Performance review of first full- scale AdBm system An alternative - - PowerPoint PPT Presentation

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Performance review of first full- scale AdBm system An alternative - - PowerPoint PPT Presentation

Aug 13, 2022 685 likes •854 views

Performance review of first full- scale AdBm system An alternative noise mitigation system in the face of increasingly challenging underwater noise legislation Presentation structure Contents Introduction to offshore wind

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SLIDE 1

Performance review of first full- scale AdBm system

An alternative noise mitigation system in the face of increasingly challenging underwater noise legislation

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SLIDE 2
  • Introduction to offshore wind
  • Environmental concerns
  • Environmental legislation
  • The necessity for mitigation
  • Introduction of Underwater Noise Abatement System project
  • AdBm system
  • Test set up
  • Results
  • Discussion

Presentation structure

2

Contents

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SLIDE 3
  • EU target 20% renewable energy production by

2020

  • EU target 32% renewable energy production by

2030

  • Global push towards alternative energy such as
  • ffshore wind
  • Increase in total generated MW as well as

generated MW per turbine

  • Increasing monopile diameters
  • Increasing driving forces to reach target penetration

depth

Introduction to offshore wind

3

General Trends and Characteristics

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SLIDE 4

Piling options

  • Vibratory piling
  • Impact piling
  • Alternative piling methods

All with pros and cons Future non piling alternatives such as suction buckets

  • r floating foundations

Most common method: impact piling

Foundation securing techniques

4

Pile driving overview

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SLIDE 5

Marine fauna makes use of auditory mechanisms for navigation and foraging Amplitude of piling noise can directly impact mammals in the area Piling without noise mitigation increases the range at which potential mammal impact can occur

Environmental concerns

5

Underwater sound mechanisms

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SLIDE 6
  • Varies strongly dependent on governmental philosophy (i.e. impact on individual, exclusion zone of impact)
  • No ‘one size fits all’ mitigation

Environmental legislation

6

Country Indicator Limit Additional Measures Comments Germany SEL05 (5% exceedance level) Lp,pk 160 dB re 1 μPa2s at 750 m 190 dB re 1 μPa at 750 m Maximum piling time of 3 hours; Acoustic Deterrent Device (ADD) Netherlands SEL1 (maximum sound exposure level

  • f a single strike in the

entire piling sequence) 159–172 dB 1 re 1 μPa2s at 750 m Acoustic Deterrent Device (ADD) Sound limits are driven by season as well as total number

  • f monopiles installed and can

vary per the wind farm site. Belgium Lp,pk 185 dB re 1 μPa at 750 m Acoustic Deterrent Device (ADD) United Kingdom Soft start of piling, Acoustic Deterrent Device (ADD); Marine Mammal Observers (MMO) Denmark SELcum 190 dB re 1 μPa2s at > 1300 m Acoustic Deterrent Device (ADD) Cumulatively unweighted sound limit modelled over an increasing distance starting at 1300 m United States

  • Varies by project

Must comply with Marine Mammal Protection Act, Endangered Species Act, and other possible federal, state and local legislation Usually marine mammal

  • bservers are used, and often

some noise limits set at a particular distance are in place

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SLIDE 7
  • Increasing number of countries enforcing underwater noise limits
  • Increasing challenges to meet new and existing underwater noise

limits for several reasons:

  • Increasing monopile diameters
  • Increasing driving forces required to reach desired penetration

depth

  • Lack of accurate applied knowledge regarding core drivers of

underwater noise (other than monopile diameter and driving force) such as bathymetric impacts, soil type and layer thickness impacts

Environmental legislation

7

Legislation and challenges

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SLIDE 8
  • Acoustic deterrent devices to deter mammals (e.g.

FaunaGuard, pingers, seal scarers)

  • Reduction at source (e.g. lowering driving force,

reducer units)

  • Near to pile system (e.g. AdBm, HSD, IHC NMS
  • thers)
  • Far from pile systems (e.g. Single or Double Big

Bubble Curtains)

The necessity for mitigation

8

Possible noise mitigation strategy

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SLIDE 9

UNAS Program; Dutch Government RVO program dedicated to test promising AdBm system at full-scale within a field setting. Van Oord

  • Dredging
  • Offshore Oil and Gas
  • Offshore Wind

AdBm Technologies

  • Creator of novel noise mitigation system (NMS)

TNO Netherlands Organisation for Applied Scientific Research

  • Front runner in applied science research
  • Experts in the field of underwater sound

Introduction to UNAS project

9

Underwater Noise Abatement System partnership

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SLIDE 10
  • Helmholtz resonators, tuned to 100 Hz
  • Resonators moulded in slats
  • Open system, resonator panels lowered in a

Venetian blind formation around monopile foundation

  • Passive system, no continuous power supply

necessary

AdBm system

10

Core specifications

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SLIDE 11

Tests executed according to ‘direct’ test methodology Endeavour for scientifically sound comparison. Executed on 5 piles

  • First 3 piles at 1.0m vertical slat space
  • Last 2 piles at 0.67m vertical slat space

8m of consistent soil properties Constant driving energy and pile diameter Four scenarios:

  • Scenario 1 – Benchmark test: no noise mitigation
  • Scenario 2 – AbBm: AbBm only
  • Scenario 3 – AbBm & BBC: Both AbBm & BBC system active
  • Scenario 4 – BBC system active

Test set up

12

Scenario configuration

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SLIDE 12
  • Measured according to DIN SPEC 456532017-04 standard
  • Four cardinal directions at 750 and 1500m
  • Each measurement location features two hydrophones:
  • ne hydrophone 2–3 m above the seabed
  • ne hydrophone at 10 m above the seabed

Test set up

13

Measurement set up

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SLIDE 13
  • Reduction of 5 dB SEL and 6 dB Lpeak with the
  • riginal 1.0m slat spacing
  • Reduction of 11 dB SEL and 12 dB Lpeak with the
  • riginal 1.0m slat spacing in combination with

SBBC

  • Reduction of 7 dB SEL and Lpeak with the

reduced 0.67m slat spacing

  • Reduction of 15 dB SEL and 18 dB Lpeak with

the original 1.0m slat spacing in combination with SBBC

  • Clear increase in performance due to slat

reduction due to increased void fraction in water column

  • All reductions refer to 750m

Results

14

Broadband analysis

Test phase Test Scenario Slat spacing Effective noise reduction of the SEL [dB] Effective noise reduction of the Lp,pk [dB] 1 AdBm 1.00 m 5 ≤ 5 ≤ 6 5 ≤ 6 ≤ 6 AdBm + BBC 10 ≤ 11 ≤ 11 12 ≤ 12 ≤ 13 BBC 7 ≤ 8 ≤ 8 9 ≤ 9 ≤ 10 2 AdBm 0.67 m 7 ≤ 7 ≤ 8 7 ≤ 7 ≤ 8 AdBm + BBC 14 ≤ 15 ≤ 15 18 ≤ 18 ≤ 20 BBC 10 ≤ 10 ≤ 11 12 ≤ 13 ≤ 15

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SLIDE 14

Satisfying first result of first full-scale field tests AdBm Versatile system with many readily implementable potential improvements

  • Increasing number of slats, either radially or vertically
  • Manual filling of resonators by near-pile bubble curtain
  • Integration with a near-pile bubble curtain

Very robust system from an operational perspective Very high potential to be deployed at future Van Oord offshore wind projects Potential for identification of ‘problem’ frequencies for predetermined sensitive receivers to cater for more effective mitigation rather than broadband

Discussion

16

UNAS Overview

without resonators

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SLIDE 15

FaunaGuard future developments (video)

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SLIDE 16

Thank you for your time! Questions?

Questions?

19