WORKING AT HEIGHTS - Wind Energy Network

metmasts featureMetmastsa trial run for offshore windturbine foundationsMeteorological masts are a necessarytool to assess the wind resource andthe future profitability of wind farms.But they also can be used to de-riskthe future development in many otherways.Factors to considerOne of the major risks of future large-scalewind farms on the UKCS is the cost offoundations for offshore wind turbines andtheir installation. There are several factorsat play.Kirill Glukhovskoy – Director, Corporate& Business Development• which turbines are going to be used?– larger turbines will inevitably requireheavier and more robust foundations• deeper on average waters will requiretaller and larger foundations• further from shore locations will puta strain on logistics of deliveringthese heavier and larger structures tothe installation site and their installation• just the sheer scale of thesedevelopments, many of which will startconstruction almost simultaneously, isa challenge by itselfPreparation ensures successSome of the offshore wind developershave realised that the success isin preparation and have used metmasts as a test for offshore WTGfoundations and installation methods.It benefits the developer, who isable to evaluate the technologicaladvantages and disadvantages of aparticular foundation type, the costsof fabrication, transportation andinstallation.It also helps companies withinnovative approaches to foundationsto gain the track record, receivevery useful feedback and test installationmethods. However, there is still asignificant difference between a foundationfor a met mast and a foundation for a windturbine.Bespoke design criteriaA met mast foundation can be designedwith a particular turbine in mind. This willprovide even more certainty about theconstruction methods and costs of futurefoundations and their installation in a lowerrisk environment. It will also simplify futurecertification work and acceptance of suchfoundations by bankers and insurancecompanies.In the situation when there are no currentlyavailable demonstration sites for deepwater foundations in the UK, met mastprojects are increasingly important astesting grounds.Reducing riskAs an outcome, met mast projectsbecome a versatile tool for reducing therisk of future offshore wind developmentsat a marginal cost rather than just anexpenditure to be scrapped in the future.Aquind OGNwww.ogn-group.comClick to view more infoOffshore metmast instrumentationTraditionally site conditions aremeasured using a meteorological mast,which hold instruments measuring windspeed, wind direction and atmosphericconditions at various heights.The primary function of any met mastproject is to collect high quality dataand performing this work offshore offersexciting new challenges and opportunities.A challengeLimited access windows at sea meanthat it is essential that met masts offshoreare stand-alone solutions offering remoteaccess and control options to ensuregood data availability and minimisingcostly site intervention visits. Achieving thiswhile still producing high quality data is achallenge which requires careful designof the interfaces between measurementinstrumentation, navigation equipment,communication systems, and power delivery.GuidelinesSeveral guidelines are in place to helpdesigners achieve complete, reliablesolutions. The IEC 61400:12:1, IEARecommended Practices on WindSpeed Measurement and the Use ofCup Anemometry, and MEASNET cupanemometer calibration all ensure that metmasts provide bankable wind speed data.The IALA Marking of Offshore Man-MadeStructures and Civil Aviation guidelines are allin place to ensure that offshore met mastsdo not present a hazard to passing ships orairplanes, and to give minimum operationalguidelines in terms of power autonomy inthe event of a power or instrument failure.MaintenanceMaintenance requirements for metmasts must also be considered whenspecifying systems. Finding equipmentwhich can be attended to without the useof specialist tools or lifting equipment isof vital importance offshore. Safety mustbe guaranteed offshore, so maintenanceschedules must be specified to avoidpotentially dangerous situations.Making sure that maintenance schedulesare as clear and concise as possiblewill also ensure a good relationship withoffshore contractors!104www.windenergynetwork.co.uk