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Marine Renewable Energy – ICE Conference Delegate Pack – DHI


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ICE Conference.
Marine Renewable Energy – Meeting the Need.
University of Plymouth, Monday 1 October 2012.

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Marine Renewable Energy – ICE Conference Delegate Pack – DHI

  1. 1. CONFERENCE NEWSLETTERMarine Renewable Energy – Meeting the NeedUniversity of Plymouth, Monday 1 October 2012NEWS RESEARCHTeraWatt project – large scale interactive coupled 3D Radar @ Sea – prize winning poster at EWEA 2012 windmodelling for wave and tidal energy resource and energy conferenceenvironmental impact using MIKE by DHI software Wind power fluctuations strongly affect offshore wind farms. Weather radars offer a promising tool for the development of aScotland has substantial wave and tidal energy resources and is at the dedicated monitoring and short-term prediction system. Aforefront of the development of marine renewable technologies and collaborative research project between Vattenfall, DTU, DONG,ocean energy exploitation. Wave and tidal energy devices will soon be and ourselves was awarded a prize for originality and futuredeployed in arrays, with many sites being developed. It is therefore expectations at the EWEA 2012 event in Copenhagen. Theessential to understand how a number of multi-site developments research project suggests how the use of weather radar cancollectively impact on the physical and biological processes over a improve operations for offshore wind farms, giving earlywider region. Careful selection of array sites may enable the optimum warnings for shut-down during wind-burst conditions.exploitation of the resource while minimising any environmentalimpacts to an acceptable level. Please take a copy of the poster from our table.The TeraWatt project is a £1m project funded by the Engineering andPhysical Sciences Research Council through its Marine Challenge Fund.The project consortium has been established under the auspices of the CASE STORYMarine Alliance for Science and Technology for Scotland (MASTS) with Supporting tidal energy - metocean design conditions inscientists from the Universities of Heriot-Watt, Edinburgh, Highlands the Pentland Firthand Islands, Strathclyde, Swansea and Aberdeen, and Marine Scotland The Pentland Firth in Scotland is one of the most energeticScience (MSS). marine sites in Europe making it highly attractive for tidal energy projects. However, the site is also exposed to severe waveThe overarching objective of the research is to generate a suite of conditions, presenting a very challenging environment for suchmethodologies that can provide a better understanding of the impact of extraction on the resource. Approaches will also be developedthat can be employed to assess the physical and ecological The MeyGen tidal stream project plans to build a 398MW turbineconsequences of changes to the resource. The project objective will be array – generating electricity equivalent to that required tomet by investigating spatial changes in wave climate, physical power 400,000 homes – in the Inner Sound of the Pentland Firth.processes affecting sediments, the shoreline & seabed, and the impacts In order to ensure optimal design of the foundations and turbineon organisms living in the seabed, their distribution and the superstructure, MeyGen commissioned us to provide designsignificance of these for other ecological processes. criteria, fatigue, and operational MetOcean data at the site. The study observed severe wave-current interaction in the area.MIKE by DHI software has been chosen by the TeraWatt Consortium to This occurs when tidal currents are sufficiently strong to alter thesupport their research. Coupled MIKE 3 FMHD and MIKE 21 SW characteristics of the wave climate. In conditions where tidalmodels form the foundations of the adopted MIKE software platform. currents oppose the waves, extremely steep waves are produced.These core models will be augmented by MIKE 21 BW, MIKE 3 FMMT, We were able to simulate this process and capture waves ofMIKE 3 FMST, LITPACK, MIKE 3 FM ECO Lab & ABM Lab, EVA and similar steepness to those observed. Our results will be used byMIKE Animator in order to consider the specific responsibilities of each MeyGen to further optimise their turbine design and ensure thatpartner university. their structures are able to withstand the harshest conditions expected in their design lives. Moreover, turbine installation can be planned to maximise safety and minimise cost and downtime. Deployment of the first units is planned to commence in 2014. “...In a recent review by the UK Crown Estate, it was found that of all the bidders that have won rights to install tidal and wave arrays around the UK, more than 90% used the MIKE by DHI software.”
  2. 2. Marine Renewable Energy – Meeting the NeedUniversity of Plymouth, Monday 01 October 2012CASE STORY RESEARCHHelping Atlantis tune to the tides EPSRC project partner – optimal design of very large tidal stream farms for shallow estuarine applicationsTidal flows vary greatly with geography across the globe. Also,interaction between turbines in a prime location can impact the The project is a collaboration between SuperGen Marine, theintensity and direction of tidal flows themselves both locally and Exeter Centre for Water Resources (Non-SuperGen), Penn Stateregionally. University, Aquascientific Ltd. and ourselves. It is mentored by Garrad Hassan Partners. The primary goal is the introduction of aAs such, the success of sustainable, financial risk-reduced and cost- new hybrid optimisation approach which results in a multi-effective tidal power generation depends on the accurate knowledge of objective optimal design of the layout and power loadings oftidal energy flows at specific sites. In short, it is imperative to identify marine energy farms, subject to environmental impacts. Thethe best site within an area of interest, to make successful tidal power specific application focus involves tidal turbines suited togeneration a reality. With our global experience, state-of-the-art operating in shallow, medium flow estuaries but the techniquesoftware and dedicated Decision Support System (DSS), we helped our can be applied to all types of marine energy farms. Optimisation isclient – Atlantis Resources Corporation – to do just that. subject to minimising flood risk with further environmentalPlease take a copy of the full case story from our table. impacts, such as sediment transport-driven outcomes, being optionally incorporated as slow timescale effects. One aim of our participation in the project is to enable anRESEARCH improved and more accurate description of tidal stream energyPredicting scour in offshore wind farms – now a breeze with converters to be implemented in the MIKE 21 flow models.WiTuS Within the project, the University of Exeter will be using MIKE 21,Our research into long-term scour predictions has borne fruit in the with a damage assessment tool developed at the University, toform of a specialty tool - WiTuS. With WiTuS, it is now possible to assess the effects of tidal energy farms on flood risk.model long-term predictions on scouring around monopile typefoundations. Armed with such predictive information, you can optfor simpler and cheaper designs for your wind turbine, withoutcompromising on safety. Accordingly, you can plan the accurate NEWSmeasure of scour protection for your wind turbine foundation and MIKE by DHI software Release 2012save on investment costs in the process. We are pleased to advise that the new MIKE by DHI SoftwarePlease take a copy of the full case story from our table. Release 2012 will be available in October 2012, and will contain many improvements and new features of particular benefit to our marine users:CASE STORY Linux porting of simulation engines – The MIKE 21 and MIKE 3Metocean water forecast and monitoring around London simulation engines in the FM series are ported for execution onArray wind farm, UK Linux computers, thus allowing simulations on massive computerWe were commissioned to develop the complete MetOcean clusters (HPC).forecasting system—a prerequisite for efficient and safe planning Agent based modelling – A brand new module, called ABM Lab,and operations. The service comprised deployment, maintenance, is being launched with Release 2012. ABM Lab is used forand operation of three wave and current buoys and a tide gauge; all modelling the behaviour and fate of moving agents, typically fishequipped with iridium satellite communication for online data or other living organisms, in the water environment.transfer. By applying data assimilation, the online measurements Improved structures – Important improvements in the MIKE 21are used to feed hydrodynamic models which predict the wave and and MIKE 3 structure descriptions, including improvedcurrent conditions. Combined with meteorological models, this descriptions of tidal turbines.provides a complete five-day forecast system for wind, air Other improvements – New version of MIKE Animator, new ECOtemperature, sea temperature, visibility, lightning risk, cloud height, Lab editor, Mesh Generator engine improved to handle largerwater levels, wave heights and currents. data sets, global tide model improvements, and more…For more information, please visit: NEWS Environment Agency to launch new Central Modelling Platform with huge MIKE by DHI software installation The Environment Agency has developed a Central Modelling Platform (CMP) based upon a Virtual Desktop Infrastructure solution to support their regional and national modelling efforts. Once fully implemented the CMP will service up to 500 concurrent users nationwide and will host a range of modelling software applications including MIKE by DHI. The MIKE by DHI software installation on the CMP initially includes MIKE 11, MIKE October 2012 ©DHI FLOOD, MIKE 21, MIKE 3, MIKE SHE, ECO Lab, MIKE 21C, LITPACK, and MIKE Animator, covering a wide range of the water modelling needs of the Environment Agency. For more information, please contact Steve Flood on or visit our websites and
  3. 3. RENEWABLES at DHIMarine Renewable Energy – Meeting the NeedUniversity of Plymouth, Monday 1 October 2012MIKE by DHI Modelling Tools Specialist Consultancy In addition to, and in conjunction with, our TIDAL FLOWS WAVES renowned MIKE by DHI software, we offer specialist consultancy services to the marine renewables industry. Fulfilling a research based specialist advisor role, we are a ‘Consultant to the Consultants’. Planning and design phase  Survey and monitoring  Strategic marine spatial planning  Strategic environmental assessment  Feasibility studies  Environmental baseline investigations MIKE 21/3 FMHD  Environmental impact assessments  Habitat impact assessments MIKE 21 SW &  Metocean design data  Scour protection optimisation MIKE 21 BW  Hydrodynamic loads and motions  Applications for environmental licences ENVIRONMENT MIKE 21/3 FM Construction phase ECO Lab & ABM SEDIMENTS  Operational hydrographic water forecasting for construction and Lab MIKE 21/3 FMST, navigation  Optimisation of installation procedures FMMT & LITPACK  Environmental management and monitoring of marine construction Operational/maintenance phase  Hydrographic water forecasting  Decision support systems  Environmental monitoring October 2012 ©DHI ADVANCED TECHNOLOGIES Decommissioning phase  Operational hydrographic water forecasts for dismantling and navigation  Optimisation of removal procedures  Environmental management and monitoring of operations MIKE CUSTOMISED Please visit our stand to pick up a brochure
  4. 4. SOFTWARE SUMMARYMarine Renewable Energy – Meeting the NeedUniversity of Plymouth, Monday 1 October 2012MIKE 21 / 3 FM HDHydrodynamic modelling in two– and three–dimensionsThe Hydrodynamic Module included in MIKE 21 & MIKE 3 Flow Model FM simulates water level variations and unsteady flows in response to avariety of forcing functions in the marine environment including density variations, bathymetry and external forcings. It also provides thebasis for computations performed in many other modules. The choice between 2D and 3D model depends on a number of factors. Forexample, in shallow waters, wind and tidal current are often sufficient to keep the water column well-mixed, i.e. homogeneous in salinity andtemperature. In such cases a 2D model can be used. In water bodies with stratification, either by density or by species (ecology), a 3D modelshould be used. The modelling system is based on the numerical solution of the two-/three-dimensional incompressible Reynolds averaged Navier-Stokes equations subject to the assumptions of Boussinesq and of hydrostatic pressure. The model, therefore, consists of continuity, momentum, temperature, salinity and density equations and it is closed by a turbulent closure scheme. The density does not depend on the pressure, but only on the temperature and the salinity. For the 3D model, the free surface is taken into account using a sigma-coordinate transformation approach. The spatial discretisation of the primitive equations is performed using a cell-centred finite volume method. The spatial domain is discretised by subdivision of the continuum into non-overlapping elements/cells. In the horizontal plane an unstructured mesh is used while a structured mesh is used in the vertical domain of the 3D model. In the 2D model the elements can be triangles or quadrilateral elements. In the 3D model the elements can be prisms or bricks whose horizontal faces are triangles and quadrilateral elements, respectively.MIKE 21 SWSimulating offshore and nearshore wave fieldsMIKE 21 SW is a 3rd generation spectral wind-wave model that simulates the growth, decay and transformation of wind-generated waves andswell in offshore and coastal areas. It is used for a wide range of wave climates assessments in offshore and coastal areas, both hindcast andforecast mode, including design of offshore, coastal and port structures, where accurate assessment of wave loads is of utmost importance tothe safe and economic design of these structures.MIKE 21 SW solves the spectral wave action balance equation formulated ineither Cartesian or spherical coordinates. At each mesh point, the wave fieldis represented by a discrete two-dimensional wave action density spectrumusing either a fully spectral or directional decoupled parametric formulation.The discretisation of the governing equations in geographical and spectralspace is performed using cell-centred finite volume method. In geographicaldomain an unstructured mesh is used. The time integration is performedusing a fractional step approach where a multi-sequence explicit method isapplied for the propagation of wave action.The model includes the following physical phenomena; wave growth byaction of wind, non-linear wave-wave interaction, dissipation by white-capping, dissipation by wave breaking, dissipation due to bottom friction,refraction due to depth variations, and wave-current interaction.MIKE 21 SW is also used for the calculation of the sediment transport, which for a large part is determined by wave conditions and associatedwave-induced currents. The wave-induced current is generated by the gradients in radiation stresses that occur in the surf zone. MIKE 21 SWcan be used to calculate the wave conditions and associated radiation stresses. The long-shore currents and sediment transport is thencalculated using the flow and sediment transport models available in the MIKE 21 package.
  5. 5. Marine Renewable Energy – Meeting the NeedUniversity of Plymouth, Monday 01 October 2012ECO Lab & ABM LabAssessing impacts on the marine environment and its populationsMIKE 21/3 ECO Lab FM is a state-of-the-art numerical tool for 2D and 3D ecological modelling of ecosystems. The combination of a user-friendly interface, open access to the governing equations and the coupling of ECO Lab to the MIKE 21/3 FM flow models makes MIKE 21/3ECO Lab FM a powerful tool. MIKE 21/3 ECO Lab FM is typically applied in environmental water quality studies in coastal areas, estuaries, andlakes.MIKE 21/3 ECO Lab FM is capable of simulating the spatial distribution of state variable concentrations in a 2D or 3D domain based onprocesses such as advective transport, settling and biological, physical and chemical transformation processes. Variables are defined as either fixed state, meaning stationary, or advective state, meaning mobile. Differential equations are used to describe the processes applicable to each variable including transformation and settling. It is possible to describe state variables that are bound to the seabed, the water surface, the sediment, or can be found in the whole water column. ECO Lab gives easy access to the formulation of the biological, chemical and settling processes. The user has the option of viewing, modifying or creating the formulation of the processes and to introduce new state variables to simulate. It is therefore possible to create completely new model concepts containing the necessary causal relations to describe the specific phenomena in question. The ECO Lab model containing the formulation of the biological and chemical interaction between the state variables is saved in an ECO Lab template. A number of default templatesare supplied with the model including eutrophication, water quality and heavy metals. The ECO Lab template is independent of the horizontaldiscretization into a computational grid and can therefore be shared with the other DHI software models supporting ECO Lab.ABM Lab constitutes a unique environment for establishing Agent or Individual Based Models within the aquatic environment. Specifically, it ispossible to describe the behaviour of individual organisms within a population by considering both the behavioural characteristics (e.g. age,mass, relationship to other agents) of the individual organisms (e.g. fish), represented as Lagrangian variables in ABM Lab, and the influence ofenvironmental conditions (bathymetry, flow, water level, temperature, salinity and many other parameters; including water quality).LITPACKShoreline evolution and littoral processesLITPACK is a deterministic numerical modelling system which describes the major processes in the nearshore zone. The main sedimenttransport engine and boundary condition data are derived from the MIKE 21 / 3 modelling suite, ensuring a coherent approach to anyassessment. The individual modules of the LITPACK suite simulate different coastal processes, with the linking between modules beingperformed by an automatic control module. This allows rapid simulation of complex coastal problems without loss of detail in the individualmodules. The processes covered by the individual modules can bebroadly described as: non-cohesive sediment transport in waves and currents—the vertical sediment diffusion equation is solved on an intra-wave period grid to provide a detail description of non-cohesive sediment transport using a turbulent wave-current boundary layer model and considering suspended and bedload transport separately. longshore current and littoral drift—the model includes a description of propagation, shoaling and breaking of waves, calculation of the driving forces due to radiation stress gradients and momentum balance for the cross-shore and longshore directions leading to predictions of wave set-up and longshore current velocities. coastal evolution—the coastal response to gradients in the longshore sediment transport capacity is calculated by solving a continuity equation for the sediment in the littoral zone. The influence of both natural features and a wide variety of coastal structures are included. cross-shore profile development—the bottom sediment continuity equation is solved to determine the impact of a time-varying wave climate on the beach profile.Plus...Other models and tools to help you get the most out of our software MIKE 21 / 3 FM MT and ST are sediment transport models developed to allow simulation of mud and sand transport, respectively. Both models obtain their hydrodynamic data October 2012 ©DHI from the main Hydrodynamic Model and each one considers different aspects of sediment transport for cohesive and non-cohesive sediments. MIKE Animator allows the production of graphical representations of model results which add value to studies and provide material for easy communication with interested parties. Three-dimensional or slice plots can be exported, for example, as well as static and fly-through movies. And much, much more... For more information, please visit our stand or contact Steve Flood on Visit our websites and
  6. 6. WATER RESOURCES GROUNDWATER & POROUS MEDIAReshaping the scene of water resources FEFLOWRelease 2012 provides a range of significant new FEFLOW 6.1 sets a new standard in groundwaterdevelopments and features for the water resources modelling by providing the entire range of itssoftware products. functionality in one modern user interface. In addition to introducing a new GUI, FEFLOW 6.1Selected examples are: has several new features: MIKE HYDRO BASIN  Display of calibration targets and statistics The future GUI platform for DHI’s water resources  Selective mesh smoothing products, MIKE HYDRO, is introduced. Release 2012  Stereoscopic views and image/video export includes the River Basin Water Management module (WM) used for IWRM, water resources assessment,  Improved multiscreen support water allocation, reservoir operation and other  Text display in view windows types of analysis, planning and management model  Improved isoline display and labelling studies  Improved path line visualisation  Expression based user variables MIKE FLOOD AD  Improved map data handling Advection-dispersion modelling is now available  Selection from 3D maps in MIKE FLOOD. With this release, fully dynamic, coupled HD and AD simulations can be made - both The range of the FEFLOW 6.0 Classic user interface for the Cartesian and Flexible Mesh versions functionality made accessible via the Standard interface includes: MIKE 11 Engine upgrade The simulation engine of MIKE 11 has been  Editing of time dependent material properties upgraded to a 64-bit application. Hence, the  Budget groups simulation speed has been increased and any  Expression based selection and assignment memory constraints during simulations have been  Convenient editor for unsaturated properties removed  Editing of discrete feature elements Tool for spatially distributed rainfall generation  Borehole heat exchanger A new tool for preprocessing of station-based  Manual mesh editing temporal data is now available for the creation of  Expression based material properties 2D spatial and temporal varying grid files using  Chemical reaction definition either the Thiessen polygons or the inverse distance  Fluid flux analyser weighting methodology MIKE SHE parallelised AD solver MIKE by DHI Facilitating tomorrows MIKE SHE’s AD solvers have been optimised for parallel processing resulting in increased model Release 2012 needs performance. This development is an extension of the parallelisation of HD solvers released in 2011 Head office: Agern Allé 5 DK-2970 Hørsholm Denmark Tel: +45 4516 9333
  7. 7. MIKE by DHI CITIES COAST & SEAWater modelling software - and much more MIKE URBAN - the complete urban water package Defining new frontiers in the marine areaDHI is the leading global provider of knowledge of water MIKE URBAN version 2012 continues to offer its users high Version 2012 of the marine products is full of newenvironments, and the MIKE product family is the main productivity and harvest the benefits from improved performance facilities designed to enhance the applications ofvehicle for making our global expertise accessible. The as well as new features like calibration plots and reports. The these products even further.MIKE products are continually being improved with the latter feature supports plots of measured and simulated data andlatest research and development carried out at one of can either show comparisons between time series or statisticalDHI’s research centres - very often in collaboration with data.leading universities or other partners. Furthermore, a new set of tools for improved usability (eg whenAccessibility is a keyword for DHIs know-how. We strive building a 1D/1D storm water model) is available for both theconstantly to provide easy and affordable access to our MOUSE and SWMM components:global knowledge. Apart from the MIKE products with  Catchment slope and length calculationstheir embedded know-how and expertise, DHI also offers  Cross section extraction from DEMa wide range of training courses in many languages and in  Lateral snapping of nodes A few selected examples:more than 30 countries worldwide.  Auto connection of overland network to storm water  Linux porting of simulation engines network The MIKE 21 and MIKE 3 simulation engines in theYou can find updated training schedules here:  Sequential labelling of nodes FM series are ported for execution on Linux computers, thus allowing simulations on massive computer clustersReliability is another keyword. You can safely rely on top Catchment delineation based on digital elevation models  MIKE Animator Plusquality software and efficient, local support and training improves the accuracy compared to pure geometrical methods. A new version of the popular MIKE Animator withfrom DHI. Your investment in MIKE software and in enhanced and improved functionalities (includingwater modelling competence is safeguarded by the fact support for MIKE 3 files)that DHI is the global leader in knowledge and modellingtechnology for water environments.  Agent based modelling A brand new module, called ABM Lab, is being launched with Release 2012. ABM Lab is used for modelling theThe MIKE by DHI Release 2012 continues the proud behaviour and fate of moving agents, typically fish ortradition of frontier developments and increased value other living organisms, in the water environment. ABMfor our users. We are confident that you will agree! Lab integrates seamlessly with ECO Lab or may be used on its own  Improved structures Important improvements in the MIKE 21 and MIKE 3 structure descriptions, including improved descriptions of tidal turbines Enhanced 2D overland flow features  2D initial conditions as a constant value - from polygons or from external polygon layers  2D water level and inflow boundaries  Spatially distributed rainfall onto a 2D grid Modelling engine enhancements of MIKE URBAN CS  An additional 1D engine, MIKE 1D, designed and optimised for parallel processing  64-bit support for the MOUSE engine
  8. 8. DHI CASE STORYHelping Atlantis tune to the tidesProviding comprehensive analyses of tidal energy resource sites Tidal flows vary greatly with geography, across the globe. Also, interaction SUMMARY between turbines within a prime spot can impact the intensity and direction of tidal flows themselves – locally and regionally. As such, the success of Client sustainable, financial risk-reduced and cost-effective tidal power generation Atlantis Resources Corporation depends on the accurate knowledge of tidal energy flow at specific sites. In (Atlantis) short, it is imperative to identify the best site within an area of interest, to Challenge make successful tidal power generation a reality. With our global experience,  Large variance in tidal flows state-of-the-art software and dedicated Decision Support System (DSS), we worldwide helped our client – Atlantis Resources Corporation – to do just that.  Inefficient utilisation of tidal energy resources Tidal turbines – heralding the future of renewable energy  Lack of knowledge on tidal site Tidal turbines take up approximately 1/1000 of the space of a wind turbine characterisation for the same yield due to the greater density of water. Also, the resource is  Financial risks and uncertainties 90% predictable. However, in order to ensure optimisation of the resource, for companies and investors it is necessary to identify an area with sufficient flow, combined with the Solution appropriate depths, at a suitable distance from land and free from shipping  Detailed site investigations and lines and other environmental impacts. analyses  Accurate site modelling and a As such, the tidal energy sector is still in the pioneering phase. In compari- dedicated Decision Support son with conventional hydropower and wind energy, tidal power is a diffi- System (DSS) cult resource to tap into and many uncertainties still surround successful  Comprehensive planning and tidal power generation. However, it is becoming increasingly likely to suc- forecasting of yield to the power ceed and at DHI, we have an important role to play in its future success. Curi- grid osity and a common sense approach are pre-requisites for development of  Recommendations for optimal tidal power generation sites any kind. These coupled with science and accuracy (numerical models) are set to make tidal power the ‘next big thing’ in the renewable energy sector. Value  Enabling the client to select optimal sites for tidal power generation  Aiding in the development of tidal power generation sites  Significant financial risk reduction for the company and investor  Marked contribution to the green/renewable energy sector  Tidal energy knowledge made globally accessible through our MIKE software Atlantis 1MW AR1000 turbine prior to installation for open ocean testing at the European Marine Energy Centre (EMEC)
  9. 9. Helping Atlantis tune to the tidesProviding comprehensive analyses of tidal energy resource sitesCharacterising tidal power sites worldwide Empowering Atlantis to make informed decisionsGlobally, we have identified many potential sites for dif- Our solution was a comprehensive analysis of each pro-ferent types of turbines. Even though just a fraction of spective turbine deployment site using our modellingthese are being developed currently, once full-scale tur- skills and experience. We make that analysis available tobine technology is proven, our service will help slash de- Atlantis in a MIKE customised-based DSS, where it canvelopment time from years to months. We have a proven freely combine its know-how from turbine design andability to assess the power resources of an area – to economics. This gives the client a simple interface to aquickly and simply screen new sites, slowly building up complex problem, by way of models which can be reusedconfidence in potential sites to go hand in hand with time and again for different environmental approvals,planned investments. detailed planning and even forecasting of the yield to the power grid.The inability to develop a site due to uncertainties, lim-ited knowledge of the site and associated constraints pos- By reducing uncertainties, we empowered Atlantis withes great risks for investors and companies alike. Atlantis the information required to convince developers aboutwas on the lookout for prospective sites for tidal power the feasibility of certain sites for tidal power generation.generation and it needed to quickly and accurately deter- Today, construction of the world’s largest planned tidalmine which sites were the most promising for prospec- power project– MeyGen (398MW), will commence soon intive development. Atlantis needed certainty and a partner the Pentland Firth, Scotland. Its completion is scheduledwho believed in its ideas and was prepared to join it on for 2019. Issues related to array effects and optimisationthe entire journey. We were exactly what Atlantis was still persist. We are meeting these challenges by engaginglooking for and it contacted us seven years ago to begin a researchers worldwide, involving ourselves in internalglobal search for areas with high tidal currents. research and integrating state-of-the-art knowledge on a daily basis into our MIKE software and MIKE customisedBased on our recommendations, Atlantis started ap- online interfaces and services.proaching governments for rights to exploit tidal re-sources within their respective countries. Once the areas Spreading our knowledge globally – making it ac-were secured, we were free to assess the resource further cessiblethrough different project phases, with quantifiable and By being early entrants into the tidal power world, wedeclining uncertainties throughout. We have assessed a have accumulated novel knowledge, which was encapsu- lated in our MIKE by DHI software. It has thereby beendozen such sites globally. made available globally and is being used by nearly all site and turbine developers. Thus, our tidal knowledge is significantly benefitting the tidal energy industry. In a recent review by the U.K. Crown Estate, it was found that of all the bidders that have won rights to install tidal and wave arrays around the U.K., more than 90% used the MIKE by DHI software. (All images © Atlantis Reources Corporation) August2012 © DHI The long lasting effects of a trusting relationship Our success in the site selection process for Atlantis stems from our long relationship with the latter. Together with our client, we have achieved deep trust and understand- ing. It is a shining example of how implicit trust, in-depth scientific knowledge, global expertise and the willingness to go forward, can lead to better and greener solutions for the planet. Client testimonial “DHI has been by our side and helped us from the early inception till today – and we look forward to continued close collaboration in the future.” Timothy Cornelius, CEO, Atlantis Resources Corporation Final assembly test in the dry between turbine nacelle and test foundation Contact: Marketing -
  10. 10. DHI CASE STORYPredicting scour in offshore wind turbines – now a breezeMaking offshore wind energy more viable with long-term scour prediction tools The total offshore wind power capacity is expected to touch 75GW by 2020 and SUMMARY the possibilities are immense. However, the offshore wind energy industry is still stricken with the burden of heavy capital investments. Our newly Client developed tool – ‘WiTuS’ can lighten that load. With WiTuS, we can predict This is a research project funded by long-term mono pile scouring – this can help in simplifying turbine designs, the Danish Council for Strategic effectively reducing the investment required. Research (DFS)/Energy and Environment Offshore wind farms demand a heavy price Challenge Offshore wind power refers to electricity generated from wind in wind farms  Protect wind turbine constructed in water bodies. Offshore wind farms are expensive – invest- foundations against scour ment prices can touch €3million/MW. The installation of the offshore wind  Heavy investment (up to turbine is a complex procedure. It generally comprises one third to half of €150,000/turbine) in scour protection due to lack of long- the total investment in the wind farm, while the rest is comprised of infra- term predictability structure, maintenance and oversight. Also larger turbines with more energy capture capability, make more economic sense, when starting an offshore Solution wind project. Thus, the larger the turbines, the greater the investment costs. Our tool ‘WiTuS’ enables prediction of scour around mono piles over The mono pile – rooted in movement long time spans Although deep water floating wind turbines are being developed, most off- shore wind farms today still utilise traditional fixed-bottom foundation tech- nologies. Different types of foundations are used depending on the depth of Value water at which the turbine is being installed. These include monopile, gravi-  Long-term scour predictions can ty based, tripod, suction bucket and conventional steel jacket structures. Of slash scour protection invest- these, monopile foundations have been the preferred foundation type so far. ments by as much as €150,000/ This is owing to the fact that they have an edge over other foundation types turbine –this is approximately 6- in shallow water, mainly with regards to construction, production, assembly 10% of the total average project and cost efficiency. cost  This tool is customized to fore- A monopile foundation utilises a single pile structure driven 10-40m into the cast scour around monopiles. However, it can be applied to seabed depending on the any offshore and coastal pile- expected loads on the structure where long-term scour wind turbine. When the development is an issue monopile is installed, it  If the environmental conditions rises 10-15m above the are predicted, scour develop- mean sea level. The wind ment around the structure can turbine is later placed be better forecasted above it. As such, the monopile has to support all the loads on and from the wind turbine as well as loads from waves on the foundation. Example of a predicted scour hole, using WiTuS
  11. 11. Predicting scour in offshore wind turbines – now a breezeMaking offshore wind energy more viable with long-term scour prediction toolsMany of the planned offshore wind farms are going to be With WiTuS, we can predict long-term scour develop-installed on monopile foundations at water depths rang- ments around monopile foundations. By becoming capa-ing between 10-30m and generally at distances within ble of predicting the exact scour/erosion depth, the esti- mations of loads and the fatigue life of the wind turbine12km from the shore. The coastal sediments in these are- can be improved. Armed with such predictive infor-as are often defined by sand and silt, making the seabed mation, you can opt for simpler and cheaper designs forvery mobile. At such locations, the wave and current in- your wind turbine, without compromising on safety.teraction with the foundation has a significant effect on For example, for some wind farms, where only a verythe total load on the turbine (nearly 50%). One of the light scour is predicted, it might be more economical tomost prominent risks to the offshore foundations is discard the idea of scour protection altogether. However,scouring, which occurs due to the constant wave and cur- in some areas, it is not wise to leave monopiles unprotect- ed. It is a well-known fact that horseshoe vortices are ma-rent action. jorly responsible for scour around unprotected mono- piles, especially where the current action is more promi-Scour risks and steep prices – why scour prediction nent. The vortices from the horseshoe and the lee-wakeis the need of the hour are also known to undercut scour protection. WithThe presence of a monopile in a marine environment WiTuS, we can take these variables into consideration,changes the flow pattern in its immediate neighbourhood, when foresting long-term scour developments in suchresulting in an increased local sediment transport. This areas. Accordingly, you can plan the accurate measure ofcauses scouring of the seabed around the monopile – in scour protection for your wind turbine foundation and save on investment costs in the process.layman’s terms, it is ‘eaten away’. This is a serious risk. Ifthere is excessive excavation of the immediate seabed, thestability of the wind turbine foundation can be gravelycompromised. Also, the structure can suffer increasedhydraulic loading. The cables on the seabed whichtransport electricity generated by the turbine, can be ex-posed to bending stresses beyond the design conditions,due to the eroded seabed around the monopile. Owing tothe abovementioned threats, monopiles have to be pro-tected against the effects of scouring. Although such pro-tective measures are available, the dearth of long-termscour forecasting makes it imperative to heavily invest infortification of the monopile. Today, scour protection forone wind turbine is estimated at €80,000 to €150,000.This is a steep price to pay and it adds on to the alreadyhigh investment costs of setting up an offshore wind farm. Typical shape of a scour hole around a monopileIf long-term predictions of scour development can be made,heavy investments in scour protection measures can beoffset to a large extent. More to it than meets the eye  WiTuS empowers you to forecast the scour develop-Gaze into the future with our tools, save on invest- ment at a monopile more accurately, if environmental conditions in that area are predicted with similar accu-ments racy.Scour has been studied extensively in the past few dec-ades, but very few investigations have been dedicated to  The special advantage of this tool is that, it can be used for any kind of offshore and coastal pile structure,the long-term forecasting of scour around offshore struc- where scour development over long time spans is atures. Tide motions give rise to coastal currents, which inturn emerge as the primary driving forces of scour. Differ- hindrance or an issue.ent coastal and offshore sites which have been identifiedfor wind farm development, can differ significantly interms of coastal bathymetry, shoreline geomorphology & July2012 © DHIorientation and exposure to the effects of waves and cur-rents. Also the sediment composition at each site isunique to itself. All these factors and variables have to betaken into account when studying the scour aroundmonopiles. Contact: Martin Dixen -
  12. 12. Weather radars – A new pair of eyes for offshore wind farms? PO. ID Pierre-Julien Trombe1 Pierre Pinson1 Claire Vincent2 Henrik Madsen1 Niels E. Jensen3 Thomas Bøvith4 Nina F. Le5 Anders Sommer6 75 (1) Technical University of Denmark, DTU Informatics, Denmark (2) Technical University of Denmark, DTU Wind Energy, Denmark (3) Danish Hydraulic Institute (DHI), Denmark (4) Danish Meteorological Institute (DMI), Denmark (5) DONG Energy, Denmark (6) Vattenfall Danmark A/S, Denmark Background Experimental Setup The substantial impact of wind power fluctuations at A Local Area Weather Radar (LAWR, X-band, from DHI) large offshore wind farms calls for the development of was installed at Horns Rev in the frame of the Danish dedicated monitoring and short-term (0-6 hours) project Radar@Sea prediction approaches Additional Radar images are available from a Doppler Recent observations at the offshore site of Horns Rev radar (C-band) at Rømø on the west coast of Denmark revealed the presence of convective rain cells as a meteorological indicator for extreme wind variability and suggested the use of weather radars for detecting and tracking such phenomena (Vincent et al. 2011) Typical situation of Open Cellular Convection over the North Sea west of Denmark Objectives and MethodologyResults / Example Episodes Our objectives are  To monitor weather conditions in the vicinity of the offshore wind farm (for environmental studies, security of onsite personnel, etc.)  To characterize the local weather phenomena that lead to enhanced power fluctuations  To embed that knowledge in forecasting methodologies so as to obtain improvedTypical fall and predictionswinter situations  To account for this regime-switching behavior in the wind farm controller with large weather fronts Time-series of wind and power observations are modeled so as to highlight their mean and trailing behavior and variability, as well as regime-switching aspects, with precipitation  Unobserved regime sequences (MSAR-GARCH statistical models – Trombe et al. (2012)) cells affectingwind and power  Observed regime sequences (based on explanatory variables eg. wind direction or based on fluctuations the information given by radar images) Methods from image analysis are used to extract and track features in images from both radarsTypical summer situation withsummer storms hitting the offshore wind farm References / Further Reading Conclusions Pinson P, Madsen H (2012) Adaptive modeling and forecasting of wind power fluctuations with Markov- switching autoregressive models. Journal of Forecasting, available online Pinson P (2012) Very short-term probabilistic forecasting of wind power with generalized logit-Normal Weather radars may become crucial onsite remote-sensing distributions. Journal of the Royal Statistical Society, Series C, available online instruments for future large offshore wind farms Trombe P-J, Pinson P, Madsen H (2012) A general probabilistic forecasting framework for offshore wind power fluctuations. Energies 5: 621-657 Significant collaborative R&D with meteorologists, radar Vincent CL, Hahmann AN, Kelly MC (2011) Idealized mesoscale model simulations of open cellular convection experts, forecasters and wind farms operators is required over the Sea. Boundary-Layer Meteorology 142: 103-121 to fully exploit the new information provided by such Vincent CL, Pinson P, Giebel G (2011) Wind fluctuations over the North Sea. International Journal of remote-sensing instruments Climatology 31: 1584-1595 Acknowledgements: This work is supported by the Danish Public Service Obligation (PSO) fund project Radar@Sea (under contract PSO2009-1-0226) which is gratefully acknowledged. We are grateful to the Danish Meteorological Institute (DMI) for sharing the data from the Rømø radar. We also thank Vattenfall and DONG Energy respectively, for providing wind power data from the Horns Rev 1 wind farm and the images generated by the LAWR. Thanks also to for the satellite image. EWEA 2012, Copenhagen, Denmark: Europe’s Premier Wind Energy Event