•12/16/2008
Ocean Energy:
Scoping the Resource
Renewable Resources Group
CB, GD, MH, KL, IM, CM, SN, NQ, MW
Solving the climate problem for the next 50
years with current technologies
Pacala and Socolow, Science, 305, 968-971, (2004)
7 wedges
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•12/16/2008
Choose 7 of 15 wedges distributed over,
for example:
• energy efficiency and conservation
• more efficient forest and land use
• injecting CO2 in the subsurface
• renewable energy and fuels
‘EU leaders claim historic agreement on
cutting pollution’
Guardian, 13th Dec 2008
‘Triple 20 deal’
• 20% reduction of 1990-level of greenhouse gases by 2020
• 20% reduction in energy consumption by same deadline
• 20% EU energy mix from renewables
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‘Delivering a Sustainable Energy Future
for Ireland : 2007-2020’
By 2020, Government aims for:
20% savings in energy demand compared to 2007
demand across all sectors with a target of ~30% to
surpass EU ambition
33% electricity generation from renewables,
including 500 MW from wave and tidal stream energy
Mostly from wind
Electricity generators
‘ESB plans to spend €22bn on
network and plants’
Irish Times, 28th March 2008
By 2020, ESB intends to
deliver 33% of electricity from
wind with 6GW onshore and
8GW offshore
EU Supergrid to integrate
generation and distribution
for grid stability
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Wind energy research
R & D focus on large wind turbines
for deployment offshore
Grid connectivity
Smart grids
Storage of energy in
batteries
Ocean energy
Pelamis wave energy converter
(European Marine Energy Centre,
Orkney)
Marine Current Turbine tidal
stream converter
(Strangford Lough)
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•12/16/2008
Preliminary assessments of ocean
energy resource
Viable tidal stream
SEI, 2007
Accessible wave
Renewable Resources Group and
Ocean Energy
• Detailed accessible resource assessment (tidal stream,
wave)
• Site bathymetry, geotechnical conditions, environmental
impact (tidal stream, wave, wind foundations & cabling)
• Local grid connectivity
• Maritime infrastructure for maintenance/assembly
• Sea space conflicts
• Legislative and socio-economic drivers
Direct observations (waves, currents, bathymetry, seabed
type) and modelling vital for accurate viable resource
assessment to encourage commercial device deployment
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•12/16/2008
Predicting wave fields
Predictive Irish Sea Models
(www.prism.ie)
Swan
M2 Buoy
6
S i g n i fi c a n t H e i g h t (m )
5
4
3
2
1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Time (Days)
Site Characterisation
• Accurate siting and current
prediction require accurate
bathymetry
• Cable-laying requires
accurate bathymetry and
preferably soft sediments
• Strong capability in swath
bathymetry mapping and
interpretation, acoustic
current measurements for
subsequent model validation
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•12/16/2008
Site Characterisation
Highresolution
bathymetry to
help siting of
in-stream tidal
energy devices
Proposed
tidal stream
array field
Prototype site
Modelling & observational oceanography
Strong capability in acquiring current data to drive subsequent modelling
Modelling to set
boundary conditions
for localised models
Modelling of
local
accelerated
currents in
Galway Bay
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•12/16/2008
Modelling flow & power for tidal turbines
Seabed Geotechnical Assessment
• Seabed type
affects foundation
design and
installation method
• Expertise in
geotechnical
quantification
Acoustic echoes contain
information on sediment
properties in each layer
Water
1st layer
2nd layer
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•12/16/2008
Seabed Geotechnical Assessment
• Seismic data for
geotechnical properties
• Parameters for strain
modelling of monopile
installations and
assessment of cable
laying routes
• Calibration with ROV based video and
sediment physical
sampling
Geotechnical modelling of monopile
(Danish Geotechnical Institute)
Seabed Geotechnical Assessment
Backscatter
and
bathymetry
• Surficial geology
possible through
innovative processing of
multibeam data
• Calibration with ROVbased video and
sediment physical
sampling
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•12/16/2008
Sediment Transport Hazards
• Mobile sand can be
hazardous for seafloor
cabling and stress
loading on device
installations
• Need to monitor sand
mobility with repeated
surveys to develop local
predictive models
colin.brown@nuigalway.ie
garret.duffy@nuigalway.ie
michael.hartnett@nuigalway.ie
Example 6 repeated multibeam
surveys over six-month period
“The difference between stumbling blocks and stepping stones
is how you use them”
•10