ecological significance of electromagnetic fields generated by the offshore wind industry ewec,...

Ecological Significance of Electromagnetic Fields Generated by

the Offshore Wind Industry

EWEC, Athens

2nd March 2006

Ian Gloyne-Phillips, CMACS Ltd;

Andrew Gill, Cranfield University; Yi Huang, Liverpool University

EWEC March 2006

Overview of Presentation

• Electromagnetic Field (EMF) generation

EWEC March 2006

Overview of Presentation

• Electromagnetic Field (EMF) generation

• Why EMF is an environmental concern

EWEC March 2006

Overview of Presentation

• Electromagnetic Field (EMF) generation

• Why EMF is an environmental concern

• What we are doing to address this issue

EWEC March 2006

EMF Generation

Typical Submarine Power Cable

EWEC March 2006

Electric Field (E field)

Magnetic Field (B field)

Induced Electrical Field

(iE field)

the E field will be retained within industry-standard cables

the B field is detectable outside the cable...

...and induces a second electric field outside the cable

Electromagnetic Field (EM field)

EMF Generation

EWEC March 2006

Why is EMF a concern?

EWEC March 2006

Because certain marine organisms may be able to

detect electromagnetic fields from submarine power cables

or offshore substations

EWEC March 2006

EMF Detection by Marine Organisms

• Electric field sensitivity

• specialised electroreceptors (elasmobranchs)

EWEC March 2006

EMF Detection by Marine Organisms

• Electric field sensitivity

• detection of voltage gradients (jawless fish and some bony fish)

EWEC March 2006

EMF Detection by Marine Organisms

• Magnetic field sensitivity

• induced electric field detection

(elasmobranchs and some bony fish)

EWEC March 2006

EMF Detection by Marine Organisms

• Magnetic field sensitivity

• magnetite based detection

(e.g. salmonids, Cetacea, Chelonia)

EWEC March 2006

Evidence of EMF detection

• Experimental studies

• adult behaviour, egg/larval development

• Observational evidence

• sharks biting cables

• apparent reactions to power cables

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Potential Impacts of EMF

• Affect orientation

• Disruption of migrations

• Attraction/repulsion of animals

• Egg/larval development impacts

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Potential Impacts of EMF

• Particular concern for elasmobranchs

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Potential Impacts of EMF

BUT it is uncertain:

1. if 50 Hz fields of a magnitude produced by submarine power cables are detected

2. if so, whether there is any adverse impact

EWEC March 2006

…EMF is an issue for the offshore renewables industry because as a potential environmental impact it is a matter of concern to environmental regulators…

EWEC March 2006

…and can therefore affect the consenting of offshore developments…

EWEC March 2006

So What are We Doing?

• Improving understanding– EMF modelling– Experimental studies with animals

• Field measurements of EMF

• Monitoring existing offshore wind farms

• Planning comprehensive research

• Negotiating with regulators

EWEC March 2006

Example Model Scenario(current density)

Cable x-section (internal) Cable x-section (external)

Sea bed

20m

1m

Cable x-section (internal) Cable x-section (external)

Sea bed

20m

1m

internal E field induced E field

EWEC March 2006

Key Outputs of Modelling

• Magnetic fields up to 1.6 µT (micro Tesla)NB the geomagnetic field is c. 50 µT

EWEC March 2006

Key Outputs of Modelling

• Magnetic fields up to 1.6 µT (micro Tesla)– cf the geomagnetic field (c. 50 µT)

• iE fields of tens of µV/m (micro Volts/m)– Modelled range 2.5 – 91 µV/m

EWEC March 2006

Key Outputs of Modelling

• Magnetic fields up to 1.6 µT (micro Tesla)– cf the geomagnetic field (c. 50 µT)

• iE fields of tens of µV/m (micro Volts/m)– modelled range 2.5 – 91 µV/m– within the range which may be attractive to

sharks, skates and rays (elasmobranchs)

EWEC March 2006

Experimental Studies

S a l t b r i d g e e l e c t r o d e

E l e c t r i c c i r c u i t

S a l t b r i d g e e l e c t r o d e

E l e c t r i c c i r c u i t

EWEC March 2006

Field Measurements of EMF

• Portable E and B field probes

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Field Measurements of EMF

0

10

20

30

40

50

60

70

80

90

0 10 20 30 40 50 60 70 80

distance from start (m)

EM

F (

uV

/m)

import/export cables

EWEC March 2006

Field Measurements of EMF

• Field measurements have supported modelling results

EWEC March 2006 Photo courtesy Npower Renewables

Monitoring Wind Farms

EWEC March 2006

Monitoring Wind Farms

• Fishing surveys

• results of current programmes are unclear in terms of EMF

EWEC March 2006

Future Investigations

• Further laboratory work

EWEC March 2006

Future Investigations

• Further laboratory work

• Mesocosm study– control EMF and track fish within a large

experimental enclosure

EWEC March 2006

Future Investigations

• Further laboratory work

• Mesocosm study

• Large scale tracking study

EWEC March 2006

The Consultant’s Dilemma

…there are grounds for concern but a lack of good evidence and developers want certainty

EWEC March 2006

How we can proceed now

• Get some answers– requires industry and regulator support

EWEC March 2006

How we can proceed now

• Get some answers– requires industry and regulator support

• Adaptive management– pragmatic progression of developments

EWEC March 2006

How we can proceed now

• Get some answers– requires industry and regulator support

• Adaptive management– pragmatic progression of developments

• React to knowledge as we gain it

EWEC March 2006

Thank you..

• Contact details

ian@cmacsltd.co.uk

www.cmacsltd.co.uk