the iet solar pv code of practice: what this means for...

The IET solar PV code of practice: what this means for

you Jonny Williams

Director, BRE National Solar Centre Martin Cotterell

Founder and Technical Director, Sundog Energy Chris Roberts

Solar Specialist, STA Griff Thomas

Managing Director, GTEC Training

Part of the BRE Trust

© NSC 2014

IET Solar PV Code of Practice

Introduction Jonny Williams

Part of the BRE Trust

© NSC 2014

IET Solar PV Code of Practice

Martin Cotterell MCS – PV & roofing working groups IEC - TC82 WG3 (co-convenor) British Standards – chair of PV committee

NSC - associate consultant Sundog Energy - founder & director

Why a new document?

First PV specific document released by IET

Previous UK documents only went up to 50kWp

To align with international standard work

New technology

Experience

Why not wait for IEC?

Work underway …

Part 7-712 of IEC 60364 (and BS 7671) Requirements for special installations or locations – Solar photovoltaic (PV) power supply systems. Recent meeting in Birmingham

IEC 62548 Photovoltaic (PV) Arrays – Design Requirements CD of new version recently issued – meeting in December

But slow progress gaining agreement on best approach

Evolution First edition of the “DTI Guide”

2nd Edition published

MIS3002 published - refers to PV guide

MCS PV Guide issued

IET starts work on PV CoP

IET issues CoP for public comment

2002

2006

2007

2012

2013

2014

Scope … “This Code of Practice sets out the requirements for the design, specification, installation, commissioning, operation and maintenance of grid-connected solar photovoltaic (PV) systems installed in the UK. The scope of this Code of Practice covers:

• All parts of a grid-connected solar PV system up to, and including, the connection to the AC mains.

• LV and HV connections and components.

• All scales of application, from small domestic systems to large-scale PV farms.

• Building-mounted, building-integrated and ground-mounted systems.

• Grid-connected systems with battery storage.

• Systems with an open circuit DC voltage of greater than 30VDC and less than 1,500VDC.

Much of the technical content of the CoP is pretty similar to the existing PV Guide

New sections … Large systems

HV connections

Grid connected systems with battery storage

LPS & surge protection

Fire

Much of the technical content of the CoP is pretty similar to the existing PV Guide Headline changes …

Array frame earthing

Earth fault alarm

String fuses

PV plug & sockets

Much of the technical content of the CoP is pretty similar to the existing PV Guide What's NOT included …

MCS scheme requirements

Specific energy estimate procedure

Array frame earthing … It is proposed that the PV array frame will now need an earth connection in most circumstances

Array frame earthing … o Allows DC isolation fault detection systems to operate correctly (provided in most inverters) o Minimises the shock risk due to leakage currents on systems with transformer-less inverters

o Brings the UK in line with the approach taken in most other countries around the world (and IEC standards/documents).

Earth fault alarm … “The Earth fault alarm shall: a) continue to operate until the system is switched off or the fault is

corrected; b) be of a type that can’t be missed (for example, visible/audible signal in

a public area, or SMS message); and c) be accompanied with instructions to the system operator on the need

to immediately investigate the fault.”

More than just an LED on an inverter …

Fault detection + fire prevention

String fuses … Proposed that these will only now be required on one of the active conductors

Plug and sockets … proposed to ban mating of different manufacturer’s / models

This session too short for a comprehensive overview The previous slides … just the headlines This is a draft document, please:

download read comment

Griff Thomas (MD GTEC)

Contract reconciliation Expert witness reports Regulatory compliance audits

The creating of the Code of Practice is nearing completion and comments are due back in by November 7th Once finalised the sector needs to make a decision over how it can best be put to use The question is:


How should the Code of Practice best be implemented in the

sector to ensure that it adds value to contractors and clients?


The implementation in any form should serve to:

Increase safety Standardise installation practices Provide customer / investor assurance Minimise technical barriers to PV

deployment Minimise legislative barriers to PV

deployment (possible ROOFIT access?) Contract reconciliation

Expert witness reports Regulatory compliance audits

As with any technical standard a decision must be made as to how it can be used to best serve the sector concerned As a “Code of Practice” there are a number of options open to the industry broadly as follows:


Optional conformance Contractors may choose to work to the standard and self-declare and promote this to their customers No 3rd party verification is likely to take place unless the customer requests it


Optional conformance with regulatory recognition Contractors may choose to work to the standard and self-declare and promote this to their customers Regulatory bodies are persuaded to recognise conformance to the Code of Practice (OfGEM)


A Stand Alone Certification Scheme A new scheme is created that focusses on the Code of Practice and promotes the benefit of the certificated contractor the industry


An Addition To An Existing Certification Scheme There are a number of “approved contractor” schemes already operation in the sector, consider adding certification to one of these as an option for the contractor and obtain regulatory recognition


The options presented are by no means hard and fast and a number of permutations are possible It is over to the sector to now decide how they feel that the Code of Practice could be integrated to ensure that it adds value to their work


Over to you…………….


the iet solar pv code of practice: what this means for...

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