© 2011 Underwriters Laboratories Inc.

Quality and Reliability ofPV Power Plants

Peeyush GuptaDirector – Sales & MarketingUL India Pvt Ltd

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SPV – heralding a new future in Sustainability• With abundant solar cover in India, the potential

of Energy Self-reliance is immense• SPV is roughly 1% of India’s Installed energy

capacity of 200GW – but the potential is much higher.

• Phase – 2 of JNNSM vital to meet RE targets• With 16-18% T&D losses, insufficient Grid

connectivity and high cost of land acquisition, Off Grid PV could be the answer to the energy deficit – but poses fresh challenges in safety and reliability.

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Trends and studies in the PV industry• Policy incentives fuelled 33GW of

capacity expansion in 2012.• Cost of power fast approaching Grid-

parity levels.• Module prices dropped by over 56%

since 2011, drop continues.• Maximizing cell efficiency and system

yield are priority areas of technology. • Safety, Quality and reliability concerns

rising: Fire and Electrical shock concerns,

particularly in Roof-Top systems Overall efficiency of PV systems. Module performance and degradation Bankability of PV systems : guaranteed

returns over the entire lifetime of the system.

• Cables, connectors, and Junction Boxes highly prone to failure.

• Urgent need to create confidence in market on long-term viability of the technology.

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Performance of PV Power Plants

Factors Contributing to Performance Site Selection Choice of Technology Plant Design Quality of Equipment Installation Practices Operation and Maintenance

CUF based on plant data from Gujarat (January to April 2012)

JNNSM – Phase1 Batch 1 – 20 X 5 MW = 100 MW

Highest CUF – 26.67%Highest Net Exported Power – 987,731 KWh

Lowest CUF – 17.88%Lowest Net Exported Power – 659,600 KWh

US study on average Module degradation per year

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PV System Value Chain

Project Proposal

Financing / Equity

Design of System

Engineering Procurement

and Construction

Final Inspection, Commissio

ning

Operation and

Maintenance• Detailed Project Report• Site assessment and

Yield

• Modules• Inverters• BoS (Cables,

structures etc..)

• Site Lease / purchase• Financial Assessment

of DPR. • Return on Capital

Investment• Lower P&M costs

• System design• Sourcing of

components• Installation and

commissioning

• Quality checks on installation.

• Grid connectivity

• Distribution, storage• Condition Monitoring• Ensuring plant

performance at optimum levels

Quality through Design

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Planning and Engineering Site Assessment Assessment of Environmental Conditions PV plant layout and calculation of shade Assessment of module technology options Review of Technology Selection Criteria Electrical cabling Civil structures Control and instrumentation Power evacuation Review of conceptual plant design(s) and

technical description / specification of components

Energy yield estimate Monitoring & Control Project financial model appraisal ‘IEC62446 : Requirements for system

documentation, Commissioning Tests and Inspections’ can be used as a guideline

Modeling techniques used to predict plant performance

Quality & Monitoring Vs. Failure Rate

Quality of System Components

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PV Module – Fire safety and performance Intended performance of cells and PV

panels, Hot spot, performance in harsh environment conditions.

Module tests as per IEC61215, IEC 61730, UL1703, IEC61646, IEC61701,

PV Inverter – Performance Issues Efficiency, Failure of Components Central Inverter Vs String Inverters Inverter tests as per IEC61683, UL1741,

IEC60068, IEC 62109 and EN 50178.

BoS – Quality and Reliability Flammability, corrosion and ingress protection, prevention of electrical shock and

protection of faults Combiner box as per UL 50, UL50E, IEC62208. Circuit Breakers type tests as per UL/IEC 60947, EN50521 Cables as per IEC60189, UL 4703. Counterfeit products – how do we safeguard ourselves?

Commissioning and Post Commissioning Checks

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Reliability of PV modules Accelerated stress tests to determine MTTF

in actual use. Performance of PV modules at High

Temperatures and low irradiance as per IEC61853-1.

Potential Induced Degradation (PID tests) Reliability vs. Durability vs. Failure

Commissioning Checks As per IEC62446 for Grid Connected systems IEC62124 for Design verification of stand-

alone PV power plants. Installation checks as per local electricity

codes; training of installers.

Post Commissioning Periodic Verification of Power Plant

Performance Ratio (PR). Condition Monitoring and System Checks. On-Site PIV measurements

Performance of PV Installations

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Major Safety Issues

• A robust mechanism of component type testing and installer training is required to ensure operator and consumer safety

• Roof top systems pose an immense challenge in terms of consumer safety – primarily fire and shock.

Ensuring Quality and Reliability of PV systemsVerification of Design, Sourcing Detailed Project Report

Bid Evaluation

Review of Vendor drawing- post E P C Award

Monitoring & Supervision of activities during Erection & Commissioning

Quality Inspections

Verification of Solar Installation and Performance Energy Yield Estimation and

comparison with that of E P C

Design Specification and documentation Vetting

Installation Process

Post Installation process

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An Independent verification by a 3rd party provides higher confidence to the project developers and financial community that the PV Power Plant is designed, built and

commissioned according to internationally accepted standards and meet the requirement of local electric codes.

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Summary and Next steps• The importance of Solar Energy to meet the

energy needs of India is unquestionable.

• The PV eco-system is a complex one with several stakeholders – its critical to involve all stakeholders to ensure Quality.

• At the policy level, standards / regulations are necessary to ensure Quality and Reliability and to bring confidence into this technology.

• Independent verification of contracts and installations can ensure quality.

• Failure Analysis including maintaining a central database.

• Adapting standards to real-time field conditions.

• Development of a ‘Reliability Scorecard’ for the PV systems installed.

High Quality, Safe and Reliable Solar Systems… Need of the Hour

THANK YOU.

Peeyush.gupta@ul.comwww.ul.com\renewable energy