Environmental Impacts of Tidal Technologies Morgan Parry Head of WWF CymruWales

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Environmental Impacts of Tidal TechnologiesMorga
n ParryHead of WWF Cymru/Wales
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(No Transcript)
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Global temperature trends
Data IPCC
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from Stern Report
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Predicted sea temperature rise
2020s
2050s
2080s
High Emission scenario, produced by Tyndall and
Hadley Centres for UKCIP
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Past and Predicted Variability in Ocean pH
Past (from Pearson and Palmer, 2000) and
predicted (from Turley et al. 2005) variability
of marine pH. Future predictions are model
derived values based on IPCC mean scenarios. The
error bars indicate the likely seasonal scale
variability in pH.
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Zooplankton
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Trophic cascade and mismatch
Space
Phyto- plankton
Zoo- plankton
fish
birds
Time
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Simplified Food Web for the NW Atlantic
www.fishertcrisis.com/coral.html
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Electricity supply mix
Source DTI Energy Review Consultation Document
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Marine in the renewables mix
Source Oxera modeling for DTI Renewables
Innovation Review, 2003
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Modular devices
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Tidal fence
Tidal lagoon
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La Rance tidal barrage, Brittany
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Tidal lagoon design
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Emissions and Materials Consumption

• Cradle to grave assessment required
• Tidal Stream Energy devices shorter construction
  time, pay back quicker. Steel in construction
  is energy intensive but less aggregate and
  concrete
• Tidal Lagoons very high aggregate demand but
  little ancillary infrastructure
• Tidal Barrages large material requirement,
  transport and ancillary infrastructure e.g.
  roads, port facilities long pay-back time

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Species and Habitat Impacts

• Tidal Stream Energy devices environmental
  appraisals currently being carried out on
  individual devices. Fish and mammals may avoid
  them, acoustic deterrence possible
• Tidal Fences greater obstacle to fish and
  mammals than individual devices, but not complete
  barrier like barrage
• Tidal Lagoons fish and mammals may avoid the
  area but risk of fish entrapment during flood
  generation
• Tidal Barrages reduce tidal range creating a
  loss of habitats. Water quality reduced if
  dispersal/dilution inadequate. Barrier to fish
  movements

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Sediment Flow

• Tidal Stream Energy devices current turbines
  currently being modelled in Strangford Lough and
  elsewhere
• Tidal Fences considerable reduction in energy of
  water column but less than barrage
• Tidal lagoons currents and wave patterns
  altered. Choice of location can reduce
  sedimentation in shipping channels
• Tidal barrage highly modified sediment regime
  and nutrient flux upstream and downstream.
  Navigation impacts

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also.......

• implications for flood risk management
• visual impacts
• socio-economic impacts

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Severn barrage proposal
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La Rance tidal barrage, Brittany
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Annapolis Royal tidal barrage, Canada
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Bay of Fundy, Canada
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Bay of Fundy Annapolis Royal Tidal generator

• Fish passage studies using tagged fish have shown
  a mortality rate of 10-70
• Slow but steady shoreline erosion downstream
• Modelling for bigger barrage suggested that
  backed-up tide would have caused sea level in
  Boston to rise by six inches

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Severn barrage proposal
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The view of the statutory agencies

• The Severn Estuary is an internationally
  important habitat with unique ecology
• Nature and scale of barrage proposals would cause
  irreversible impacts to features, species and
  habitats of international importance
• Direct impact on Severn Estuary Special
  Protection Area (SPA), proposed Special Area of
  Conservation (pSAC), and the rivers Wye and Usk
  SACs
• A Severn Barrage development would not be
  possible within the current legal framework
  provided by the EU Habitats and Birds Directives
• Cannot envisage how required compensatory habitat
  could be provided to replace those that would be
  lost
• The case for a barrage is being promoted without
  proper consideration of other, potentially less
  environmentally damaging options
• Water quality would be affected as a direct
  result of the barrage (through the) modification
  of the sediment regime (and) nutrient flux
• 
  English Nature, Countryside Council for Wales,
  Environment Agency 2006

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The view of the statutory agencies (2)

• Barrage would fundamentally alter the basis for
  determining appropriate limits for discharges to
  and abstractions from the estuary and the rivers
  that feed into it
• Existing defences and new strategies in
  preparation will manage the flooding impacts of
  climate change without a barrage
• May be a downstream increase in vulnerability to
  tidal and storm surge flooding and consequent
  erosion caused by reflected tidal waves at the
  barrage face
• Major environmental impacts due to the vast
  amounts of materials required
• Substantial ancillary and infrastructure
  development including the need to modify or build
  new port facilities
• Difficult to envisage how the proposal would fit
  with the requirements of the Water Framework
  Directive, e.g. requirement to aim to meet good
  status by 2015
• A major programme of predictive environmental
  studies will be needed, (taking) several years to
  complete
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  English Nature, Countryside Council
  for Wales, Environment Agency 2006

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Infrastructure development

• Severn barrage is only partly about energy
  generation
• Will urbanise, industrialise and commercialise
  the land around the estuary
• New roads and airports, marinas, housing
  developments and business parks may stimulate
  job-creation, inward investment and increased
  land values
• BUT will increase dramatically the ecological
  footprint of south east Wales and SW England
• Will add significantly to our CO2 emissions,
  since unlikely that it can be achieved in a
  carbon-neutral way
• Lets have a public debate about economic growth!

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Increasing supply or reducing demand ?

• Will projects like the barrage be seen as big
  hits to fill the energy gap?
• Associated infrastructure will then claim to be
  "supplied" by green energy rather than reducing
  CO2 emissions overall
• Will it suck in investment that should go to new
  technologies?
• Will it make efficiency measures and
  decentralised supply less likely?

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Millennium Ecosystem Assessment 2005

• Mapped out the engineered future represented by
  the barrage along with a number of other possible
  scenarios
• Many ecosystem services have been degraded by
  actions taken to increase the supply of other
  services, such as energy
• Trade-offs often shift the costs of degradation
  from one group of people to another, or defer
  costs to future generations
• Benefits reaped from our engineering of the
  planet have been achieved by running down natural
  capital assets
• The overall efficiency of our economy increases,
  but it is shadowed by the risks inherent in
  large-scale human-made solutions and rigid
  control of ecosystems
• Technology sometimes creates new problems and
  vulnerabilities problems seem to emerge faster
  than solutions
• Costs of managing the environment are continually
  rising, and environmental breakdowns that affect
  large numbers of people become more common

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Sustainable Development Commission Review

• Timing
• October 2006 recruit assistant and begin scoping
• October/November prepare tender material and
  send to invited list
• November let contracts
• January/February 2007 research completed,
  publish immediately(?)
• March-June publish SDC report
• Scope of research
• UK tidal resource assessment resource mapping,
  electricity contribution, grid constraints
• Technology assessment advantages and
  disadvantages, economics, embedded emissions
• Case study 1 - Severn Barrage proposals
• Case study 2 - Severn non-barrage proposals
• Case studies 3-4 tidal flow and small-scale
  barrage options around the UK
• Outputs
• evidence-based reports by consultants
  (fact-based, no recommendations)
• SDC-produced report on tidal power with
  recommendations
• SDC-produced booklet summarising the report

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Sustainable Development Commissionoliver.knight_at_
sd-commission.org.uk mailtotidal_power_uk-subsc
ribe_at_yahoogroups.co.ukwww.sd-commission.org.uk
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In conclusion

• Welcome this conference, improving the
  information flow between scientists, politicians
  and local authorities
• Climate change an urgent economic, social and
  environmental imperative
• WWF believes energy efficiency should be tackled
  first
• Smaller scale modular renewable technologies next
• Support the review of marine renewable energy
  being carried out by SDC
• Renewable energy should be looked at in the wider
  context of sustainable development

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www.wwf.org.uk"Turning the Tide"www.wwf.org.uk
/cymru