ISO/IEC 30134-9:2022

INTERNATIONAL ISO/IEC
STANDARD 30134-9
First edition
2022-03
Information technology — Data
centres key performance indicators —
Part 9:
Water usage effectiveness (WUE)
Technologies de l'information — Indicateurs de performance clés des
centres de données —
Partie 9: Efficacité dans l'utilisation de l'eau (WUE)
Reference number
© ISO/IEC 2022
© ISO/IEC 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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© ISO/IEC 2022 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, abbreviated terms and symbols . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 3
3.3 Symbols . 3
4 Applicable area of the data centre . 4
5 Determination of WUE .5
6 Measurement of WUE . .5
6.1 General . 5
6.2 Measuring actual water usage. 5
6.2.1 Calculation, measurement period and frequency . 5
6.2.2 Categories of WUE . 5
7 Application of WUE .8
8 Reporting of WUE . 8
8.1 Requirements . 8
8.1.1 Standard construct for communicating WUE data . 8
8.1.2 Data for public reporting of WUE . 9
8.2 Recommendations . 9
8.3 Example of reporting WUE values . 10
8.4 WUE derivatives . 10
8.4.1 Purpose of WUE derivatives . 10
8.4.2 Interim WUE . 11
8.4.3 Partial WUE . 11
8.4.4 Design WUE . 11
8.4.5 Quality WUE . 11
8.4.6 Peak WUE .12
8.5 Water reuse factor (WRF) . 12
Annex A (informative) Examples of use .13
Annex B (normative) Water siginficance .15
Annex C (informative) Energy water intensity factor .16
Annex D (normative) Land consumption .17
Bibliography .19
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© ISO/IEC 2022 – All rights reserved

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work.
The procedures used to develop this document and those intended for its further maintenance
are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria
needed for the different types of document should be noted. This document was drafted in
accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives or
www.iec.ch/members_experts/refdocs).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC
list of patent declarations received (see https://patents.iec.ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www.iso.org/iso/foreword.html. In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 39, Sustainability, IT and data centres.
A list of all parts in the ISO/IEC 30134 series can be found on the ISO and IEC websites.
Any feedback or questions on this document should be directed to the user’s national standards
body. A complete listing of these bodies can be found at www.iso.org/members.html and
www.iec.ch/national-committees.
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© ISO/IEC 2022 – All rights reserved

Introduction
The global economy is today reliant on information and communication technologies and the associated
generation, transmission, dissemination, computation and storage of digital data. All markets have
experienced exponential growth in that data, for social, educational and business sectors and while the
internet backbone carries the traffic, there are a wide variety of data centres at nodes and hubs within
both private enterprise and shared/collocation facilities.
The historical data generation growth rate exceeds the capacity growth rate of information and
communications technology hardware. In addition, with many governments having “digital agendas” to
provide both citizens and businesses with ever-faster broadband access, the very increase in network
speed and capacity will, by itself, generate ever more usage (Jevons Paradox). Data generation and
the consequential increase in data processing and storage are directly linked to increasing power
consumption.
With this background, data centre growth, and power consumption in particular, is an inevitable
consequence; this growth will demand increasing power consumption despite the most stringent
energy efficiency strategies. This makes the need for key performance indicators (KPIs) that cover
the effective use of resources (including but not limited to energy and water) and the reduction of CO
emissions essential.
Within the ISO/IEC 30134 series, the term “resource usage effectiveness” is more generally used for
KPIs in preference to “resource usage efficiency”, which is restricted to situations where the input and
output parameters used to define the KPI have the same units.
Water usage effectiveness (WUE) is intended to support data centre practitioners in obtaining an in
depth understanding of the performance of the data centre’s cooling installation in comparison with
similar systems, thereby creating a tool for improvning the sustainability of the data centre. The
impact of operational water usage is emerging as being extremely important in the design, location and
operation of current and future data centres.
In order to determine the overall resource efficiency of a data centre, a holistic suite of metrics
is required. This document is one of a series of International Standards for such KPIs and has been
produced in accordance with ISO/IEC 30134-1, which defines common requirements for a holistic suite
of KPIs for data centre resource efficiency. This document does not specify limits or targets for the KPI
and does not describe or imply, unless specifically stated, any form of aggregation of this KPI into a
combination with other KPIs for data centre resource efficiency. This document presents specific rules
on WUE’s use, along with its theoretical and mathematical development. This document concludes with
several examples of site concepts that could employ the WUE metric.
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© ISO/IEC 2022 – All rights reserved

INTERNATIONAL STANDARD ISO/IEC 30134-9:2022(E)
Information technology — Data centres key performance
indicators —
Part 9:
Water usage effectiveness (WUE)
1 Scope
This document specifies water usage effectiveness (WUE) as a key performance indicator (KPI) for
quantifying the water consumption of a data centre during the use phase of the data centre life cycle.
WUE is a simple method for reporting the water intensity of the data centre operating. By reporting
water consumption, it is possible to present the data centre's resource effectiveness.
This document:
a) defines the WUE of a data centre;
b) introduces WUE measurement categories;
c) describes the relationship of this KPI to a data centre’s infrastructure, information technology
equipment and information technology operations;
d) defines the measurement, the calculation and the reporting of the parameter; and
e) provides information on the correct interpretation of the WUE.
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 r
...