SuperGen UK Centre for Marine Energy Research
TeraWatt - Assessing the impact of multi-site
arrays on the physical and biological
processes over a wider region.
UKCMER
TERAWATT ~ THE RESEARCH QUESTIONS
In response to questions posed by Marine Scotland Science
TERAWATT seeks to answer and address:
Industry input led to the selection of MIKE and
Delft3D for modelling during formative discussions
with developers and others on the proposal.
UKCMER
1) What is the best way to assess wave and tidal
energy resources, and feedbacks on energy
extraction, in certain geographical areas?
2) What are the physical consequences of wave
and tidal energy extraction?
3) What are the ecological consequences of
wave and tidal energy extraction?
4) The development of standard hydrographic
modelling methodologies for wave and tidal
developments.
UKCMER
TERAWATT ~ EPSRC GRAND CHALLENGE 1 FUNDING
TeraWatt: Partners and Management:
Multi-institution EPSRC research project established under
the Marine Alliance for Science and Technology Scotland (MASTS),
involving the Universities of
• Heriot-Watt,
• Edinburgh,
• Highlands and Islands (LCC and SAMS),
• Glasgow (now Swansea),
• Strathclyde
• and with Marine Scotland Science as full consortium partners.
Regular reporting though a Steering Group and UKCMER, with a
Project Management Committee and regular open door
workshops drawing in device and software developers and
related PhD projects
MASTS play a key role in organising Steering Group Meetings
and participation in outreach activities.
UKCMER
TERAWATT ~ THE WORKSTREAMS AND MANAGEMENT
UKCMER
TERAWATT ~ WORKSTREAM 1: Role of Marine Scotland Science
• Formulation of, monitoring progress against, research questions
• Facilitation of data management – now through FTP site
• Data acquisition – release of previously unavailable data
• Realistic Array Scenarios – developed but updating as needed
• Knowledge exchange and stakeholder engagement – e.g. hosting key workshop on incorporation of energy extraction for generic devices in Mike and Delft3D models in March 2014
• Acceptability of impacts at the licensing stage – under development and considerations within the EU Marine Strategy and Water Framework Directives
Data now available via Marine Scotland Science FTP site:-
• BGS sediments data
• Multibeam bathymetry data from UKHO, TCE, MSS
• Bay of Skaill bathymetry data
• 3x ADCP in Pentland Firth from MCA/Guardline
• TCE models and bathymetry data
• Bathymetry data compilation by Halcrow for SSM
• UKHO VORF data for vertical datum corrections
• TCE 20 m bathymetry grid based on multibeam
and Defra DEM product.
• ADCP, CTD, and met data from sound of Hoy – Dec 2012
• Stronsay Firth ADCP mooring – May 2013
• Stronsay Firth ADCP transect – May 2013
• Pentland Firth transects – May 2013
• Current meter moorings from FI channel – 2001
• Brahan HF radar, now available
• 3 x seaguard current meters and 1 x AWAC in FI channel
May – Oct 2013
• The Brahan Project
TERAWATT ~ WORKSTREAM 1: Role of Marine Scotland Science
www.thebrahanproject.com
UKCMER
THE BRAHAN PROJECT
Providing near real time
tidal current data within
part of the domain
modelled in MIKE and
Delft3D using CODAR
radar.
Data freely available from
website:-
TERAWATT ~ WORKSTREAM 1: Role of Marine Scotland Science
UKCMER
• Gridded
bathymetric data
at 20m resolution
• Realistic array
scenarios
Sandy RiddleSandwaves
Inner Sound
Validation of Hm0 for different periods at various locations
Validation is also carried out for Tp and wave direction
Model provided boundary conditions to other work streams
TERAWATT ~ WORKSTREAM 2: North Atlantic Wave ModelUKCMER
TERAWATT ~ WORKSTREAM 2: Wave Energy Extraction
Change in significant wave height from a wave array at Brough Head,West Coast Orkney Mainland
A single generic tidal
turbine and several
generic wave energy
devices were agreed at
the March 2014 TeraWatt
Industry /Government
Workshop, together with
their characteristics and
means of incorporating
within the models
developed. Published now
as a position paper.
Hosted by Marine
Scotland Science and
MASTS
Flood current Ebb current
TERAWATT ~ WORKSTREAM 2: Developing MIKE Flow modelsUKCMER
TERAWATT ~ WORKSTREAM 2: Developing Flow models
Earlier Delft3D grid used to investigate sensitivity of model parameterisation against 3 ADCP deployments in the Pentland Firth:-
Little difference found in application of different turbulence closure approaches, see Baston et al., 2013.
But model extremely sensitive to bottom friction parameterisation; insufficient data to enable the investigation of spatially varying bed resistance.
White-Colebrook spatially variable
bottom friction using FT approach
Change in mean current speed with tidal energy extraction in the Inner Firth
TERAWATT ~ WORKSTREAM 2: Flow models with tidal arrays
Change in one
month mean
depth averaged
current speed
with energy
extraction in
MIKE3D (top
and LHS) and
Delft3D (RHS)
TERAWATT ~ WORKSTREAM 2: Comparing MIKE with CFX
100m mesh, 10 sigma layers Variable mesh: 8-10m to <1m, 10 sigma layers
• Attenuation of light intensity with depth,
affects phytoplankton and macrophyte
primary production, and the environment
for visual predators.
• Detailed data on SSC are relatively
scarce, so both dynamic and statistical
models which may predict SSC from
more readily available data are
potentially valuable.
• Analysis of >400 turbidity profiles
collected at weekly intervals during 2007-
2011 at the Marine Scotland Science
sampling site off Stonehaven on the east
of Scotland.
• General Additive Model (GAM) of SSC
at a given altitude above the seabed with
explanatory variables being tidal range,
wind and wave, and height above the
seabed.
• 5 different ranges were used for
averaging waves and wind and taking
tidal range (6/12/24/48/72 hours) and all
combinations of these gave 125 GAMs to
choose between.
• Alternative models were assessed with
Akaike's Information Criterion (AIC) to
choose between the fits offered by different models.
Sea surface values
Low salinity (river discharge)
Storm event
Clear correlation between sediment re-suspension events and peak spring tides
14
TERAWATT ~ WORKSTREAM 3: Modelling of suspended sediment off Stonehaven
Analyses of unique data set of
suspended solids concentration
off Stonehaven
UKCMER
Presented as an ePoster at MASTS Annual Science Meeting 2013
• The GAM explained 92.2% of the variability in the data.
• We see in Fig 1., and most notably in Fig 2., that the
GAM does less well at predicting the turbidity closest
to the seabed, with the best fits being seen nearer the
surface, where turbidity is lower.• Predictions are also poorest in winter
• One factor that may explain this is changes in river discharge at
different times of year.
• This method of utilising a GAM, driven by output from MIKE, was
to be transferred to predict suspended sediment in the PFOW
models.
• BUT no suitable PFOW data
• Satellite data being investigated
15Fig. 1
Fig. 4Fig. 3
Fig. 2
Predicted vs. observed turbidity
Predicted and observed
turbidity for the time series
TERAWATT ~ WORKSTREAM 3: Modelling of suspended sediment off Stonehaven
UKCMER
Model mesh
Calibration against ADCP data
LHS: top ~ Stroma sandwaves, bottom ~ Sandy Riddle with energy extraction over 1 lunar month. RHS: difference from the natural case
TERAWATT ~ WORKSTREAM 3: Sediment Transport in the Pentland Firth
UKCMER
TERAWATT ~ WORKSTREAM 3: Sediment Transport in the Inner Sound
Sand coverage inside the Inner Sound Channel. Continuous black lines denote the extent
of sandbanks A,B,C. The intermediate areas are covered by scoured bedrock.
UKCMER
Disruption to residual gyre that maintains Sandbank A
Cumulative erosion/accretion of sandbank A (left) and B (right) over one month period (from 09/09/2001 to 09/10/2001)
TERAWATT ~ WORKSTREAM 4: Ecological modellingUKCMER
• Outputs from Workstreams 2 and
3, expressed as bottom stress,
without energy extraction, will be
used in statistical models that
characterise benthic biotopes and
species distribution in terms of
physical parameters, leaving a
partial dataset for each for
validation.
• The WS2 and WS3 model
outputs, with energy extraction,
will be used to project possible
change under energy extraction
scenarios.
• Approaches being trialled include
Maxent for species incidence
data and boosted regression
trees for species abundance data,
which looks more promising than
GAM approaches.
Biological Data + Environmental Data
Statistical model of spatial distributions
TERAWATT ~ WORKSTREAM 4: Ecological modellingUKCMER
-10
-5
0
5
10
0 10 20 30 40 50
% C
han
ge in
Inci
de
nce
% Reduction in Significant Wave Height
Aetea anguina
Alcyonidium diaphanum
Alcyonidium hirsutum
Celleporella hyalina
Cribrilina punctata
Electra pilosa
Escharella immersa
Flustrellidra hispida
Membranipora membranacea
Microporella ciliata
Parasmittina trispinosa
Scrupocellaria scruposa
WAVEPENTLAND FIRTH
Models with energy extraction
scenarios from WS2 and WS3
Biological Data + Environmental Data
Statistical model of modified spatial distributions
Change gD
isp
lace
me
nt d
UNACCEPTABLE
MITIGATIONREQUIRED
SAFE
+ve-ve
XScenario s
dlimit
dthreshold
glimit gthreshold
Baston S, Harris R E, Woolf D K, Hiley R A, and Side J (2013). Sensitivity Analysis of the Turbulence Closure Models in the Assessment
of Tidal Energy Resource in Orkney. Proceedings of the 10th EWTEC Conference, Aalborg, Denmark. 2-5 September 2013.
Baston S (2013). Implementation of Delft3D model in Orkney Waters. Young Coastal Scientists and Engineers Conference (YCSEC) 25-
26 March 2013 in Aberdeen.
Baston S (2014). Tidal modelling and environmental impacts. The Royal Society - International Scientific Seminar India-UK. March
2014. Edinburgh.
Chatzirodou A and Karunarathna H (2014). Impacts of tidal energy extraction on sea bed morphology. 10th Young Coastal Scientists
and Engineers Conference, Cardiff, UK.
Chatzirodou A and Karunarathna H (2014). Numerical modelling of sea bed morphodynamics associated with tidal energy extraction.
3rd Oxford Tidal Energy Workshop 7-8 April 2014, Oxford, UK
Chatzirodou A and Karunarathna H (2014). Impacts of tidal energy extraction on sea bed morphology, 34th International Conference
in Coastal Engineering, Seoul, Korea.
Chatzirodou A and Karunarathna H (2015). Modelling the morphodynamic response of subtidal sandbanks to tidal energyextraction, 3rd IMA International Conference on Flood Risk, Swansea, UK.
Chatzirodou A and Karunarathna H (2015). Modelling the response of subtidal sandbank dynamics to tidal energy extraction, 36th
IAHR Congress, Hague, The Netherlands.
Fairley I, Masters I, and Karunarathna H (2015). “The cumulative impact of tidal stream turbine arrays on sediment transport in the
Pentland Firth.” Renewable Energy 80:755-769
Fairley I, Karunarathna H and Masters I (2015). “Sediment transport in the Pentland Firth and impacts of tidal stream energy
extraction” Proceedings 11th EWTEC, Nantes, France, 6-11th September
Fairley I and Karunarathna H (2014). Morphodynamics in the lee of wave energy converter arrays, Proc. 2nd International Conference
on Environmental Interactions of Marine Renewable Technologies, Stornoway, Isle of Lewis, Scotland.
Fairley I and Karunarathna H (2014). The impact of tidal stream energy extraction on sub-tidal sandbanks in the Pentland Firth,
Scotland, 10th Young Coastal Scientists and Engineers Conference, Cardiff, UK.
Goddijn-Murphy L M, Woolf D K and Easton M C (2013). Current patterns in the Inner Sound (Pentland Firth) from underway ADCP
data. Journal of Atmospheric and Oceanic Technology. 30, pp 96-111.
Greenwood C E and Christie D (2014). A frequency independent method for the simulation of Disturbances around a small scale wave
farm using a Boussinesq simulation. Proceedings of the 2nd International Conference on Environmental Interactions of
Marine Renewable Energy Technologies, Stornoway, Isle of Lewis, Scotland.
TERAWATT ~ Published outputs and Knowledge Exchange Activities
Masters I, Williams A, Croft TN, Togneri M, Edmunds M, Zangiabadi E, Fairley I and Karunarathna H (2015). A Comparison of Numerical
Modelling Techniques for Tidal Stream Turbine Analysis” Energies 07/2015: 7833-7853
McCaig C, Sabatino A, and Heath M R (2013). Statistical modelling of suspended sediment off Stonehaven. Poster presentation to the
MASTS Annual Science Meeting, Heriot-Watt University, Edinburgh. 27-29 August 2013.
MacIver R, Christie C, and Gleizon P (2015). Wave-Current Interaction in the Pentland Firth and Orkney Waters: Wave Field Effects. In:
Proceedings of EWTEC 12th European Wave and Tidal Energy Conference. Nantes 2015, France, 6-11 September 2015.
McNatt C, Venugopal V, Forehand D, and Payne G (2015). Experimental Analysis of WEC Wave Fields, 11th European Wave and Tidal
Energy Conference, EWTEC 2015, Nantes, France, 6-11 September.
Rahman A A and Venugopal V (2015). Inter-Comparison of 3D Tidal Flow Models Applied To Orkney Islands and Pentland Firth for
Resource Assessment, 12th European Wave and Tidal Energy Conference, EWTEC 2015, Nantes, France, 6-11 September.
Venugopal V and Nemalidinne R (2014)."Marine Energy Resource Assessment for Orkney and Pentland Waters with a coupled Wave
and Tidal Flow Model". Proceedings of the 33rd International Conference on Ocean, Offshore and Arctic Engineering, OMAE
2014, June 8-13, 2014, San Francisco, USA.
Venugopal V, Nemalidinne R and Vögler A (2015). Impact of Temporal Variation of Wind Input on Wave Parameters Prediction Using
Numerical Wave Model. In: Proceedings of EWTEC 12th European Wave and Tidal Energy Conference. Nantes, France, 6-11
September 2015.
Venugopal V and Reddy N (2015). Wave resource assessment for Scottish waters using a large scale North Atlantic spectral wave
model, Journal of Renewable Energy. 76, April 2015, p. 503-525, doi:10.1016/j.renene.2014.11.056.
Waldman S, Miller C, Baston S and Side J, (2014). “Comparison of two hydrodynamic models for investigating energy extraction from
tidal flows”, poster at 2nd International Conference on Environmental Interactions of Marine Renewable Energy Technologies
(EIMR), Stornoway, 2014.
Waldman S, Nemalidinne R and Baston S (2015). “Implementation of tidal turbines in hydrodynamic models of Pentland Firth and
Orkney Waters”. Poster at INORE Symposium, Naples, May 2015.
Waldman S, Genet G, Baston S and Side J (2015). Correcting for mesh size dependency in a regional model’s representation of tidal
turbines. In: Proceedings of EWTEC 12th European Wave and Tidal Energy Conference. Nantes 2015, September 2015.
Published during the work; plus a few more in press and under preparation
TERAWATT ~ Published outputs and Knowledge Exchange Activities
A “toolbox” of methods to better understand and assess the effects of tidal and
wave energy arrays on the marine environment. Published in book and
electronic versions by MASTS.
O’Hara Murray R (2015). Data acquisition and processing for TeraWatt, pp 9-29 in TeraWatt
Position Papers. ISBN 978-0-9934256-0-8
O’Hara Murray R (2015). Tidal stream and wave energy array scenarios for the Pentland Firth
and Orkney Waters Strategic Area, pp 31-47 in TeraWatt Position Papers. ISBN 978-0-
9934256-0-8
MacIver R, Reddy N and Venugopal V (2015). Representing wave enegy extraction in regional
scale numerical models, pp 49-73 in TeraWatt Position Papers. ISBN 978-0-9934256-0-8
Baston S, Waldman S and Side J (2015). Modelling energy extraction in tidal flows, pp 75-107
in TeraWatt Position Papers. ISBN 978-0-9934256-0-8
Fairley I and Karunarathna J (2015). Modelling the impacts of marine energy extraction on non-
cohesive sediment transport and morphodynamics, pp 109-129 in TeraWatt Position
Papers. ISBN 978-0-9934256-0-8
Sabatino A, Clement R, Heath M and McKee D (2015). Use of ocean colour remote sensing to
monitor surface suspended solids, pp 129-140 in TeraWatt Position Papers. ISBN 978-0-
9934256-0-8
Heath M, Sabatino A, Serpetti N and O’Hara Murray R (2015). Scoping the impact of tidal and
wave energy extraction on suspended sediment concentrations and underwater light
climate, pp 143-166 in TeraWatt Position Papers. ISBN 978-0-9934256-0-8
Davies I (in preparation). Towards an understanding of significance and acceptance criteria for
environmental impacts from energy extraction. To be added to TeraWatt Position
Papers (electronic version). ISBN 978-0-9934256-1-5
Bell M and Burrows M (in preparation). Statistical models of biological change from energy
extraction. To be added to TeraWatt Position Papers (electronic version). ISBN 978-0-
9934256-1-5
TERAWATT ~ Position Paper Publication
Provides a full and
detailed account of the
“toolbox”
methodologies
developed by the
TeraWatt Consortium
TERAWATT ~ Journal Special Issue
Introduction to and Overview of the TeraWatt Research J Side (Heriot-Watt University) M James (Marine Alliance for Science and Technology Scotland) I Davies (Marine Scotland Science) M Heath
(University of Strathclyde), H Karunathra (University of Swansea) V Venugopal (University of Edinburgh) A Vögler and M Burrows
(University of the Highlands and Islands)
Data acquisition and the development of realistic tidal and wave energy scenarios for
numerical modelling of Orkney Islands waters, Scotland Lead Author: Rory O’Hara Murray (Marine Scotland Science)
Implementation of tidal turbines in MIKE3 and Delft3D models of Pentland Firth & Orkney
Waters S Waldman, S Baston, J Side (Heriot-Watt University), R Nemalidinne, V Venugopal (University of Edinburgh), A Chatzirodou (Swansea
University)
Numerical modelling of wave energy resources and assessment of wave energy extraction
by large scale wave farms V Venugopal, R Nemalidinne (University of Edinburgh), R MacIver, A Vögler (University of the Highlands and Islands) and Tay Zhi Yung
(University of Edinburgh)
Effects of marine energy extraction on non-cohesive sediment transport and morphological
change in the Pentland Firth and Orkney Waters. I Fairley, A Chatzirodou and H Karunarathna (Swansea University)
Modelling the effects of energy extraction on spatial patterns of suspended sediment. A Sabatino, M Heath, D McKee, C McCaig (University of Strathclyde)
Modelling biological change as a consequence of energy extraction Bell, M.C., Burrows, M.T., Waldman, S., Baston, S., Nemalidinne, R., Maciver, R., O’Hara Murray, R., Venugopal, V. & Side, J. (Heriot-Watt
University, University of the Highlands and Islands, Edinburgh University and Marine Scotland Science)
Towards an understanding of significant alterations in the hydrographic regime Lead Author: I Davies (Marine Scotland Science)
Summary of TeraWatt conclusions of relevance to the governance of marine energy
development Authors ALL – Lead Author J Side (Heriot-Watt University)
Contains headline
findings for
regulatory authorities
and industry
consenting activities,
demonstrating the
application of the
“toolbox”
methodologies
SuperGen UK Centre for Marine Energy Research
EcoWatt2050 – Ecological responses to very
large scale energy removal against a
background of climate change
UKCMER
UKCMER
ECOWATT2050 ~ START DATE 1st MARCH 2014
In response also to questions posed by the regulator:-
1. The role of marine spatial planning for very large scale
array deployments.
2. Criteria to determine the ecological limits for very
large scale energy extraction.
3. How to differentiate the effects of climate change
from energy extraction?
4. How might very large scale array deployments
ameliorate or exacerbate climate change effects?
OR: How can marine planning and policy
maximise the potential marine
renewables extraction while minimising
environmental impacts and ensuring that
these meet the requirements of European
law.
ECOWATT2050 ~ June 2014 Workshop, joined by LINC
Major output from June Meeting – clarity on individual deliverables and timescales!
ECOWATT2050 ~ Additional modelling approaches
• Use of
FVCOM,
particularly
for climate
change
models
• Scottish
Shelf model
and PFOW
CTD validation
SST
comparison
ECOWATT2050 ~ Additional modelling approaches
7km MRCS (NEMO –ERSEM-SPM)
• Use of NEMO ERSEM coupling for ecological
models
MSS Pentland Firth and Orkney Waters
(PFOW) regional scale FVCOM model
400 (20m diameter) turbines in 157 elements
Average cell length in inner sound ~ 250 m
Momentum sink parameterisation in 8th sigma
layer ~ 12 m off the bed
ECOWATT2050 ~ Additional modelling approaches
Inner sound 400 x 20 m diameter tidal
turbines in MSS FVCOM model
ECOWATT2050 ~ Additional modelling approaches
Inner sound 400 x 20 m diameter tidal
turbines in MSS FVCOM model
ECOWATT2050 ~ Additional modelling approaches
Generic Oyster type WEC Modelling Particulars
ECOWATT2050 ~ Additional modelling approaches
Use of WAMIT for
very large scale
arrays
Five WECs, Wave Direction: Oblique sea(30deg), Hs=3m, Tp=10s
ECOWATT2050 ~ Additional modelling approaches
Oyster type arrangements in OrkneySource: Marine Scotland
ECOWATT2050 ~ Additional modelling approaches
Wave height change - statistical mean difference
WITH THANKS TO: HWU (Susana Baston, Mike Bell, Simon Waldman, David Woolf, Rob Hiley, Rob
Harris), MSS (Ian Davies, Rory O’Hara Murray, Alejandro Gallego), UoE (Venki Venugopal, Manasa
Behera, Reddy Tirumaleswara Nemalidinne), Strathclyde (Mike Heath, Chric McCaig, Alessandro
Sabatino), Swansea (Harshinie Karunarathna, Ian Fairley, Antonia Chatzirodou), UHI (Arne Vögler
[LCC], Ruairi Maciver [LCC], James Morrison [LCC], Mike Burrows [SAMS]), NOCL Judith Wolf and
Hannah Buckland, Aberdeen Beth Scott and MASTS (Mark James).
PUBLICATIONS FROM ECOWATT2050
Bricheno L, Wolf J and Aldridge J (2015). Distribution of natural disturbance due to wave and tidal bed currents around
the UK. Continental Shelf Research, pp 67-77
O’Hara Murray R, Price D and Gallego A (2015). A look to the future: maximizing the sustainable tidal stream energy
potential of the Pentland Firth. MASTS Annual Science Meeting, 30 Sep – 2 Oct 2015
Side J, Harris R, Woolf D, Bell M and Brooks A (2013). Impacts of climate change on built structures (offshore). MCCIP
Science Review 2013, 295-301, doi:10.14465/2013. arc31.295-301
Tay Z and Venugopal V (2015). Optimisation of Spacing for Oscillating Wave Surge Converter Arrays Using Genetic
Algorithm. International Journal of Marine Energy, (in press).
Tay Z and Venugopal V (2015). Hydrodynamic Interactions of Oscillating Wave Surge Converters in an Array under
Random Sea State. Ocean Engineering, (in press).
Vögler A , Venugopal V and Armstrong D (2015). Wave Sensor Observations during a severe Storm event at a Marine
Energy Development Site. In: Proceedings of EWTEC 12th European Wave and Tidal Energy Conference.
Nantes, France, 6-11 September 2015.
Vögler A and Venugopal V (2015). Observations on Shallow Water Wave Distributions at an Ocean Energy Site. In:
Proceedings of the ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering,
OMAE 2015-41044.
Woolf D and Wolf J (2013) Impacts of climate change on storms and waves, MCCIP Science Review 2013, 20-26,
doi:10.14465/2013.arc03.020-026
Yates, N., Walkington, I.A., Burrows, R. and Wolf, J. (2013) Appraising the Extractable Tidal Energy Resource of the
UK’s Western Coastal Waters. Phil Trans R Soc A, 371, 20120181.