IEC TS 62600-40:2019

Marine energy - Wave, tidal and other water current converters - Part 40: Acoustic characterization of marine energy converters

IEC TS 62600-40:2019 provides uniform methodologies to consistently characterize the sound produced by the operation of marine energy converters that generate electricity, including wave, current, and ocean thermal energy conversion. This document does not include the characterization of sound associated with installation, maintenance, or decommissioning of these converters, nor does it establish thresholds for determining environmental impacts. Characterization refers to received levels of sound at particular ranges, depths, and orientations to a marine energy converter.
The scope of this document encompasses methods and instrumentation to characterize sound near marine energy converters, as well as the presentation of this information for use by regulatory agencies, industry, and researchers. Guidance is given for instrumentation calibration, deployment methods around specific types of marine energy converters, analysis procedures, and reporting requirements.
This document is applicable to characterization of sound from individual converters and arrays. This document primarily describes measurement procedures for individual converters, with extension to arrays discussed in informative Annex.

General Information

• Status: Published
• Publication Date: 17-Jun-2019
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 27.140 - Hydraulic energy engineering
• Technical Committee: TC 114 - Marine energy - Wave, tidal and other water current converters
• Current Stage: PPUB - Publication issued
• Completion Date: 18-Jun-2019

Standards Content (sample)

IEC TS 62600-40
Edition 1.0 2019-06
TECHNICAL
SPECIFICATION
colour
inside
Marine energy – Wave, tidal and other water current converters –
Part 40: Acoustic characterization of marine energy converters
IEC TS 62600-40:2019-06(en)
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IEC TS 62600-40
Edition 1.0 2019-06
TECHNICAL
SPECIFICATION
colour
inside
Marine energy – Wave, tidal and other water current converters –
Part 40: Acoustic characterization of marine energy converters
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.140 ISBN 978-2-8322-6926-8

Warning! Make sure that you obtained this publication from an authorized distributor.

® Registered trademark of the International Electrotechnical Commission
---------------------- Page: 3 ----------------------
– 2 – IEC TS 62600-40:2019 © IEC 2019
CONTENTS

FOREWORD ........................................................................................................................... 5

INTRODUCTION ..................................................................................................................... 7

1 Scope .............................................................................................................................. 8

2 Normative references ...................................................................................................... 8

3 Terms and definitions ...................................................................................................... 9

4 Symbols and abbreviated terms ..................................................................................... 11

5 Outline of method .......................................................................................................... 11

6 Instrumentation .............................................................................................................. 12

6.1 Sound measurement system ................................................................................. 12

6.1.1 General ......................................................................................................... 12

6.1.2 Frequency range ........................................................................................... 13

6.1.3 Sensitivity and dynamic range ....................................................................... 13

6.1.4 Hydrophone directionality .............................................................................. 13

6.1.5 Data acquisition and playback system ........................................................... 13

6.1.6 Calibration ..................................................................................................... 13

6.2 Deployment platforms for sound measurement systems ........................................ 14

6.2.1 Fixed platforms .............................................................................................. 14

6.2.2 Drifting platforms ........................................................................................... 14

6.2.3 Flow-noise and self-noise minimization .......................................................... 16

6.3 Contextual measurements ..................................................................................... 16

6.3.1 General ......................................................................................................... 16

6.3.2 Winds ............................................................................................................ 16

6.3.3 Waves ........................................................................................................... 17

6.3.4 Currents ........................................................................................................ 17

6.3.5 Sound speed profiles ..................................................................................... 18

6.3.6 Marine energy converter output ..................................................................... 18

7 Measurements and measurement procedures ................................................................ 19

7.1 Metocean conditions ............................................................................................. 19

7.1.1 General ......................................................................................................... 19

7.1.2 Winds ............................................................................................................ 19

7.1.3 Waves ........................................................................................................... 19

7.1.4 Currents ........................................................................................................ 19

7.2 Potential sources of acoustic masking ................................................................... 19

7.2.1 General ......................................................................................................... 19

7.2.2 Vessel noise .................................................................................................. 20

7.2.3 Biological noise sources ................................................................................ 20

7.2.4 Precipitation .................................................................................................. 20

7.2.5 Air traffic ........................................................................................................ 20

7.2.6 Physical sources............................................................................................ 20

7.3 Underwater sound from marine energy converters ................................................ 20

7.3.1 Levels of characterization .............................................................................. 20

7.3.2 Measurement frequency range....................................................................... 20

7.4 Wave energy converters ....................................................................................... 21

7.4.1 WEC characteristics ...................................................................................... 21

7.4.2 Sound measurement system deployment ....................................................... 22

7.4.3 Temporal resolution ....................................................................................... 22

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IEC TS 62600-40:2019 © IEC 2019 – 3 –

7.4.4 Spatial resolution ........................................................................................... 22

7.4.5 Sound speed profiles ..................................................................................... 23

7.5 Current energy converters .................................................................................... 23

7.5.1 CEC characteristics ....................................................................................... 23

7.5.2 Sound measurement system deployment ....................................................... 23

7.5.3 Temporal resolution ....................................................................................... 24

7.5.4 Spatial resolution ........................................................................................... 24

7.5.5 Sound speed profiles ..................................................................................... 25

7.6 Ocean thermal energy converters ......................................................................... 25

7.6.1 Overview ....................................................................................................... 25

7.6.2 Sound measurement system deployment ....................................................... 26

7.6.3 Temporal resolution ....................................................................................... 26

7.6.4 Spatial resolution ........................................................................................... 26

7.6.5 Sound speed profiles ..................................................................................... 27

8 Data analysis procedures .............................................................................................. 27

8.1 General ................................................................................................................. 27

8.2 Metocean conditions ............................................................................................. 27

8.2.1 Winds ............................................................................................................ 27

8.2.2 Waves ........................................................................................................... 28

8.2.3 Currents ........................................................................................................ 28

8.3 Sound speed profiles ............................................................................................ 28

8.4 Marine energy converter output............................................................................. 28

8.4.1 General ......................................................................................................... 28

8.4.2 Wave energy converters ................................................................................ 28

8.4.3 Current energy converters ............................................................................. 28

8.4.4 Ocean thermal energy converters .................................................................. 28

8.5 Underwater sound ................................................................................................. 29

8.5.1 General ......................................................................................................... 29

8.5.2 Acoustic signal processing............................................................................. 29

8.5.3 Geo-referencing of drifting acoustic measurements ....................................... 30

8.5.4 Global sample acceptance criteria ................................................................. 30

8.5.5 Considerations specific to wave energy converters ........................................ 31

8.5.6 Considerations specific to current energy converters ..................................... 32

8.5.7 Considerations specific to ocean thermal energy converters .......................... 32

8.5.8 Aggregate statistics ....................................................................................... 33

9 Information to be reported ............................................................................................. 33

9.1 Sound measurement system ................................................................................. 33

9.2 Marine energy conversion system ......................................................................... 34

9.3 Measurement site ................................................................................................. 34

9.4 Contextual measurements ..................................................................................... 34

9.5 Specific reporting for wave energy converters ....................................................... 35

9.5.1 Level A .......................................................................................................... 35

9.5.2 Level B .......................................................................................................... 37

9.6 Specific reporting for current energy converters .................................................... 37

9.6.1 Level A .......................................................................................................... 37

9.6.2 Level B .......................................................................................................... 37

9.7 Specific reporting for ocean thermal energy converters ......................................... 37

9.7.1 Level A .......................................................................................................... 37

9.7.2 Level B .......................................................................................................... 38

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– 4 – IEC TS 62600-40:2019 © IEC 2019

Annex A (informative) Sound within and around arrays ....................................................... 39

Annex B (informative) Additional measurements for source level estimation ........................ 40

Annex C (informative) Approaches to minimizing flow-noise ................................................. 41

C.1 General ................................................................................................................. 41

C.2 Methods specific to measurements in waves ......................................................... 41

C.3 Methods specific to measurements in currents ...................................................... 41

C.4 General methods .................................................................................................. 42

C.5 Methods to mitigate flow-noise distortion .............................................................. 42

Annex D (informative) Approaches to minimizing self-noise ................................................. 43

Bibliography .......................................................................................................................... 44

Figure 1 – Hydrophone orientation relative to WEC ............................................................... 23

Figure 2 – Zones for drifting CEC measurements .................................................................. 25

Figure 3 – Zones for drifting OTEC measurements ................................................................ 27

Figure 4 – Example grid of median MEC sound pressure levels as a function of

significant wave height and energy period ............................................................................. 35

Shaded region denotes interquartile range. ........................................................................... 36

Figure 5 – Example of median mean-square sound pressure spectral density level

variations as a function of sea state for a single spatial position ........................................... 36

Figure 6 – Example of median decidecade sound pressure level variations as a

function of sea state for a single spatial position ................................................................... 36

Table 1 – Summary of measurement procedures .................................................................. 12

Table 2 – Minimum measurement grades for metocean observations by category of

marine energy converter ....................................................................................................... 16

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IEC TS 62600-40:2019 © IEC 2019 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MARINE ENERGY – WAVE, TIDAL AND
OTHER WATER CURRENT CONVERTERS –
Part 40: Acoustic characterization of marine energy converters
FOREWORD

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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

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• the subject is still under technical development or where, for any other reason, there is the

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Technical specifications are subject to review within three years of publication to decide

whether they can be transformed into International Standards.

IEC TS 62600-40, which is a Technical Specification, has been prepared by IEC technical

committee 114: Marine energy – Wave, tidal and other water current converters.
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– 6 – IEC TS 62600-40:2019 © IEC 2019
The text of this Technical Specifications based on the following documents:
Draft TS Report on voting
114/297/DTS 114/307/RVDTS

Full information on the voting for the approval of this technical specification can be found in

the report on voting indicated in the above table.

This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts in the IEC 62600 series, published under the general title Marine energy –

Wave, tidal and other water current converters, can be found on the IEC website.

This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to

the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it

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contains colours which are considered to be useful for the
contents. Users should therefore print this document using a colour printer.
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IEC TS 62600-40:2019 © IEC 2019 – 7 –
INTRODUCTION

The purpose of this document is to provide uniform methodologies that will ensure

consistency and accuracy in the measurement and analysis of acoustical emissions from

marine energy converters. These systems include wave, current (tidal, ocean, and river), and

ocean thermal energy conversion. The document provides guidance on the measurement,

analysis, and reporting of acoustic emissions from marine energy converters and has been

prepared with the anticipation that it would be applied by:

• Marine energy converter manufacturers striving to meet well-defined acoustic emission

performance requirements and/or a possible declaration system;

• Purchasers of marine energy converters to specify such performance requirements;

• Operators of marine energy converters who may be required to verify that stated, or

required, acoustic performance specifications are met for new or refurbished units;

• Operators of marine energy test sites, who may be required to assess conformity with

consented acoustic levels at their sites;

• Marine energy converter planners or regulators who must be able to accurately and fairly

define acoustical emission characteristics of marine energy converters in response to

environmental regulations or permit requirements for new or modified installations.

The methods and reporting requirements in this document ensure that continuing

development and operation of marine energy converters is carried out in an atmosphere of

consistent and accurate communication relative to environmental concerns.
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– 8 – IEC TS 62600-40:2019 © IEC 2019
MARINE ENERGY – WAVE, TIDAL AND
OTHER WATER CURRENT CONVERTERS –
Part 40: Acoustic characterization of marine energy converters
1 Scope

This part of IEC 62600 provides uniform methodologies to consistently characterize the sound

produced by the operation of marine energy converters that generate electricity, including

wave, current, and ocean thermal energy conversion. This document does not include the

characterization of sound associated with installation, maintenance, or decommissioning of

these converters, nor does it establish thresholds for determining environmental impacts.

Characterization refers to received levels of sound at particular ranges, depths, and

orientations to a marine energy converter. Informative Annex B provides guidance on

additional measurements that would be necessary to estimate source levels.

The scope of this document encompasses methods and instrumentation to characterize sound

near marine energy converters, as well as the presentation of this information for use by

regulatory agencies, industry, and researchers. Guidance is given for instrumentation

calibration, deployment methods around specific types of marine energy converters, analysis

procedures, and reporting requirements.

This document is applicable to characterization of sound from individual converters and

arrays. This document primarily describes measurement procedures for individual converters,

with extension to arrays discussed in informative Annex A.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their

content constitutes requirements of this document. For dated references, only the edition

cited applies. For undated references, the latest edition of the referenced document (including

any amendments) applies.

IEC 60565, Underwater acoustics – Hydrophones – Calibration in the frequency range 0,01

Hz to 1 MHz

IEC 61108-4, Maritime navigation and radiocommunication equipment and systems – Global

navigation satellite systems (GNSS) – Part 4: Shipborne DGPS and DGLONASS maritime

radio beacon receiver equipment – Performance requirements, methods of testing and

required test results
IEC 61400-12-1, Wind energy generation systems – Part 12-1: Power performance
measurements of electricity producing wind turbines

IEC TS 62600-1, Marine energy – Wave, tidal and other water current converters – Part 1:

Terminology

IEC TS 62600-20, Marine energy – Wave, tidal and other water current converters – Part 20:

Design and analysis of an Ocean Thermal Energy Conversion (OTEC) plant – General
guidance

IEC TS 62600-100, Marine energy – Wave, tidal and other water current converters – Part

100: Electricity producing wave energy converters – Power performance assessment
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IEC TS 62600-40:2019 © IEC 2019 – 9 –

IEC TS 62600-200, Marine energy – Wave, tidal and other water current converters – Part

200: Electricity producing tidal energy converters – Power performance assessment

ISO 17208-1, Underwater acoustics – Quantities and procedures for description and

measurement of underwater sound from ships – Part 1: Requirements for precision
measurements in deep water used for comparison purposes
3 Terms and definitions

For the purposes of this document, the terms and definitions given in IEC TS 62600-1 and the

following apply.

ISO and IEC maintain terminological databases for use in standardization at the following

addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
acoustic self-noise

sound at a receiver caused by the deployment, operation, or recovery of the receiver, and its

associated platform
[SOURCE: ISO 18405:2016, 2.1.1.5]
3.2
ambient noise

all sound, except acoustic self-noise and sound associated with a specified signal

[SOURCE: ISO 18405:2016, 2.1.1.6, modified – Notes not relevant to this document have

been removed.]
3.3
flow-noise
non-acoustic pressure fluctuations measured by a pressure-sensitive instrument
Note 1 to entry: This is sometimes referred to as “hydrodynamic noise”.

Note 2 to entry: Moving water can also excite structures, causing them to radiate acoustic pressure, but this is

categorized as acoustic self-noise.
3.4
mean-square sound pressure spectral density

distribution as a function of frequency of the mean-square sound pressure per unit bandwidth

of a sound having a continuous spectrum

Note 1 to entry: Mean-square sound pressure spectral density is expressed in units of pascal squared per hertz

(Pa /Hz).

Note 2 to entry: For operational purposes, mean-square sound pressure spectral density is estimated as the

mean-square sound pressure in a finite frequency band divided by the frequency bandwidth. The averaging time

and frequency band shall be specified.
[SOURCE: ISO 18405: 2016, 2.1.3.13, modified
...