Quality and Reliability ofPV Power Plants Peeyush Gupta Director – Sales & Marketing UL India Pvt Ltd
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.
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.
Performance of PV Power Plants 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 • Factors Contributing to Performance • Site Selection • Choice of Technology • Plant Design • Quality of Equipment • Installation Practices • Operation and Maintenance US study on average Module degradation per year
PV System Value Chain Project Proposal • Site Lease / purchase • Financial Assessment of DPR. • Return on Capital Investment • Lower P&M costs Operation and Maintenance Financing / Equity • Detailed Project Report • Site assessment and Yield • Distribution, storage • Condition Monitoring • Ensuring plant performance at optimum levels • Modules • Inverters • BoS (Cables, structures etc..) Design of System Final Inspection, Commissioning Engineering Procurement and Construction • Quality checks on installation. • Grid connectivity • System design • Sourcing of components • Installation and commissioning
Quality through Design Modeling techniques used to predict plant performance • 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 Quality & Monitoring Vs. Failure Rate
Quality of System Components • 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 • 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 • 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
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 systems • Verification 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 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.
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.email@example.com www.ul.com\renewable energy