 square metre site may cause. Their aim is to help the UK meet the its environmental and renewable energy targets, such as reducing CO2 emissions by 34 per cent by 2020 and generating 15 per cent of all energy from renewable sources by 2015. Mathematically, this suggests that the completed and fully functional wind farm will be able to reduce carbon emissions by 1.4 million tonnes each year. Phase One alone will enable 925,000 tonnes of CO2 to be offset each year. With a total capacity of up to 1,000 megawatts, the wind farm will be able to generate enough electricity for up to 750,000 homes, roughly one-fourth of residences in Greater London. Phase One’s capacity of 630MW is enough to power around 480,000 homes, or twothirds of all homes in Kent. Long-term environmental benefits aside, the project presently has been issuing notices to the local shipping and fishing industries to keep them informed of all their activities during construction. These notices include details on which parts of the Thames Estuary the construction will be at on a weekly basis as construction has moved offshore. Ecologically, the project has also taken steps to monitor and survey the site with advice from Natural England and CEFAS. Before construction, the surveys provide details on the ecological conditions of the site and the requirements that may need to be followed before, during and after construction. Sustainable construction has helped the project stick to its green ideals in most steps of its development.
March 2012
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