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Renewable Energy Installations - Photovoltaic and Battery Systems

T HR SS 80006 ST

Standard

Version 1.0

Issue date: 09 April 2019

© State of NSW through Transport for NSW 2019

T HR SS 80006 ST Renewable Energy Installations - Photovoltaic and Battery Systems

Version 1.0 Issue date: 09 April 2019

Important message This document is one of a set of standards developed solely and specifically for use on

Transport Assets (as defined in the Asset Standards Authority Charter). It is not suitable for any

other purpose.

The copyright and any other intellectual property in this document will at all times remain the

property of the State of New South Wales (Transport for NSW).

You must not use or adapt this document or rely upon it in any way unless you are providing

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This document may contain third party material. The inclusion of third party material is for

illustrative purposes only and does not represent an endorsement by NSW Government of any

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If you use this document or rely upon it without authorisation under these terms, the State of

New South Wales (including Transport for NSW) and its personnel does not accept any liability

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This document may not be current and is uncontrolled when printed or downloaded. Standards

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For queries regarding this document, please email the ASA at [email protected] or visit www.transport.nsw.gov.au © State of NSW through Transport for NSW 2019



Standard governance

Owner: Lead Stations and Buildings Engineer and Lead Electrical Engineer, Asset Standards Authority

Authoriser: Chief Engineer, Asset Standards Authority

Approver: Executive Director, Asset Standards Authority on behalf of the ASA Configuration Control Board

Document history

Version Summary of changes

1.0 First issue

© State of NSW through Transport for NSW 2019 of 41



Preface

The Asset Standards Authority (ASA) is a key strategic branch of Transport for NSW (TfNSW).

As the network design and standards authority for NSW Transport Assets, as specified in the

ASA Charter, the ASA identifies, selects, develops, publishes, maintains and controls a suite of

requirements documents on behalf of TfNSW, the asset owner.

The ASA deploys TfNSW requirements for asset and safety assurance by creating and

managing TfNSW's governance models, documents and processes. To achieve this, the ASA

focuses on four primary tasks:

• publishing and managing TfNSW's process and requirements documents including TfNSW

plans, standards, manuals and guides

• deploying TfNSW's Authorised Engineering Organisation (AEO) framework

• continuously improving TfNSW’s Asset Management Framework

• collaborating with the Transport cluster and industry through open engagement

The AEO framework authorises engineering organisations to supply and provide asset related

products and services to TfNSW. It works to assure the safety, quality and fitness for purpose of

those products and services over the asset's whole-of-life. AEOs are expected to demonstrate

how they have applied the requirements of ASA documents, including TfNSW plans, standards

and guides, when delivering assets and related services for TfNSW.

Compliance with ASA requirements by itself is not sufficient to ensure satisfactory outcomes for

NSW Transport Assets. The ASA expects that professional judgement be used by competent

personnel when using ASA requirements to produce those outcomes.

About this document

This standard sets the minimum requirements for photovoltaic installations, and provides

guidelines on how to achieve them.

This standard contains technical and operational requirements, and was developed by the ASA

in consultation with other TfNSW divisions and agencies.

This is a first issue.




Table of contents 1. Introduction .............................................................................................................................................. 7

2. Purpose .................................................................................................................................................... 7 2.1. Scope ..................................................................................................................................................... 7 2.2. Application ............................................................................................................................................. 7

3. Reference documents ............................................................................................................................. 7

4. Terms and definitions ........................................................................................................................... 10

5. Rail environment.................................................................................................................................... 11 5.1. Safety and risk ..................................................................................................................................... 11 5.2. Electrical capacity augmentation for train stations .............................................................................. 12 5.3. Normal and alternative power source for train stations ....................................................................... 12

6. PVS design ............................................................................................................................................. 12 6.1. Design references ................................................................................................................................ 12 6.2. Feasibility study ................................................................................................................................... 14 6.3. Selection basis ..................................................................................................................................... 14 6.4. Energy efficiency of electrical installation ............................................................................................ 16 6.5. PVS integration with electrical installation ........................................................................................... 16 6.6. PVS connected to the RailCorp electrical network .............................................................................. 19 6.7. PVS connected to an LDNSP network ................................................................................................ 23 6.8. Location of PVS components .............................................................................................................. 24 6.9. PV panel orientation ............................................................................................................................ 24 6.10. PV panel tilt ...................................................................................................................................... 25 6.11. PV panel mounting .......................................................................................................................... 25 6.12. PV panel cleanliness ....................................................................................................................... 26 6.13. PV panel shading ............................................................................................................................. 26 6.14. Earthing, bonding and lightning protection ...................................................................................... 26 6.15. Battery storage ................................................................................................................................ 26 6.16. Emergency procedures .................................................................................................................... 29 6.17. Environmental conditions ................................................................................................................. 29 6.18. Heritage ........................................................................................................................................... 29 6.19. Evaluation methodology .................................................................................................................. 30 6.20. Further design stages ...................................................................................................................... 31 6.21. Alteration to approved design .......................................................................................................... 31 6.22. Critical review process ..................................................................................................................... 32

7. PVS equipment ...................................................................................................................................... 32 7.1. PV panels............................................................................................................................................. 33 7.2. Panel mounting system ....................................................................................................................... 33 7.3. Inverters ............................................................................................................................................... 33 7.4. Batteries ............................................................................................................................................... 35 7.5. PVS management ................................................................................................................................ 36 7.6. Wiring and protection ........................................................................................................................... 37 © State of NSW through Transport for NSW 2019 of 41



7.7. Labelling............................................................................................................................................... 37 7.8. Documentation ..................................................................................................................................... 37

8. Installation, testing and commissioning ............................................................................................. 38 8.1. Performance monitoring ...................................................................................................................... 38 8.2. Periodic maintenance .......................................................................................................................... 38 8.3. Decommissioning and disposal ........................................................................................................... 39

9. Assurance .............................................................................................................................................. 39

Appendix A Feasibility study and evaluation methodology guide for PVS installations ................ 40




1. Introduction Transport for NSW (TfNSW) aims at continual improvement in transport operation, achieving

better economic value and reducing adverse environmental effects.

The application of renewable energy sources should be complemented by usage of

energy-efficient equipment managed by intelligent control systems. Renewable energy sources

should not be used to compensate for energy wasted by inefficient equipment.

This standard includes photovoltaic systems (PVSs) using photovoltaic (PV) panels, with or

without battery storage.

2. Purpose This standard sets requirements for incorporating solar energy generation in TfNSW

installations in a consistent and efficient manner.

2.1. Scope Whilst there are two types of solar technology, PV and thermal, this standard sets requirements

for the design, construction, safe use and efficient operation of grid connected PVS with or

without battery storage.

Stand-alone (not connected to grid) photovoltaic systems as well as solar power generation

using thermal cells are not covered in this standard.

2.2. Application This standard applies to all stages of a PVS life cycle including planning, design, construction,

operation, maintenance and decommissioning. This standard applies to all new installations

including upgrades and additions or changes to existing installations.

While the document covers railway installations including stations, offices, car parks and other

rail facilities such as stabling yards, the guiding principles and requirements described in this

standard can be applied for other transport modes.

3. Reference documents The following documents are cited in the text. For dated references, only the cited edition

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

International standards

IEC 61215-1 Ed.1.0 (all parts) Terrestrial photovoltaic (PV) modules - Design qualification and

type approval




IEC 61730-1 Ed. 2.0 Photovoltaic (PV) module safety qualification - Part 1: Requirements for

construction

IEC 62109-1 Ed. 1.0 Safety of power converters for use in photovoltaic power systems - Part 1:

General requirements

IEC 62109-2 Ed. 1.0 Safety of power converters for use in photovoltaic power systems - Part 2:

Particular requirements for inverters

Australian standards

AS 2676.1-1992 Guide to the installation, maintenance, testing and replacement of secondary

batteries in buildings - Part 1: Vented cells.

AS 2676.2-1992 Guide to the installation, maintenance, testing and replacement of secondary

batteries in buildings - Part 2: Sealed cells

AS 3011.1 Electrical Installations - Secondary batteries installed in buildings – Part 1: Vented

cells

AS 3011.2 Electrical Installations - Secondary batteries installed in buildings - Part 2: Sealed

cells

AS 4086.1 Secondary batteries for use with stand-alone power systems - Part 1: General

requirements

AS 4086.2 Secondary batteries for use with stand-alone power systems - Part 2: Installation

and maintenance.

AS 60529 Degrees of protection provided by enclosures (IP Code)

AS IEC 62619:2017 Secondary cells and batteries containing alkaline or other non-acid

electrolytes - Safety requirements for secondary lithium cells and batteries, for use in industrial

applications

AS/NZS 1170.1 Structural design actions - Part 1: Permanent, imposed and other actions

AS/NZS 1170.2 Structural design actions - Part 2: Wind actions

AS/NZS 1768 Lightning protection

AS/NZS 3000 Electrical installations (known as the Australian/New Zealand Wiring Rules)

AS/NZS 3008.1.1 Electrical installations - Selection of cables – Part 1.1: Cables for alternating

voltages up to and including 0.6/1 kV - Typical Australian installation conditions

AS/NZS 3017 Electrical installations - Verification guidelines

AS/NZS 4509.1:2009 R2017 Stand-alone power systems - Part 1: Safety and installation

AS/NZS 4509.2:2010 R2017 Stand-alone power systems - Part 2: System design




AS/NZS 4777.1:2016 Grid connection of energy systems via inverters - Part 1: Installation

requirements

AS/NZS 4777.2 Grid connection of energy systems via inverters - Part 2: Inverter requirements

AS/NZS 5033:2014 Installation and safety requirements for photovoltaic (PV) arrays

AS/NZS 61000 Electromagnetic compatibility (EMC) (series)

Transport for NSW standards

EP 03 00 00 01 TI Rectifier Transformer & Rectifier Characteristics

EP 12 10 00 20 SP Low Voltage Distribution Earthing

EP 12 10 00 21 SP Low Voltage Installations Earthing

EP 90 10 00 02 SP Standard Voltage Tolerances

T HR EL 17001 ST Electrical Distribution System Installation Connection and Inspection

T HR SS 80002 ST Low Voltage Electrical Installations

T MU AM 01001 ST Life Cycle Costing

T MU AM 01008 ST Technical Maintenance Plans and Coding System

Legislation

NSW Heritage Act 1977

Rail Safety National Law (NSW) 2012

Other reference documents

Clean Energy Council 2017, Battery Install Guidelines for Accredited Installers

Clean Energy Council 2017, Clean Energy Council Install and Supervise Guidelines for

Accredited Installers

Department of Planning & Environment, Division of Energy, Water and Portfolio Strategy, July

2018, Service and Installation Rules of New South Wales

Energy Networks Australia, ENA Doc 035 - 2014 Power Quality Guideline for Inverter Energy

Systems for Connection to Low Voltage Distribution Networks

Office of Environment and Heritage 2014, NSW Government Resource Efficiency Policy

Office of Environment and Heritage 2016, NSW Climate Change Policy Framework

PR D 78000 Electrical Network Safety Rules

RailCorp Section 170 Heritage and Conservation Register




SA/SNZS TR IEC 61000.3.14:2013 Electromagnetic compatibility (EMC) – Part 3.14: Limits –

Assessment of emission limits of harmonics, interharmonics, voltage fluctuations and unbalance

for the connection of disturbing installations to LV power systems.

The Australian Building Codes Board, National Construction Code, volume one

Transport for NSW 2017, Sustainable Design Guidelines

4. Terms and definitions The following terms and definitions apply in this document:

ac alternating current

alternative power supply an independent supply to an installation connected using a change-

over arrangement. This does not include a UPS or battery backup

ASA Asset Standards Authority

AEO Authorised Engineering Organisation

BIPV building integrated photovoltaic

CEC Clean Energy Council

containment cable tray, cable ladder, wire basket, pipe, tube, duct, conduit or cable trunking for

the housing or protection of cables

dc direct current

DSMSB distribution supply main switchboard; the first LV switchboard between the transformer

terminals and the LV installation. The DSMSB is the location to establish the one and only

connection between earth and neutral.

EDU electrical distribution unit; the name of the business unit accountable for the rail transport

distribution network supply provider responsibilities. The EDU currently resides in Sydney

Trains.

installation means electrical installation unless otherwise required by the context

IP ingress protection

IMSB installation main switchboard; the low voltage switchboard from which the supply to the

whole installation can be controlled. The installation prefix is used in this standard to distinguish

the IMSB from the DSMSB

kWh kilowatt hour

LDNSP local distribution network supply provider

LV low voltage; voltage exceeding 50 V ac or 120 V ripple-free dc but not exceeding 1000 V ac

or 1500 V dc




PCC point of common coupling

PV photovoltaic

PV panel solar photovoltaic panel

PVS photovoltaic system with or without battery storage

switchboard an assembly of circuit protective devices, with or without switchgear, instruments

or connecting devices, suitably arranged and mounted for distribution to, and protection of, one

or more submains or final subcircuits or a combination of both (AS/NZS 3000)

TfNSW Transport for NSW

5. Rail environment The rail environment is a high risk environment with technical and legal constraints that may not

be present in other areas where renewable energy is generated and used.

5.1. Safety and risk The PVS shall not impose a safety hazard to customers and members of the public and

personnel working on the network.

The Rail Safety National Law (NSW) 2012 requires that potential hazards be eliminated, or if

not possible, controlled so far as is reasonably practicable (SFAIRP), to ensure the safety of the

public and staff. Any risks associated with PVSs need to be assessed and addressed. The

requirements of the Rail Safety National Law (NSW) 2012 take precedence over legislated

requirements for non-rail applications.

Specific safety considerations for any transport application shall be, but not limited to, the

following:

• space, location and accommodation of all elements of a PVS

• fire hazards related any aspect of PVS operation

• hazards related to electrical energy and electrical safety

• earthing, bonding and lightning protection

• equipment-specific chemical and explosion hazards

• consequential hazards

• requirements related to people safety considering dynamic nature of passenger crowding

in transport facilities

• requirements related to ongoing operational continuity of public transport




Additional requirements may need to be satisfied in addition to those specified in this standard.

Such requirements shall be identified and addressed as part of the project process.

5.2. Electrical capacity augmentation for train stations PVS with or without battery storage shall not be used for electrical capacity upgrades for

existing installations due to the requirement for a reliable power supply.

5.3. Normal and alternative power source for train stations PVSs, with or without battery storage, are not considered suitable as an alternative power

supply as defined in T HR SS 80002 ST Low Voltage Electrical Installations. This is because for

a PVS to be viable, the majority of energy needs to be consumed as it is produced.

6. PVS design Many factors contribute to choosing an appropriate renewable energy solution. Where used, a

PVS shall be developed as part of a holistic design solution for a particular facility and not

replace or preclude the requirements for energy-efficiency for any TfNSW facility or its part.

PVS installations can be integrated with buildings and other infrastructure. The appropriateness

and technical suitability of a PVS installation should be assessed based on the guidance in this

standard.

The design work shall be carried out by a suitably qualified professional accredited by the Clean

Energy Council (CEC) for the design of grid-connected photovoltaic power systems. Where the

system is connected to a storage battery then the designer shall also have CEC endorsement

for battery storage (for grid-connected systems).

PVS design and installation shall be assured by an AEO. If a PVS is procured as a stand-alone

contract to either TfNSW or Sydney Trains, Sydney Trains can assume the role of an AEO for

assurance purposes.

PVS design and connection to the network shall be reviewed and approved by the Electrical

Distribution Unit (EDU) prior to purchasing any PVS equipment and commencement of any work

on site.

6.1. Design references To ensure that potential effects of connecting a PVS to the low voltage (LV) network can be

assessed in a standardised way it is necessary to establish reference points at which such

change can be measured and compared.




6.1.1. Point of common coupling

The point of common coupling (PCC) is defined as follows:

• for LDNSP networks, the PCC is defined in the NSW Department of Planning &

Environment, Division of Energy, Water and Portfolio Strategy Service and Installation

Rules of New South Wales

• for the RailCorp electrical network, the PCC is defined as the point at the distribution

supply main switchboard (DSMSB) to which the installation main switchboard (IMSB)

supply cable is connected

The electrical assets on the installation side of the PCC are dedicated for the use of that

electrical installation.

6.1.2. Point of supply The point of supply is defined as follows:

• for LDNSP networks, the point of supply is defined in AS/NZS 3000 Electrical installations

(known as the Australian/New Zealand Wiring Rules)

• for the RailCorp electrical network, the point of supply is the same as the PCC

6.1.3. Point of PVS connection to an electrical installation The following describes appropriate PVS to an electrical installation connection topology:

• for PVSs connected to an LDNSP network, the PVS connection point location shall be as

allowed by the Service and Installation Rules of New South Wales

• for PVSs connected to the RailCorp electrical network, but are prohibited to export energy

into the RailCorp electrical network, the PVS connection at the installation supply main

switchboard IMSB is preferable but other locations can be used where justified and

approved

• for PVSs that are connected to the RailCorp electrical network, and are allowed to export

energy into the RailCorp electrical network, the PVS connection point should be at the

switchboard with closest proximity to the PCC, which is the installation supply main

switchboard IMSB

6.1.4. Point of PVS connection to RailCorp LV distribution network The point of PVS connection shall be agreed with the EDU prior to commencement of the

project. Additional requirements may apply.




6.1.5. Compliance prerequisites PVS installations described in this document shall comply with the following:

• relevant legislation, regulations and local authority requirements as applicable

• Service and Installation Rules of New South Wales

• Australian standards, including AS/NZS 5033:2014 Installation and safety requirements for

photovoltaic (PV) arrays and normative documents listed therein

• CEC, Clean Energy Council Install and Supervise Guidelines for Accredited Installers and

CEC, Battery Install Guidelines for Accredited Installers

• requirements of PR D 78000 Electrical Network Safety Rules (ENSR) and consideration of

the maintenance activities in accordance with ENSR

• requirements in this document

The EDU shall be consulted for each PVS project to obtain approval for the installation

methodology, connection to and the use of a particular switchboard.

6.2. Feasibility study Prior to commencing any PVS project, a feasibility study shall be carried out to assess the

technical, financial and environmental viability of installing and operating a PVS at a particular

site and to select the most optimal solution.

A feasibility study can be carried out by competent, suitably qualified internal staff or similarly

qualified external consultants. The feasibility study shall form the basis of any further work.

The feasibility study shall also investigate how the proposed PVS affects the existing

installation, including consideration of the installation power factor. The PVS shall not degrade

the installations power factor below a level of 0.90.

6.3. Selection basis PVS selection shall be guided by the NSW Government Resource Efficiency Policy that aims to

reduce operating costs and lead by example in increasing the efficiency of the resources it

uses.

While the capital cost of a PV panels and inverters has reduced, the cost of battery storage is

relatively high. The location and orientation of system elements can significantly affect the

efficiency and life cycle cost of a PVS. Rooftop-mounted systems are the most common.

Building-integrated or free-standing systems may be considered where feasible and supported

by a business case and approved by the operator and maintainer.




Life cycle costing shall be used for evaluation of different PVS alternatives and available

options. The life cycle costing of various PVS choices shall use a time-base that is common to

all systems being compared. Unless, based on an appropriate justification, other length of time

is selected by project stakeholders, PVS system life of 25 years shall be used as a common

time-base for comparison of the life cycle costing calculations.

All assumptions and parameters used in the life cycle costing calculations shall be documented

as part of the assurance process.

A large number of transport facilities at various locations could be considered for PVS

installations. While priority should be given to installations providing the best economic benefit

and shortest payback periods, the cost should not be used as the only deciding factor in

selecting a system. Other factors include the following:

• Analysing costs and benefits not only in commercial but also in environmental and social

terms for each proposed system choice. Such considerations should include all relevant

factors from the time of the system purchase to the time of system disposal at the end of its

life –whole-of- life should be considered.

• Including embodied energy of materials and system parts (being the energy that was used

in the work of making a product and transport up to the point in time when the product was

acquired for a TfNSW project) in the considerations.

• Adopting cost effective products and services in accordance with the objectives of NSW

Government Resource Efficiency Policy.

• Innovation that supports TfNSW objectives.

6.3.1. Building integrated photovoltaics PVSs can be amalgamated into building structures by replacing traditional building materials or

elements such as windows, facades, louvres, roofing and so on with building integrated

photovoltaic (BIPV) components that retain or mimic the original material functionality whilst

producing electrical energy.




These bespoke systems are more complex and can be relatively costly, but can provide

environmental and aesthetic benefits while reducing operational energy cost. The BIPV

electrical performance is often poorer compared to similar size traditional PVSs owing to the

following:

• non-optimal orientation and tilt due to design constraints, for example a south facing curtain

wall

• increased likelihood of partial shading for example, protruding objects and neighbouring

structures

• higher operating temperatures for example, solar tiles installed flush on a surface will have

minimal airflow, which may also increase module electrical degradation

BIPV design shall consider all aspects of the traditional building elements that are being

replaced by BIPV to account for different functionality, aesthetics, natural lighting, weather

protection, durability and so on. These considerations include the design life of BIPV and

determination of what degradation in a single function is acceptable before the building end of

life. As an example, a solar roof tile may be able to continue to function as a roof tile beyond 25

years but the electrical production will be severely degraded.

As BIPV systems combine builder and electrical works BIPV systems shall meet the

requirements of the relevant building codes and electrical standards.

An holistic approach to maximise the benefits while limiting the disadvantages is encouraged.

6.4. Energy efficiency of electrical installation Before a PVS is considered for a particular facility, existing electrical and other building services

installations shall be examined to identify any operational measures or retrofit solutions that

could improve the overall energy efficiency. Appropriate site-specific energy efficiency

measures shall be implemented before the addition of any renewable energy sources are

considered.

Possible measures include replacing inefficient equipment with energy efficient equipment,

introducing automated controls and better operational procedures. This process is also

applicable for new projects. As a minimum, the provisions of TfNSW Sustainable Design

Guidelines should be followed.

6.5. PVS integration with electrical installation All PVSs shall be grid connected systems. Requirements of Section 8 of Service and Installation

Rules of New South Wales apply.

Prior to PVS design, the electrical loads shall be analysed to estimate half-hourly power

demand profile in typical twenty-four-hour periods, separately for weekdays and weekends. This




analysis will allow for the calculation of average, minimum and maximum electrical demand

during different months of a year (especially during winter and summer months). This will

facilitate understanding of when the renewable energy generation would be most needed and

best utilised.

The installation power demand can be quantified based on existing energy consumption data,

site measurements, or an informed estimate. The outcome shall be properly documented and

used as part of the basis for sizing the renewable energy installation.

6.5.1. PVS sizing PVSs may export energy to RailCorp or LDNSP networks as described in Section 6.6.2 and

Section 6.7.

Where no export is considered, the PVS shall be configured to comply with Section 6.6.1.

Where feasible and supported by a business case battery storage can be considered.

The size of the proposed PVS should be informed by the following:

• size and power demand profile of the existing (or proposed in case of a new) electrical

installation

• satisfactory operation, so that frequent shutdown and start-up of the inverter is prevented

• asserted goals (in terms of the renewable energy compared to total energy requirements)

• special circumstances, for example, where a battery storage option is considered

This will help to determine preliminary system size, configuration and design including the

number and dimensions of PV panels required. The sizing process shall include optimal PV

panels positioning and preliminary equipment selection.

The use of specialised software is recommended to aid sizing calculations.

6.5.2. Energy metering Energy generation data is reported by inverter control system for PVSs that are prohibited from

exporting energy into the RailCorp electrical network. No additional metering is required.

To measure and report the energy used by the installation for PVSs that are allowed to export

energy into RailCorp electrical network, the energy exported to the network plus the sum thereof

(equal to the total PVS generated energy) would be desirable.




The following arrangements can be used, with the operator and maintainer making the

determination:

• Where net accounting for the energy usage from the RailCorp electrical network is not

required, the existing energy metering arrangement can be retained. Accounting for PVS

generated energy components (that is, usage and export) would be expected by accessing

PVS data with a detailed proposal being developed and approved before PVS design is

finalised.

• Where net accounting for the energy usage from the RailCorp electrical network is

required, the existing energy metering needs to be replaced with net metering.

For PVSs that are allowed to export energy into to an LDNSP network, net metering

arrangements are necessary. Detailed metering requirements are contained within the Service

and Installation Rules of New South Wales and the relevant LDNSP's documents.

Further information regarding metering arrangements can be obtained from the operator and

maintainer.

6.5.3. PVS connection to an existing or new electrical installation

Connection of a PVS to an existing or new electrical installation shall not create a situation

where the reliability of the supply network is degraded. Operation of the PVS shall not cause

undue interference with the supply to other parts of the installation or the supply network.

The PVS integration with the existing or new electrical installation shall comply with

AS/NZS 4777.1:2016 Grid connection of energy systems via inverters - Part 1: Installation

requirements and AS/NZS 4777.2 Grid connection of energy systems via inverters - Part 2:

Inverter requirements.

There may be additional requirements for installations in unique situations. These requirements

should be identified by the designer and operator and maintainer at the initial planning stage.

The operator and maintainer is an inspecting authority and no PVS installation can be

connected to either the RailCorp electrical network or an LDNSP network until that work has

been inspected and approved for connection by the EDU or other relevant inspecting authorities

as part of the mandatory inspection.

Application for connection in accordance with T HR EL 17001 ST Electrical Distribution System

Installation Connection and Inspection shall be submitted by the PVS designer as early as

practicable in the design phase.




6.6. PVS connected to the RailCorp electrical network The requirements detailed in Section 6.6.1 to Section 6.6.2 shall apply to all PVS installations

connected to the RailCorp LV installation or distribution network. These requirements shall be

read in conjunction with the Service and Installation Rules of New South Wales.

6.6.1. Requirements for PVSs when export to the RailCorp electrical network is not permitted To prevent adverse impacts on safe and reliable operation of the network, unless explicit

approval is granted, the PVS shall not export power into the RailCorp LV distribution system.

That means the power generated by the PVS operating in parallel with RailCorp’s network may

only be consumed by the installation to which it is connected.

The nominated control logic and current thresholds are designed to concurrently achieve 'no

export'. The PVS shall be equipped with an anti-export controls which connect and disconnect

the inverter from the installation, via a contactor, as follows:

• in normal operation the IMSB incoming supply from the RailCorp LV distribution network

cable load is above 5 A per phase and the contactor is closed

• if the IMSB incoming supply cable load falls below 5 A on any phase the PVS inverters will

disconnect immediately, that is, the contactor is open

• if the IMSB incoming supply cable load has risen above 5 A but for less than 60 sec, the

contactor remains open

• if the IMSB incoming supply cable load remains greater than or equal to 5A for 60 seconds

the PVS inverters will be reconnected, that is, the contactor will close

Alternative means

The following alternative means of export prevention may be employed subject to written

approval from the EDU:

• the use of inverters equipped with suitable ramp rate management to ensure zero export

can be considered to prevent anti-export operation, however a PVS should be sized to

avoid frequent intervention of the inverter controls

• omission of anti-export controls can be considered if it can be demonstrated that a PVS will

never be able to export beyond the installation due to relatively small PVS when compared

with the total installation load




6.6.2. Requirements for PVSs when export to the RailCorp electrical

network may be permitted Where there is ability to feed the excess energy back to the grid and there is a business case to

justify this approach, export to the RailCorp electrical network may be permitted.

Operation of the RailCorp LV network and feasibility of exporting PVS generated energy to the

network is limited by the network topology at the PVS point of connection, therefore the extent

of the permitted export needs be accurately determined, its size limited to a defined amount and

strictly controlled.

This is largely driven by the thermal capacity of the distributor feeders, the impedance of the

feeder (causing voltage rise), the distribution transformer rating and the combined effect of the

connected generation plant on RailCorp electrical network performance, operation and safety.

Permitted PVS capacity and export assessment criteria

The designer shall assess the feasibility of PVS connection at a particular point within the

network and select the optimal size of a PVS based on a number of criteria. These include, but

are not limited to, the following:

• the level of other generation already connected

• the proposed size of the PVS against the size of the transformer to which the installation is

connected

• the proposed export, which is the surplus of PVS generated energy at a given moment in

time over the energy consumed by the installation to which the PVS is connected

• the electrical strength, voltage and protection requirements of the RailCorp electrical

network at the PVS point of connection

• the requirements of T HR EL 17001 ST related to connection and inspection of electrical

installations

The PVS design shall demonstrate compliance with power quality requirements in accordance

with AS/NZS 4777 and comply with Energy Networks Australia ENA Doc 035 - 2014 Power

Quality Guideline for Inverter Energy Systems for Connection to Low Voltage Distribution

Networks and SA/SNZS TR IEC 61000.3.14:2013 Electromagnetic compatibility (EMC) – Part

3.14: Limits – Assessment of emission limits of harmonics, interharmonics, voltage fluctuations

and unbalance for the connection of disturbing installations to LV power systems.




Installation that integrates a PVS intended to export energy into RailCorp LV network shall be

designed so that the following conditions are met:

• the voltage limits at the LV terminals of a RailCorp distribution transformer will not exceed +

5% - 8% for steady state and + 8% - 10% for transients (EP 90 10 00 02 SP Standard

Voltage Tolerances)

• maximum voltage rise between the IMSB and the PCC, that is the DSMSB, that is

measured on the cables linking DSMSB and the IMSB shall not exceed 1% of the nominal

PCC voltage

• maximum voltage rise between the PVS point of connection and the installation main

switchboard IMSB shall not exceed 1% of the nominal PCC voltage

• disconnection or failure of the PVS shall not cause the corresponding DSMSB voltage sag

to adversely affect the operation of the rail signalling system

The combined impedance of the cables between the point of the PVS connection to the

installation and the PCC (that is DSMSB) shall be low enough to ensure that the voltage rise

calculated between these two points shall not exceed values shown in diagram 1 and 2 below.

The voltage rise shall be calculated using full rated current of the PVS. The calculation can

substitute the full rated current of the PVS by an agreed export limit where curtailing of the PVS

output when the net export power exceeds the threshold of the agreed export limit is ensured.

Figure 1 and Figure 2 show typical PVS connection methods to the RailCorp electrical network.

DSMSB IMSB

Distribution board

Distribution board

RailCorp distribution

network

RailCorp distribution

networkLV installationLV installation

PCC and point of supplyPCC and point of supply Point of PVS connectionPoint of PVS connection

1% maximumvoltage rise





Figure 1 - PVS connected downstream of IMSB



RailCorp

distributionRailCorp

distribution LV installationLV installation

DSMSB IMSB

Distribution board

Distribution board

PCC and point of supplyPCC and point of supply Point of PVS connectionPoint of PVS connection



Figure 2 - PVS connected at IMSB

In some instances, network augmentation or additional protection and control functions (for

either or both RailCorp electrical network and the PVS) may be required to ensure network

safety and performance standards are not compromised.

The EDU shall review the network study and advise the designer if additional work is required.

Network study

The technical considerations and resulting assurance that the PVS size and connection

topology shall not unduly degrade relevant electrical parameters at either the DSMSB or IMSB

shall be based on a network study.

The main purpose of the network study is to assess the extent of the proposed export in context

of the size and characteristics of relevant network elements to establish safe export limits. The

network study shall determine the maximum PVS capacity that can be connected to a particular

point at the RailCorp electrical network and the maximum export allowed. There may be cases

where the proposed system may be required to connect at a reduced capacity or where no

connection is allowed.

The network study shall determine the aggregate effect of the PVS and other embedded

generation during various load conditions on the LV network and the 11 kV network, and include

but not limited to the following considerations:

• network disturbances (for example, voltage and current harmonics and fluctuations)

• steady state voltage rise (on LV network, high voltage (HV) network or both)

• protection for anti-islanding

• current carrying capacity of the LV network




The scope of the network study is shown in Table 1. To ensure that all relevant aspects are

adequately covered, the study scope shall be extended as deemed necessary by the designer.

Table 1

Task Description Procedure

1 Review enquiry form

• are location, capacity, voltage, connection and timing details provided?

2 Check inverter compliance to AS 4777

• CEC compliance • manufacturer's certificate available • AS 4777.2 compliance • witness testing if required

3 Model LV network • obtain data on connected load - minimum, maximum estimates, or confirm network data - feeder and service type, length, substation details

• model LV network downstream of distribution transformer including the PVS connection point and the PCC

4 Network studies • check 11 kV feeder loading level (% thermal rating) under minimum local load demand conditions

• check LV distributor loading level (% thermal rating) under minimum local load demand conditions

• check distribution transformer loading level (% thermal rating) under minimum and maximum local load demand conditions

• check voltage (% Vn) under minimum load at PCC • check voltage (% Vn) under maximum load at PCC • check fault level, that is, kA at IMSB and DSMSB • check voltage and current disturbance and harmonics against

limits for compliance • check power factor under all operating conditions • check protection methodology and satisfactory operation for

all types of network faults

5 Assess risk level of islanded operation. Increased risk if at least one of check 1 to check 4 is not met.

• check load generation match (Sinv: Sload <0.7) • check [Pinv]:[Pload] <0.8 or >1.2 • check [Qinv]:[Qload] <0.8 or >1.2 • number of single phase and three phase inverters on LV

feeder

Where the combined capacity of all PVSs connected to the same RailCorp distribution

transformer does not exceed 10% of the capacity of the transformer the network study is not

required.

6.7. PVS connected to an LDNSP network The connection and export of energy to an LDNSP LV network is not prohibited, however, it is

subject to an agreement with the EDU and the relevant LDNSP.




In addition to LDNSP approval, approval shall be obtained from the EDU before a PVS is

permitted to export power into an LDNSP network.

Special care shall be given to installations connected to an LDNSP through an isolation

transformer. Installations supplied from an isolation transformer form part of the RailCorp

electrical network regardless of the LDNSP.

6.8. Location of PVS components The site and structure, or structures, on which PV panels are to be installed shall be selected to

facilitate compliance with the requirements of this standard.

The location and mounting of PV panels shall be chosen to ensure that they are easily

accessible for cleaning and maintenance but secure from vandalism.

PV panels or other parts of a PVS shall be mounted at least 2 m away from the 1500 V direct

current (dc) overhead wiring and its support structures. EP 12 10 00 21 SP Low Voltage

Installations Earthing provides further detailed requirements.

No equipment shall be located in areas where access for any maintenance can only be

achieved by securing a possession that is, taking a rail track or tracks out of use for work to be

able to proceed.

The location of PVS components shall be approved by the operator and maintainer.

Clear labelling shall be provided for emergency services to easily locate the relevant isolating

devices. These devices shall be accessible to emergency services at all times.

6.9. PV panel orientation The energy production of a PV panel is at its maximum when the sun is hitting the panel

perpendicular. That can be controlled by the panel's orientation (north, south, east or west) and

tilt (the angle of the panel from the surface of the earth).

Fixed installations are recommended. Installations that track the sun in real time (active solar

tracking) in order to achieve optimal panel position at different times of day are not

recommended for TfNSW applications as their life cycle cost is likely to exceed the expected

benefits.

To maximise year round energy production PV panels should be facing as close to true north as

possible. With north being 0 degrees or 360 degrees, any north-facing orientation between 60

degrees and 300 degrees is permitted. North-facing panel orientation between 90 degrees and

270 degrees may be acceptable where justified by relevant site factors. Installations where

panels are oriented outside these parameters are prohibited unless it can be shown that there is

a strong financial case for doing so.




For example, if an installation's dominant loads (power demand) occur during mornings, PV

panel orientation towards the east (utilising the best of morning sun) would be more acceptable

than the PV panel orientation towards the west.

6.10. PV panel tilt To maximise year round energy production, PV panel tilt should be equal to the latitude angle of

the location of the panels (for example, 34 degrees in Sydney).

Panels located on roofs that are flat (that is, less than 34 degrees in Sydney) will yield more

energy in summer. These would be well suited where an installation's dominant loads occur

during summer.

Panels located on roofs that are steep (that is, more than 34 degrees in Sydney) will yield more

energy in winter. The steep roof installations would be more suited to contribute to winter loads,

responding to different sunlight incidence angles at that time of the year.

These factors shall be carefully considered against mounting the panels flush with the roof,

which, considering the cost of additional tilt frames, usually provide a better overall financial

outcome. Panels following the roofline would also be more acceptable for aesthetic reasons.

For example, for facilities with large air-conditioning loads (that predominantly occur on summer

afternoons), the PV panel orientation towards the north or north-west, on a flat roof, would result

in maximum electricity generation during these times.

6.11. PV panel mounting Panel mounting options considerations include the type, height and accessibility of roof or an

alternative mounting location, and whether tilt frames are required. The easiest mounting option

is where PV panel installation follows the angle of the roof.

An increase in panel temperature will considerably reduce a PV panel power output (typically by

15%-25% for panels mounted directly onto the roof). Consequently, a key consideration for

panel mounting is ability to reduce the panel temperature by convective cooling. This can

usually be achieved by providing a gap greater than 150 mm between the panels and the roof.

Other considerations for PV panel mounting include the following:

• site preparation needs, for example improving the condition of roofs, removal of trees or

other shading

• structural integrity as the building structure shall be capable of supporting the weight of PV

panels plus the weight of maintenance personnel at any one point of attachment




6.12. PV panel cleanliness PV panel surfaces shall be periodically cleaned to maintain expected level of performance over

the life of the panel.

A larger tilt will contribute to self-cleaning, however self-cleaning is largely dependent on rainfall

and may be inadequate for soiling problems such as bird droppings, which can potentially lead

to other issues such as thermal hotspots and damage.

6.13. PV panel shading PV panel electrical output is extremely sensitive to shading. The panel location shall be chosen

to ensure that shading from local topography and features such as nearby structures or trees

(and their growth over time) is completely eliminated, as even partial shading has major adverse

effect on energy production.

Neighbouring topography shall be included in overall considerations to account for any other

factors that may affect energy production.

6.14. Earthing, bonding and lightning protection PVS earthing and bonding shall be designed and installed in conformance with AS/NZS 5033,

EP 12 10 00 21 SP and EP 12 10 00 20 SP Low Voltage Distribution Earthing.

A PVS shall be installed in conformance with AS/NZS 1768 Lightning protection. The location

and mounting of PV panels shall not interfere with or affect in any way the operation of a

lightning protection system nor shall lighting protection system interfere with the operation of PV

panels.

In any case, the minimum conductor size shall be 16 mm2 copper.

6.15. Battery storage A battery stores the excess energy produced by an energy generation system for use at times

when the system is not able to generate enough energy to meet the demand.




For grid-connected system, energy stored in batteries can be used for the following:

• Reducing energy demand peaks in installations that are subject to a demand charge, also

known as capacity charge. Demand charge is an element of a commercial tariff where an

additional charge is determined by the installation's maximum half-hourly power reading

(load) during either a month or the 12 months prior to the bill being calculated.

• Reducing the energy costs during peak hours in installations that use peak, shoulder or off-

peak energy tariffs.

• Other forms of tariff optimisation that include charging batteries with cheap energy off-peak

and discharging (using the power) during times when the cost of energy is high.

Enabling the islanding function when utilising battery storage is prohibited.

Whilst many battery storage solutions are technically feasible, the energy tariff applicable to the

RailCorp electrical network does not involve any demand charge, and the difference between

peak and shoulder or off-peak tariff is smaller compared to other Australian commercial tariffs.

This significantly limits the attractiveness and possible monetary benefits of using battery

storage in TfNSW installations. Combined with relatively high initial acquisition cost it may make

battery storage uneconomical at present costs.

Currently there are a number of installations connected to the RailCorp electrical network where

surplus energy generated by a PVS could be stored in batteries for use at different times,

increasing consumption of renewable energy.

Depending on the battery type and chemistry, the losses associated with battery charging and

discharging amount to 10% to 15% of the stored energy. After adding the embodied energy

related to manufacturing and transport of the battery, from the sustainability point of view grid

export would be more efficient compared to using battery storage.

The basis of the battery sizing shall include the following:

• analysis of seasonal PVS energy generation and the installation energy consumption

patterns and differences during summer, winter, and intermediate seasons

• estimation of the amount of PVS generated energy (kWh) in the course of an average year

• estimation of the amount of PVS energy (kWh) that will be used directly (during daytime

hours) in the course of an average year

• comparison with the installation total energy use in the course of an average year

• consideration of various PV panels sizing compared to battery sizing options to best

address the particular project situation and maximise financial advantages of the proposed

solution over the installation life cycle




• consideration of the battery depth of discharge (that varies according to the battery

chemistry) during everyday operation, as it can have a significant impact on the battery life

• the use of specialised design software

Several different types of batteries utilising various older and newer technologies are available

for use in a renewable energy system. The selection of a particular battery type shall be based

on life cycle costs that include not only the battery but also costs associated with the following:

• available location

• size and construction of battery room or enclosure

• environmental conditions that need to be provided for battery to safeguard optimal battery

performance over time

• maintenance costs related to a particular battery type, for example a lithium-ion battery, is

likely to require less maintenance than a lead acid battery

• safety precautions including fire risk and other hazards associated with the battery

chemistry

• ventilation provisions and the like

All batteries shall be accommodated, installed and maintained in compliance with the following,

as relevant:

• section 3 and section 4 of AS 2676.1-1992 Guide to the installation, maintenance, testing

and replacement of secondary batteries in buildings - Part 1: Vented cells

• section 3 and section 4 of AS 2676.2-1992 Guide to the installation, maintenance, testing

and replacement of secondary batteries in buildings - Part 2: Sealed cells

• AS 3011.1 Electrical installations - Secondary batteries installed in buildings – Part 1:

Vented cells

• AS 3011.2 Electrical installations - Secondary batteries installed in buildings - Part 2:

Sealed cells

• section 7 and section 8 of AS/NZS 4509.1:2009 R2017 Stand-alone power systems. Part

1: Safety and installation

• section 4.6 of AS/NZS 4509.2:2010 R2017 Stand-alone power systems. Part 2: System

design

• AS 4086.1 Secondary batteries for use with stand-alone power systems - Part 1: General

requirements




• AS 4086.2 Secondary batteries for use with stand-alone power systems - Part 2:

Installation and maintenance

• AS IEC 62619:2017 Secondary cells and batteries containing alkaline or other non-acid

electrolytes - Safety requirements for secondary lithium cells and batteries, for use in

industrial applications

The design and installation of room ventilation, airconditioning, lighting and power provisions

shall take into account battery chemistry as explosive gasses may be present inside the room.

Batteries shall be separated from the remainder of the building with construction complying with

the National Construction Code, volume one. The fire resistance level (FRL) may have to be

increased if determined by the risk assessment of site-specific safety requirements.

Carbon dioxide or ABC powder type portable fire extinguishers shall be provided next to the

battery room entry door. Additional fire detection and fire protection measures commensurate

with the risks related to specific battery type and size shall be implemented.

6.16. Emergency procedures Safety requirements in AS/NZS 5033 and the CEC Battery Install Guidelines for Accredited

Installers shall be complied with.

System isolating switches shall be easily accessible at all times by the operator and maintainer

staff and emergency services. A copy of the shutdown procedure shall be displayed on the fire

indicator panel and in the fire control room, beside the PVS inverter, at the PVS connection

point to the network and the DSMSB.

6.17. Environmental conditions Environmental conditions in rooms housing inverters or battery storage shall comply with the

equipment manufacturer's recommendations. Emergency escape lighting shall be provided in

inverter rooms, battery storage rooms and in all locations where PVS mandatory on and off

switches are housed.

6.18. Heritage The use of PVSs within heritage precincts is generally discouraged due to the likelihood of

increased technical complexity and increased cost of installing a system, given the need to

consider adverse visual impacts and undesirable impacts to heritage fabric from system

elements.

Where a PVS is proposed within a heritage precinct, it shall be located on structures with no

identified heritage significance. For further information on heritage listed assets, refer to the

RailCorp Section 170 Heritage and Conservation Register.




Heritage impacts of a PVS installation shall be adequately assessed by a competent heritage

professional and an application for works submitted, as required, in accordance with the NSW

Heritage Act 1977.

Where PVSs are required to be located on or adjacent to heritage structures, detailed design of

the proposed installation shall be undertaken by a competent heritage professional who is a

registered architect. The design shall not compromise significant heritage fabric, shall mitigate

any visual impact in consideration of the bulk, scale and reflectivity of the product and fixings,

and shall not conceal or damage heritage fabric or building fabric. Any fixings to heritage fabric

shall be reversible.

6.19. Evaluation methodology Evaluation of project feasibility shall be based on the considerations described in Section 6.2 to

Section 6.18 resulting in project-specific conceptual proposals detailed enough to facilitate life

cycle costing and cost benefit evaluation of various available options. The evaluation results will

inform the decision to proceed or not with the project.

The methodology and key feasibility assessment elements are shown in Appendix A. In

addition, the following shall be included in PVS feasibility evaluation:

• Integration with electrical installation including the need for installation upgrades, for

example, distribution board, meter or cabling. Any other work that may be required,

including provision of safe access, fences, walkways and so on.

• Costs of technical and regulatory compliance, including cost of professional services for

example, architectural and engineering services should be included in overall

considerations.

• Costs of the grid-connection process and costs of equipment that will be needed in order to

connect to installations powered from an LDNSP grid.

• Market availability of equipment of adequate efficiency, quality and reliability such as PV

panel, batteries, inverters, control and monitoring equipment.

• Operation, maintenance, servicing and any other costs.

• PVS life cycle costing assessment. For further guidance refer to T MU AM 01001 ST Life

Cycle Costing.




The life cycle costing analysis shall be broadened by including consideration of revenues

(generated through LDNSP feed-in tariff) and cost savings (cost of energy generated by PVS

that would otherwise be derived from the RailCorp grid). The total energy generated by PVS

shall be compared to what would be spent with the current electricity provider during the same

period. The knowledge of relevant electrical energy tariffs is imperative to understanding the

costs and savings for the energy generated by the following PV systems:

• for systems connected to installations powered from an LDNSP grid, the PV energy

production should be calculated separately of the customer's installation energy

consumption to account for the difference between energy produced by the PV system and

consumed from the grid (net metering), refer to the relevant LDNSP for pricing details

• for systems connected to installations powered from the RailCorp grid, cost of energy

derived from RailCorp electrical network shall take into account peak 7am-9am and 5pm-

8pm on business days, shoulder 9am-5pm and 8pm-10pm on business days, and off-peak

(all times other than peak time and shoulder time) tariff; refer to the operator and

maintainer for pricing details

• estimate as to how will the energy tariffs change once a system is installed, as well as

informed assumptions on energy costs over the lifetime of the installation form part of the

evaluation

Non-financial considerations related to alignment with NSW Climate Change Policy Framework

should be taken into account where appropriate.

6.20. Further design stages Following project approval further design work is required to finalise all details of the system.

Depending on a procurement model, the final design may be carried out as a separate contract,

as a part of a design and build, or other arrangement. Final design of the PVS and network

connection details shall be approved by the EDU, who will consult with others as necessary.

6.21. Alteration to approved design The approved PVS design, settings of the protection devices and control equipment shall not be

modified without informing and receiving prior written authorisation from the EDU.

Upon receipt of a written request to modify the approved design or settings, the EDU will advise

if it is necessary for the requestor to undertake a new assessment of the PVS impact on the

RailCorp electrical network, the timeframe expected to complete a new network study and the

requirements for associated report.




6.22. Critical review process Careful consideration is required to balance the life cycle cost with the requirements of high

quality, safety, reliability and maintainability of system components necessary to operate during

the life of the installation. The project initiator and relevant stakeholders shall review technical

and financial information to select the best option.

The final choice of system configuration and selection of particular equipment shall be

determined through a life cycle costing over a 25 year period (the design life of PV panels), with

considerations including, but not limited to, the following:

• fitness for purpose and technical correctness, based on requirements specified in this

standard

• quality and reliability of equipment used

• compliance with relevant law, regulations, standards and codes of practice

• capital costs, including all costs incurred from design inception to procurement, installation

and commissioning until handover to the operator and maintainer

• operation and maintenance costs of scheduled maintenance including periodic cleaning

and system inspection, an allowance for unscheduled maintenance and cost of disposal at

the end of system life

• renewable energy certificates that offset part of the system costs

• warranty conditions offered for major elements of the system and after sales service

agreements

• compliance with warranty requirements for the design, installation, environmental

conditions and any operational limitations

• any other relevant cost

7. PVS equipment High quality equipment from reputable manufacturers shall be used so that the likelihood of

manufacturer being able to attend to possible problems during the equipment life (for example,

25 years for PV panels) is maximised.

Only CEC approved manufacturers and equipment shall be used.

PVS equipment ingress protection (IP) rating shall be suitable for the prevailing environmental

conditions at the location. Externally mounted equipment IP rating shall be IP 65 or higher in

accordance with AS 60529 Degrees of protection provided by enclosures (IP Code). The IP

rating of individual components for example, PV panel junction boxes shall be increased where

necessary to ensure long term operation of equipment in the location.




7.1. PV panels PV panels shall comply with AS/NZS 5033. All PV module applications shall comply with

IEC 61215-1 Ed. 1.0 (all parts) Terrestrial photovoltaic (PV) modules - Design qualification and

type approval as applicable, and IEC 61730-1 Ed. 2.0 Photovoltaic (PV) module safety

qualification - Part 1: Requirements for construction. The PV panels shall be selected from the

CEC's list of approved PV panels.

PV panels shall have a 0% (or 0W) negative power tolerance. Power tolerance is the actual

range a module can deviate from its maximum power specified under the standard test

conditions (that are laboratory conditions panels are tested under).

PV panels shall come with a minimum 25 year performance warranty assuring at least 80% of

nominal peak power output in the twenty-fifth year.

A minimum of 10 year product, workmanship, installation, and defects warranty is required.

7.2. Panel mounting system The PV panels mounting system shall comply with AS/NZS 1170.1 Structural design actions -

Part 1: Permanent, imposed and other actions and AS/NZS 1170.2 Structural design actions

Part 2: Wind actions and other relevant Australian standards. All system elements shall be

corrosion resistant and designed to withstand applicable static and dynamic (wind) loads. The

system design life shall match the design life of the panels (25 years). The installed panel

mounting system shall be guaranteed for a minimum of 10 years.

7.3. Inverters Solar PV inverters convert the dc electricity generated by PV panels into ac electricity.

Hybrid solar inverters (a multi-mode inverter) can simultaneously manage inputs from both PV

panels and a battery bank, including charging batteries with either PV panels or the electricity

from the grid (depending on which is more economical or preferred). They act as all-in-one

inverter solution for grid-connected solar-plus-storage systems.

Battery inverters manage the charging and discharging of a battery bank (converts dc electricity

into ac electricity, but also does the reverse – converting ac electricity to dc)

High quality inverters shall be used. The inverters shall be selected from the CEC's list of

approved inverters. A minimum 10 year performance warranty is required.

Inverters shall comply with AS/NZS 4777.2, IEC 62109-1 Ed.1.0 Safety of power converters for

use in photovoltaic power systems - Part 1: General requirements and IEC 62109-2 Ed. 1.0

Safety of power converters for use in photovoltaic power systems - Part 2: Particular

requirements for inverters.

Inverter installations shall comply with AS/NZS 4777.1:2016. © State of NSW through Transport for NSW 2019 of 41



Single-phase or three-phase inverters can be used. Three phase installations can be served by

single phase inverters provided that the PV generation in different phases is balanced within

10% (+5% or -5%).

For three-phase inverters, all phases of an inverter shall simultaneously disconnect from or

connect to the network in response to protection or automatic controls (for example,

anti-islanding and subsequent reconnection).

For multiple phase installations where single phase inverters are used, the PVS designer shall

check and ensure that the disconnection or reconnection of an inverter in either one phase or

multiple phases is not going to create network conditions that are non-compliant with the

requirements of EP 90 10 00 02 SP.

Central inverters should be mounted indoors. Inverters shall not be installed in concealed

spaces and cavities. With the exception of electrical rooms, inverters shall not be collocated

with any equipment that is not part of the PVS installation. Inverters serving large installations

should be housed in dedicated rooms. Appropriate means to remove the waste heat generated

by the inverters shall be incorporated in the design.

Inverters mounted in external locations shall be designed to operate outdoors and shall be rated

IP65 or higher. Inverters shall be mounted so they are not exposed to direct sunlight or rain.

PV panel shading could be a consideration in determining the inverter type, as micro-inverters

which are usually installed on the back of PV panels, can help reduce losses related to partial

shading of a PV panel.

7.3.1. Inverter immunity to local supply harmonics The RailCorp LV network contains significant harmonic distortion due to the 6 pulse and

12 pulse traction rectifiers. Refer to EP 03 00 00 01 TI Rectifier Transformer & Rectifier

Characteristics for further information.

PVS inverters shall be equipped with controls that enable satisfactory operation over a variation

in network conditions. The PVS designer is responsible for ensuring that the PVS inverter is

compatible with the supply presented at each respective location and be suitable for full

integration with the power supply grid.

As part of the assurance process, the quality of power supply at each location should be

recorded before and after PVS connection using appropriate recording apparatus. The results

shall form part of the assurance documentation.

7.3.2. Power factor The PVS shall not degrade the installations power factor below 0.90.

Where necessary, inverters shall be equipped with reactive power control to produce both

active and reactive power, that is, an output that is at a non-unity power factor. © State of NSW through Transport for NSW 2019 of 41



7.4. Batteries Storage batteries shall be selected from the list of CEC approved energy storage devices.

The following battery technologies are the most commonly used with PV systems:

• traditional lead-acid and nickel cadmium

• lithium (for example, lithium ion, lithium iron phosphate)

• flow (for example, zinc bromine, vanadium redox flow)

• hybrid ion (for example, aqueous)

The choice of technology can be affected by considerations of the following technical aspects:

• Power rating - the amount of electricity in kilowatts that a battery can deliver at one time.

• Prospective short circuit or fault current - the current during short circuit at the battery

terminals when overcurrent protection does not operate. The prospective short circuit or

fault current should be advised by the manufacturer, and overload protection provided to

match.

• Battery storage capacity - a measure of electrical energy in kWh that a battery can store.

As an example, a battery with a high capacity and a low power rating would be suitable for

delivering a low amount of electricity for a long time. A battery with a low capacity and a

high power rating would be suitable for delivering large amount of energy over a short time.

• Operational suitability - batteries used with PV systems should be able to be 80% charged

or 80% discharged within three hours (time corresponding to the period when highest

energy tariff applies).

• Battery round-trip efficiency - denotes the amount of energy stored as a percentage of the

amount of energy that it took to store it. Usually, a higher efficiency means more economic

value.

• Most batteries need to retain some charge due to their chemical composition. The depth of

discharge of a battery refers to the percentage of a battery’s capacity that can be used for

optimal performance without any danger of damaging the battery.

• Ambient temperature and battery operating temperature.

• Useful life - the battery’s ability to hold a charge will gradually decrease over time. The

minimum requirement is 10 years (with the minimum of 3650 cycles). The end of life

battery energy capacity shall be no less than 70% of a new battery design capacity.

• For some types of batteries, the installation of specific safety equipment, for example an

eyewash station, may be required.




Batteries shall have a warranty that guarantees a specific number of years of useful life and

percentage of original capacity (ability to store energy) available at the end of the guarantee

period and the end of battery life.

Evaluation of the warranties shall be used as additional guidance for battery selection.

7.5. PVS management A PVS that is connected to the RailCorp electrical network shall be equipped with controls as

specified in Section 6.6.1 and Section 6.6.2 that enable satisfactory operation over a variety of

RailCorp electrical network-specific conditions.

7.5.1. PV generation management

PV panels need to be managed by dedicated intelligent controls to optimise panel operation and

achieve as high a power conversion efficiency as possible. The controls shall ensure fast

tracking of the irradiation changes and operation of the PV panels at the maximum power point

(MPP) to optimise energy production. The controls shall monitor energy flows, performance of

major system components and detect malfunctions within the PVS.

The generated output current of the inverter shall be in phase with the utility (RailCorp or

LDNSP) grid voltage. Anti-islanding protection shall immediately shut down the inverter

preventing it from generating ac power when electrical grid power is no longer present.

Energy metering shall measure the total energy production of a PVS and accumulate energy

units in both directions in real-time.

7.5.2. Battery management Battery storage supervisory controls shall ensure optimised energy management, manage the

battery charge controllers and monitor battery charge and discharge profiles. The topology,

configuration and capabilities of a battery management system are dictated by the battery type,

chemistry and battery application.

Battery management systems shall aim at damage prevention and increase of battery life while

balancing battery electrical and thermal management to achieve safe operation while

maintaining the battery in an accurate and reliable state. Measuring, data gathering, calculation,

analysis, intelligent appraisal and resultant action, and means of communication shall be

combined to form a modern battery management system.

7.5.3. Building management and control systems In locations where a building management and control system (BMCS) is available, PVS

controls should be integrated through an agreed interface to the BMCS for remote

management, fault indication, energy readings and other agreed performance data.




Appropriate performance parameters shall be selected, with data from the PV panels and

inverter and battery storage retrieved and processed in real time. Loss of performance shall

generate agreed alarms.

7.6. Wiring and protection Wiring and protection shall comply with AS/NZS 3000 and T HR SS 80002 ST.

PVS wiring shall be accommodated in a separate containment not shared by any other wiring.

Collocation of AC and DC wiring in the same enclosure is not permitted.

External dc wiring shall be ultra violet (UV) protected. In addition, external wiring containment

and its mounting shall safeguard the wiring against the heat from exposure to sun and elevated

temperatures of various building elements (predominantly roofs).

The wiring shall meet the requirements of AS/NZS 3008.1.1 Electrical installations - Selection of

cables – Part 1.1 Cables for alternating voltages up to and including 0.6/1 kV - Typical

Australian installation conditions and Service and Installation Rules of New South Wales, with

specific attention to Section 8.6.

7.7. Labelling Clear labelling and fire services information, including the shutdown procedure, and directions

to the PV panels disconnect devices, inverters and battery storage location shall be provisioned

for emergency services in accordance with section 8.7 of Service and Installation Rules of New

South Wales, section 6 of AS/NZS 4777.1:2016, section 5 of AS/NZS 5033:2014 and Battery

Install Guidelines for Accredited Installers.

Compliance with T HR SS 80002 ST is also required.

The DSMSB shall be labelled with an engraved traffolyte label which reads ‘PVS installed at

<insert location>. The PVS must be shut down and isolated prior to working on this

switchboard’.

Additional labelling requirements may be necessary in complex or unusual installations.

7.8. Documentation PVS isolation procedure shall be provided at the DSMSB to provide specific guidance on the

PVS shutdown procedure to electrical staff.

An operator manual is to be provided for each installation with a hard copy installed in a suitable

holder at the IMSB and inverter location. The operator manual is to contain the information

required in section 5.7 of AS 5033:2014.




8. Installation, testing and commissioning Installation shall be carried out in accordance with Clean Energy Council Install and Supervise

Guidelines for Accredited Installers and Battery Install Guidelines for Accredited Installers.

PVS testing and commissioning shall be carried out as described in Appendix D of

AS/NZS 5033:2014. All work shall be performed by CEC accredited installers in accordance –

Clean Energy Council Install and Supervise Guidelines for Accredited Installers. For systems

with battery storage, the requirements of the Battery Install Guidelines for Accredited Installers

shall also be followed. Testing of the PVS installation shall be in accordance with

AS/NZS 30177 Electrical installations - Verification guidelines.

A testing and commissioning plan including test plans, test methods, detailed test procedures

and protection settings shall be developed for approval of the operator and maintainer at least

three weeks prior to the testing and commissioning taking place.

Prior to the connection of the PVS to the RailCorp electrical network, the EDU will conduct a

mandatory inspection.

An EDU representative shall inspect those parts of the PVS that have an effect on the network

operation, witness the export prevention operation and any other tests as deemed necessary.

On satisfactory completion, the EDU shall approve the installation for connection to the network.

Hard and soft copies, as applicable, of commissioning tests results shall be submitted to

operator maintainer as part of the handover process.

8.1. Performance monitoring To optimise PVS operation management, performance of each system over time shall be

monitored and evaluated periodically with the aid of technical maintenance plans (TMPs).

Remedial action shall be taken when the efficiency of a PVS drops below the calculated

efficiency level expected at the point in time when the evaluation is conducted.

Performance shall be recoded and feedback in the form of an annual report shall be provided

for future reference.

Enhanced monitoring and reporting is required for PVSs with battery storage to facilitate

relevant information on battery storage performance and annualised economic efficiency of the

system.

8.2. Periodic maintenance All maintenance activities shall be recoded. All protection, control systems and equipment

associated with the PVS and its connection to the network shall be periodically tested, in

accordance with an agreed Technical Maintenance Plan developed in accordance with

T MU AM 01008 ST Technical Maintenance Plans and Coding System, to demonstrate correct © State of NSW through Transport for NSW 2019 of 41



operation. The record of all such tests shall be provided to the operator and maintainer with a

certified copy of the test results.

Failure to comply with the testing requirements may result in the operator and maintainer

disconnecting the PVS from the network.

8.3. Decommissioning and disposal At the end of life, all equipment and materials that form a PVS shall not be placed in landfill but

recovered and dispatched to relevant specialist recycling plant. The cost of doing so shall be

included in PVS life cycle calculations.

9. Assurance The PVS assurance process shall comply with the requirements of T HR SS 80002 ST Low

Voltage Electrical Installations.




Appendix A Feasibility study and evaluation methodology guide for PVS installations

Selection of a suitable facility or site where a PVS is to be deployed shall follow the

requirements specified in Section 6 and Section 7. Site specific concerns such as the

geographical orientation and roof inclination of the structures that accommodate PVS

installations have large impact on the ability of a PVS to generate power. The sites that offer the

best yield should be considered as a priority.

Following the requirements specified in Section 6.19, the methodology to be used in the

process shall include the following:

• Establishing the renewable energy target which amounts to matching the PVS size to the

energy requirements (power demand) of the installation and includes an evaluation of how

well the expected PV generation profile (given the number, size, orientation and tilt of PV

panels) matches the installation power demand profile, enabling an estimate of expected

self-consumption of the generated PV energy, and available PV energy surplus (if any).

• Establishing that technical requirements of the proposed PVS installation can be

adequately supported, including roof space and suitability (geographical orientation,

structural fitness), evaluation of what would be the largest solar PVS that could be

installed, and availability of adequate space to accommodate other system components

such as inverters, battery (if used), and so on.

Ability to export to grid can have a major impact on PVS design and cost. If export is not

permitted, in some atypical cases an inclusion of battery storage could be an option.

Figure 3 describes the minimum requirements that shall be addressed.




Estimate PVS peak power and energy kWh generatable by panels in selected location, orientation and tilt during an average summer and winter day

Are the installation energy usage & maximum demand calculations or records available?

Perform relevant calculations or install monitoring equipment over a sufficiently long period to properly

estimate energy usage patterns

No

Determine installation maximum demand (kW) & anticipated energy (kWh) use during peak, shoulder and off-peak times1 During daytime hours (when PVS-generated energy can be used directly)2 Outside daytime hours (unless stored in batteries, PVS-generated energy cannot be used during that period)

Is the installation able to useall generated energy?

No export to grid or battery storage

No Yes

Downsize PVS or export to LDNSP

RailCorp

LDNSP

Is battery storage economically feasible? Yes

Is there other justification? (the installation

will operate at a loss)

No

Yes

Yes

PVS design

Start

Determine orientation and inclination (tilt) of the roof proposed for the accommodation of PV panels. Determine the maximum size & number of PV panels that can be accommodated as set out in Section 6

Is batterystorage

an option?

Downsize thePV system

No

Yes

Abandon process

No

PV panels are able togenerate more energy than the

installation could consumeduring daylight hours

Is export toRailCorp

permitted?

No

Yes


Figure 3 - PVS evaluation methodology

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