Sheringham Shoal Offshore Wind Farm substation delivery by Wood Group PSNMatt WrenMarketing Coordinator, AVEVA20AVEVA World Magazine 2012|Issue 2One of the two 900-tonne Sheringham Shoal offshore wind farm substations designed by Wood Group PSN. Image courtesy of CHPV & Statkraft.Images above, from left to right: AVEVA PDMS model of one of the offshore substations; a substation under construction; the two substations being transported prior to installation. Images courtesy of Wood Group PSN.
Surrounded as it is by sea, the UK has the largest offshore wind energy resource in the world, estimated to be more than a third of the total European potential. This is equivalent to three times the nation's annual electricity consumption.On 2nd of August 2011, the first turbine installed and commissioned at the Sheringham Shoal Offshore Wind Farm started producing electricity for the UK grid.Owned and operated by Scira Offshore Energy Limited, a joint venture between Statoil and Statkraft, the 317 MW wind farm will comprise 88 wind turbines and generate around 1.1 TWh per annum of green energy for almost 220,000 homes. Compared to fossil fuels that is a reduction of around 500,000 tonnes of CO² emissions every year.In 2009, Wood Group PSN, formerly Wood Group Engineering (North Sea) Ltd, secured a contract for the design and project management of two 900-tonne offshore substations from AREVA T&D UK Ltd, with the design undertaken in AVEVA PDMS.As long-standing users of AVEVA PDMS, since the company's first purchase in 1999, Wood Group PSN provided its team of engineers with a comprehensive and detailed catalogue of predefined structural joint and multi-discipline support templates. These standardisations, which all conform to British Standards, included the development of design rules and line styles that would consistently deliver the level of detail and information to accompany each joint and support.Incorporating the structural and draft enhancements into the design of the substations allowed the engineering team to ensure that, when constructed, the weight of the substations was within 10% and the centre of gravity within half a metre, of the original design. This level of accuracy was a key requirement for the project because the substation modules each stand on a single monopod structure, designed and installed at sea by a separate engineering company. The challenge from the start for Wood Group PSN was designing a module that could be shipped out to sea, lifted by a sea crane and placed onto the installed monopod structures. These project requirements led the team to use the intelligence within the PDMS model to create accurate fabrication and installation drawings. Colin Bannerman, Head of Structural Design for Wood Group PSN said, 'The complexity of some of the structural modifications we have undertaken on both existing plants and new-build projects, teamed with the requirement for changes along the way, have made it almost impossible to undertake design using 2D drafting alone. This led us to embark on a project to generate and deliver information using PDMS. The results of this project and particularly the ease with which we can now produce high quality fabrication and installation drawings have been staggering.'Neil Hebden, Global Head of Technical Applications for Wood Group PSN added, 'Providing a full catalogue of compound interlinked joints and templates allows our design teams to focus on the, often very complex, engineering task in hand. Standardisation of the software also means that we can move engineers between projects with minimum disruption, thus providing our clients with the full benefit of our engineering expertise.' To ensure a successful delivery of the project, Wood Group PSN regularly met with AREVA during the design and construction phase of the substations, using both the AVEVA Review model and the live PDMS model to evaluate the current status of the design and discuss challenges and options as they arose.'Man-hours and project costs are huge and grow exponentially with the size of the project,' Hebden continued. 'We focus on creating cost savings for our customers, but in projects like this we are faced with the age-old question of how to evaluate the impact and cost of change. With much of our work constructed onshore and shipped offshore, there is no margin for error.'About Wood GroupWood Group is an international energy services company. The Group has three businesses - Engineering, Wood Group PSN and Wood Group GTS - providing a range of engineering, production support, maintenance management and industrial gas turbine overhaul and repair services to the oil & gas and power generation industries worldwide. Wood Group PSN is the leading global provider of pre-operations, hook-up and commissioning, operations and maintenance, engineering, construction, project management, training, and decommissioning services, primarily to the energy industry. For more information, visit www.woodgroup.comor www.woodgroup-psn.com.Project Update Currently nearing completion and due to be fully operational by late summer 2012, the 35km² wind farm is located between 17 and 23km off the coast of North Norfolk in the UK. Scira Offshore Energy has a 50 year lease on the wind farm site.As well as the 88 turbines, which are positioned less than a kilometre apart and supported by foundations secured to the seabed, and the two offshore substations, the wind farm comprises two submarine export cables of about 22km each which transport the power onshore. A 21km cable then takes the power inland to the new Salle substation, where it is fed into the National Grid.www.aveva.com/45yearsAVEVA World Magazine 2012|Issue 221