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

1. CONFERENCE NEWSLETTER
Marine Renewable Energy – Meeting the Need
University of Plymouth, Monday 1 October 2012
NEWS RESEARCH
TeraWatt project – large scale interactive coupled 3D Radar @ Sea – prize winning poster at EWEA 2012 wind
modelling for wave and tidal energy resource and energy conference
environmental impact using MIKE by DHI software
Wind power fluctuations strongly affect offshore wind farms.
Weather radars offer a promising tool for the development of a
Scotland has substantial wave and tidal energy resources and is at the
dedicated monitoring and short-term prediction system. A
forefront 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 future
deployed in arrays, with many sites being developed. It is therefore
expectations at the EWEA 2012 event in Copenhagen. The
essential to understand how a number of multi-site developments
research project suggests how the use of weather radar can
collectively impact on the physical and biological processes over a
improve operations for offshore wind farms, giving early
wider 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 environmental
impacts 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 and
Physical Sciences Research Council through its Marine Challenge Fund.
The project consortium has been established under the auspices of the
CASE STORY
Marine Alliance for Science and Technology for Scotland (MASTS) with Supporting tidal energy - metocean design conditions in
scientists from the Universities of Heriot-Watt, Edinburgh, Highlands the Pentland Firth
and Islands, Strathclyde, Swansea and Aberdeen, and Marine Scotland The Pentland Firth in Scotland is one of the most energetic
Science (MSS). marine sites in Europe making it highly attractive for tidal energy
projects. However, the site is also exposed to severe wave
The overarching objective of the research is to generate a suite of conditions, presenting a very challenging environment for such
methodologies that can provide a better understanding of the impact of activities.
energy extraction on the resource. Approaches will also be developed
that can be employed to assess the physical and ecological The MeyGen tidal stream project plans to build a 398MW turbine
consequences of changes to the resource. The project objective will be array – generating electricity equivalent to that required to
met 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 turbine
on organisms living in the seabed, their distribution and the superstructure, MeyGen commissioned us to provide design
significance 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 the
support their research. Coupled MIKE 3 FMHD and MIKE 21 SW characteristics of the wave climate. In conditions where tidal
models 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 of
MIKE 3 FMST, LITPACK, MIKE 3 FM ECO Lab & ABM Lab, EVA and similar steepness to those observed. Our results will be used by
MIKE Animator in order to consider the specific responsibilities of each MeyGen to further optimise their turbine design and ensure that
partner 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. Marine Renewable Energy – Meeting the Need
University of Plymouth, Monday 01 October 2012
CASE STORY RESEARCH
Helping Atlantis tune to the tides EPSRC project partner – optimal design of very large tidal
stream farms for shallow estuarine applications
Tidal 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, the
intensity and direction of tidal flows themselves both locally and Exeter Centre for Water Resources (Non-SuperGen), Penn State
regionally. University, Aquascientific Ltd. and ourselves. It is mentored by
Garrad Hassan Partners. The primary goal is the introduction of a
As 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 of
tidal energy flows at specific sites. In short, it is imperative to identify
marine energy farms, subject to environmental impacts. The
the best site within an area of interest, to make successful tidal power
specific application focus involves tidal turbines suited to
generation a reality. With our global experience, state-of-the-art
operating in shallow, medium flow estuaries but the technique
software and dedicated Decision Support System (DSS), we helped our
can be applied to all types of marine energy farms. Optimisation is
client – Atlantis Resources Corporation – to do just that.
subject to minimising flood risk with further environmental
Please 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 an
RESEARCH improved and more accurate description of tidal stream energy
Predicting 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, to
form 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 type
foundations. Armed with such predictive information, you can opt
for simpler and cheaper designs for your wind turbine, without
compromising on safety. Accordingly, you can plan the accurate NEWS
measure of scour protection for your wind turbine foundation and MIKE by DHI software Release 2012
save on investment costs in the process.
We are pleased to advise that the new MIKE by DHI Software
Please 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 3
Metocean water forecast and monitoring around London simulation engines in the FM series are ported for execution on
Array wind farm, UK Linux computers, thus allowing simulations on massive computer
We 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 for
and operation of three wave and current buoys and a tide gauge; all modelling the behaviour and fate of moving agents, typically fish
equipped 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 21
are used to feed hydrodynamic models which predict the wave and and MIKE 3 structure descriptions, including improved
current 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 ECO
temperature, sea temperature, visibility, lightning risk, cloud height, Lab editor, Mesh Generator engine improved to handle larger
water levels, wave heights and currents. data sets, global tide model improvements, and more…
For more information, please visit:
 www.londonarray.com
 www.offshorerenewables.dhigroup.com
NEWS
 www.waterforecast.com
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 sjf@dhigroup.com
or visit our websites www.dhigroup.com and www.mikebydhi.com

3. RENEWABLES at DHI
Marine Renewable Energy – Meeting the Need
University of Plymouth, Monday 1 October 2012
MIKE 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. SOFTWARE SUMMARY
Marine Renewable Energy – Meeting the Need
University of Plymouth, Monday 1 October 2012
MIKE 21 / 3 FM HD
Hydrodynamic modelling in two– and three–dimensions
The Hydrodynamic Module included in MIKE 21 & MIKE 3 Flow Model FM simulates water level variations and unsteady flows in response to a
variety of forcing functions in the marine environment including density variations, bathymetry and external forcings. It also provides the
basis for computations performed in many other modules. The choice between 2D and 3D model depends on a number of factors. For
example, in shallow waters, wind and tidal current are often sufficient to keep the water column well-mixed, i.e. homogeneous in salinity and
temperature. In such cases a 2D model can be used. In water bodies with stratification, either by density or by species (ecology), a 3D model
should 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 SW
Simulating offshore and nearshore wave fields
MIKE 21 SW is a 3rd generation spectral wind-wave model that simulates the growth, decay and transformation of wind-generated waves and
swell in offshore and coastal areas. It is used for a wide range of wave climates assessments in offshore and coastal areas, both hindcast and
forecast mode, including design of offshore, coastal and port structures, where accurate assessment of wave loads is of utmost importance to
the safe and economic design of these structures.
MIKE 21 SW solves the spectral wave action balance equation formulated in
either Cartesian or spherical coordinates. At each mesh point, the wave field
is represented by a discrete two-dimensional wave action density spectrum
using either a fully spectral or directional decoupled parametric formulation.
The discretisation of the governing equations in geographical and spectral
space is performed using cell-centred finite volume method. In geographical
domain an unstructured mesh is used. The time integration is performed
using a fractional step approach where a multi-sequence explicit method is
applied for the propagation of wave action.
The model includes the following physical phenomena; wave growth by
action 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 associated
wave-induced currents. The wave-induced current is generated by the gradients in radiation stresses that occur in the surf zone. MIKE 21 SW
can be used to calculate the wave conditions and associated radiation stresses. The long-shore currents and sediment transport is then
calculated using the flow and sediment transport models available in the MIKE 21 package.

5. Marine Renewable Energy – Meeting the Need
University of Plymouth, Monday 01 October 2012
ECO Lab & ABM Lab
Assessing impacts on the marine environment and its populations
MIKE 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 21/3
ECO Lab FM a powerful tool. MIKE 21/3 ECO Lab FM is typically applied in environmental water quality studies in coastal areas, estuaries, and
lakes.
MIKE 21/3 ECO Lab FM is capable of simulating the spatial distribution of state variable concentrations in a 2D or 3D domain based on
processes 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 templates
are supplied with the model including eutrophication, water quality and heavy metals. The ECO Lab template is independent of the horizontal
discretization 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 is
possible 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 of
environmental conditions (bathymetry, flow, water level, temperature, salinity and many other parameters; including water quality).
LITPACK
Shoreline evolution and littoral processes
LITPACK is a deterministic numerical modelling system which describes the major processes in the nearshore zone. The main sediment
transport engine and boundary condition data are derived from the MIKE 21 / 3 modelling suite, ensuring a coherent approach to any
assessment. The individual modules of the LITPACK suite simulate different coastal processes, with the linking between modules being
performed by an automatic control module. This allows rapid simulation of complex coastal problems without loss of detail in the individual
modules. The processes covered by the individual modules can be
broadly 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 sjf@dhigroup.com
Visit our websites www.dhigroup.com and www.mikebydhi.com

6. WATER RESOURCES GROUNDWATER & POROUS MEDIA
Reshaping the scene of water resources FEFLOW
Release 2012 provides a range of significant new FEFLOW 6.1 sets a new standard in groundwater
developments and features for the water resources modelling by providing the entire range of its
software products. functionality in one modern user interface.
In addition to introducing a new GUI, FEFLOW 6.1
Selected 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
tomorrow's
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
mikebydhi@dhigroup.com
www.dhigroup.com

7. MIKE by DHI CITIES COAST & SEA
Water modelling software - and much more MIKE URBAN - the complete urban water package Defining new frontiers in the marine area
DHI 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 new
environments, and the MIKE product family is the main productivity and harvest the benefits from improved performance facilities designed to enhance the applications of
vehicle 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 and
latest research and development carried out at one of can either show comparisons between time series or statistical
DHI’s research centres - very often in collaboration with data.
leading universities or other partners.
Furthermore, a new set of tools for improved usability (eg when
Accessibility is a keyword for DHI's know-how. We strive building a 1D/1D storm water model) is available for both the
constantly to provide easy and affordable access to our MOUSE and SWMM components:
global knowledge. Apart from the MIKE products with  Catchment slope and length calculations
their embedded know-how and expertise, DHI also offers  Cross section extraction from DEM
a 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 the
You can find updated training schedules here:  Sequential labelling of nodes FM series are ported for execution on Linux computers,
www.mikebydhi.com/Training.aspx thus allowing simulations on massive computer clusters
Reliability is another keyword. You can safely rely on top Catchment delineation based on digital elevation models
 MIKE Animator Plus
quality software and efficient, local support and training improves the accuracy compared to pure geometrical methods.
A new version of the popular MIKE Animator with
from DHI. Your investment in MIKE software and in enhanced and improved functionalities (including
water modelling competence is safeguarded by the fact support for MIKE 3 files)
that DHI is the global leader in knowledge and modelling
technology 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 the
The MIKE by DHI Release 2012 continues the proud behaviour and fate of moving agents, typically fish or
tradition of frontier developments and increased value other living organisms, in the water environment. ABM
for 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. DHI CASE STORY
Helping Atlantis tune to the tides
Providing 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. Helping Atlantis tune to the tides
Providing comprehensive analyses of tidal energy resource sites
Characterising tidal power sites worldwide Empowering Atlantis to make informed decisions
Globally, 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 modelling
these are being developed currently, once full-scale tur- skills and experience. We make that analysis available to
bine technology is proven, our service will help slash de- Atlantis in a MIKE customised-based DSS, where it can
velopment time from years to months. We have a proven freely combine its know-how from turbine design and
ability to assess the power resources of an area – to economics. This gives the client a simple interface to a
quickly and simply screen new sites, slowly building up complex problem, by way of models which can be reused
confidence 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 with
es great risks for investors and companies alike. Atlantis the information required to convince developers about
was 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 tidal
mine which sites were the most promising for prospec- power project– MeyGen (398MW), will commence soon in
tive development. Atlantis needed certainty and a partner the Pentland Firth, Scotland. Its completion is scheduled
who believed in its ideas and was prepared to join it on for 2019. Issues related to array effects and optimisation
the entire journey. We were exactly what Atlantis was still persist. We are meeting these challenges by engaging
looking for and it contacted us seven years ago to begin a researchers worldwide, involving ourselves in internal
global 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 customised
Based 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 cessible
through different project phases, with quantifiable and By being early entrants into the tidal power world, we
declining uncertainties throughout. We have assessed a have accumulated novel knowledge, which was encapsu-
lated in our MIKE by DHI software. It has thereby been
dozen 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 - marketing@dhigroup.com

10. DHI CASE STORY
Predicting scour in offshore wind turbines – now a breeze
Making 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. Predicting scour in offshore wind turbines – now a breeze
Making offshore wind energy more viable with long-term scour prediction tools
Many 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 turbine
12km 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 for
very 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 very
the total load on the turbine (nearly 50%). One of the light scour is predicted, it might be more economical to
most 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-wake
is the need of the hour are also known to undercut scour protection. With
The 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 such
resulting in an increased local sediment transport. This areas. Accordingly, you can plan the accurate measure of
causes 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. If
there is excessive excavation of the immediate seabed, the
stability of the wind turbine foundation can be gravely
compromised. Also, the structure can suffer increased
hydraulic loading. The cables on the seabed which
transport 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 to
the abovementioned threats, monopiles have to be pro-
tected against the effects of scouring. Although such pro-
tective measures are available, the dearth of long-term
scour forecasting makes it imperative to heavily invest in
fortification of the monopile. Today, scour protection for
one wind turbine is estimated at €80,000 to €150,000.
This is a steep price to pay and it adds on to the already
high investment costs of setting up an offshore wind farm.
Typical shape of a scour hole around a monopile
If long-term predictions of scour development can be made,
heavy investments in scour protection measures can be
offset 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 a
tures. Tide motions give rise to coastal currents, which in
turn emerge as the primary driving forces of scour. Differ- hindrance or an issue.
ent coastal and offshore sites which have been identified
for wind farm development, can differ significantly in
terms of coastal bathymetry, shoreline geomorphology &
July2012 © DHI
orientation and exposure to the effects of waves and cur-
rents. Also the sediment composition at each site is
unique to itself. All these factors and variables have to be
taken into account when studying the scour around
monopiles.
Contact: Martin Dixen - mdi@dhigroup.com

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 Methodology
Results / 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 improved
Typical fall and predictions
winter 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 affecting
wind 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
radars
Typical summer
situation with
summer 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 http://www.eumetrain.org/ for the satellite image.
EWEA 2012, Copenhagen, Denmark: Europe’s Premier Wind Energy Event