North Hoyle and RhylFlats Offshore Wind Farms - snh.org.uk · PDF fileRWEInnogy 7/17/2009 PAGE...

North Hoyle and Rhyl Flats

Offshore Wind Farms:

Review of good practice in monitoring,

construction and operation

Jamie May

RWE Innogy 7/17/2009 PAGE 2

RWE npower renewables (NRL)

> UK subsidiary of RWE Innogy, a pan-European renewable energy company

> Offshore wind projects operating, in development and in construction across the UK, Netherlands, Germany and Belgium.

> NRL currently owns and operates 533MW.

> Now operates 150MW of offshore wind in total.

> 7 onshore wind farms (196MW), 11 hydro stations (18MW) in Scotland,

> Further 2700MW Offshore Wind in UK development, excluding Round 3.

North Hoyle, N. Wales


Offshore Projects

Offshore Wind interests throughout the UK

Gwynt y Môr, Rhyl Flats, North Hoyle

Greater Gabbard

Inch Cape

Triton Knoll


North Hoyle: Background

> First commercial UK Offshore Wind Farm, built in 2003.

> 60MW consisting of 30 Vestas V80 2MW turbines.

> 87.4% availability (after 3rd year of operation, 2007). Improved in 2008.

> Generates enough electricity to meet the average annual needs of 40,000 homes.

> Total project capital cost of £81m, £1.35m/MW.


North Hoyle from Bryn-llwyn AONB Viewpoint 2003


North Hoyle: FEPA Key Facts

> First UK offshore wind project to complete its FEPA monitoring campaign

> 5 years of monitoring

> Studies from CEFAS, ESS, CMACS, CFCM, MarineSeen, Osiris, COWRIE

> Surveys going back to 2001

> Additional research into foundation colonisation

> Final report can be viewed and downloaded at: http://www.npower-renewables.co.uk/northhoyle/environment.asp


Key environmental assessment predications tested

by the FEPA monitoring

> Benthic ecology unaffected bar minor and localised impacts from construction which would rapidly recover.

> Extensive colonisation of the turbines will occur allowing an increase in local species diversity and productivity.

> Assumed disturbance of Red Throated Diver and Scoter at up to 2km during wind farm operation, no disruption to flight paths and no direct habitat loss.

> No significant impact on Liverpool Bay or Eastern Irish Sea Marine Mammal populations.


2m Beam Trawl Programme

> 22 sites; 2m beam; chain mat; 4mm cod end; 300m tows

> surveyed annually in August 2001 and autumn 2003-2006

> Only likely to detect changes attributable to OWF if very large.


Beam Trawl Conclusions

32 species recorded from the

trawls over 5 year period

No evidence to suggest that the

fish and epifaunal marine

communities altered when

compared to 2001 baseline

Major trends in abundance and

diversity evident across all the

monitoring sites including near-

field and far-field controls and

across all survey years appear

to be within the bounds of

natural variation.


Colonisation Surveys 2004

> Large shoals of juvenile whiting were observed around all the underwater structures studied:

> 6 monopiles studied (in place for c 1 yr)

> Turbines were operating during surveys


Colonisation Survey 2008

>Much poorer visibility

>Juvenile Cod and Plaice were observed on the seabed in proximity to turbines

>Whiting seen but unconfirmed abundance


Marine Mammals

Monthly Harbour Porpoise Sightings

0

1

2

3

4

5

6

7

8

Jan-03

Mar-03

May-03

Jul-03

Sep-03

Nov-03

Jan-04

Mar-04

May-04

Jul-04

Sep-04

Nov-04

Jan-05

Mar-05

May-05

Jul-05

Sep-05

Nov-05

Jan-06

Mar-06

May-06

Jul-06

Sep-06

Nov-06

Jan-07

Month

Number of Harbour Porpoise

Post-constructionPre-construction

During Construction

> Ad hoc sightings during environmental surveys

> Sightings largely in winter/spring.

> NB 1 data have not been standardised by effort or conditions.

> Gaps in 2005 data collection


0

100

200

300

400

500

600

700

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Month

Maximum and Average Monthly counts of Atlantic Grey

Seal

1960

1970

1980

1990

2001

2002

2003

2005

Hilbre Island Grey Seal Data Records

During

construction

Yr 1 post-

construction

First piling

events


FEPA Bird Monitoring Objectives

1. Determine if the wind farm causes a change in bird use and behaviour

2. Determine if there is a barrier effect to movement of birds through the site.

3. Determine the distribution of Common Scoter in Liverpool Bay, through

continued contribution to the aerial survey.

Supplementary conditions:

4. If Objective 3 shows change in the Common Scoter population, monitor the

benthos to determine if the change is a result of a change in food supply.

5. If Objectives 1 or 2 reveal significant use of North Hoyle by populations of

conservation concern, at heights that could incur a risk of collision, a

programme of collision risk monitoring will be implemented.


Bird Survey Limitations

Phase Boat Aerial

Pre-

Construction

3 4

Construction 11 4

Operation 33 15

> Only a few surveys were made in

the pre-construction period and

these were in winter months only.

> Boat surveys.

> -No control site (reference site).

-Transect paths not consistent.

> Aerial surveys.

- Unable to survey the wind farm

itself after construction.

- Identification to species groupings

only.


Flight height and barrier effect

<2.5m 2-5m-

20m

>20m

Auk sp. 191 27 0

Diver sp. 51 14 3

Gannet 28 121 12

Kittiwake 30 291 32

Scoter

sp.

3264 6786 2

Shag sp. 183 179 82

Tern sp. 0 26 1

> Flight directions of scoter appear

to be largely influenced by the

boat.

> Species seen flying within the wind

farm included cormorants, gulls,

terns, gannet and scoter.

> The wind farm may have had an

inhibitory effect, but it has not

been a barrier.


Ornithological Conclusions> Little statistical evidence of changes in numbers or distribution of any

species.

> No evidence of a barrier effect of the wind farm.

> Few birds of key species were seen flying at rotor blade heights

> Power of tests for changes caused by wind farm is low:

– Few pre-construction surveys.

– No control site for boat surveys.

> Inadequate baseline information implies little value in extra survey work

for this site.

> Boat survey methods are not efficient for studying movements through or

around site.


Rhyl Flats: Background

> NRLs second Round 1 project

> Originally developed by C.O.W.L. and

bought by NRL in 2002 (EIA by ERM)

> 90MW consisting of 25 Siemens 3.6MW

turbines.

> Constuction started 2007

> Nearing completion, all turbines erected,

first generation was during the summer,

full operation expected before end of

year.

> Total project cost ca. £190m


Rhyl Flats Project Area


Sole Spawning Areas: Piling restrictions

> Issue of subsea noise impacts upon sole

spawning raised by Licensing Authority

> Retrospective condition added to FEPA

Licence in 2008.

> No piling between Mar - mid May.

> NRL had identified Sole spawning

hotspots in Liverpool Bay. Negotiation

with Cefas and MFA to stage piling

activity.

> Flexible approach agreed to installation

sequence starting with southernmost

foundation positions in mid April.


Marine Mammal Observer Monitoring

> Agreed MMO methodology with CCW

with buy-in from JNCC

> Dedicated survey vessel and team

with authority over piling contractor.

> Visual + acoustic monitoring 500m

“zone of harm” to ensure the area is

devoid of marine mammals for a

period of 30 minutes prior to soft-start.

> Soft start piling ramping up SPL to full

force after 20 minutes.


Underwater Noise at 500m from piling vessel


Subsea Noise Measurement


Soft Start compared with full piling force


Rhyl Flats: Construction Timing Restriction - birds


Vessel Routing Plan: Common Scoter Avoidance


Rhyl Flats FEPA Monitoring: Positives

> Successfully extended the cable construction season into the winter by

demonstrating reduced Common Scoter numbers between Oct-Dec

> Monitoring in that period showed no impact in distribution of Scoter from

construction activity

> 30000 bird within the wind farm survey area – only a few hundred flying at rotor

height – i.e. at risk of collision.

> Successfully agreed reduced survey effort to key migration times between

October and March for SPA species Red Throated Diver and Common Scoter.

> Successfully negotiated sole spawning timing restricted with agreed flexible

approach to installation sequence.


Thank YouJamie May

Offshore Site Acquisition Manager

01793 896324

[email protected]

North Hoyle and RhylFlats Offshore Wind Farms - snh.org.uk · PDF fileRWEInnogy 7/17/2009 PAGE...

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