BEST PARCTICES IN SOLAR PHOTOVOLTAICS

Dr. O.S. SASTRYDIRECTOR PV TESTING, SOLAR ENERGY CENTRE,

MINISTRY OF NEW AND RENEWABLE ENERGY, GOVERNMENT OF INDIA

PH. 0124-2579213; Fax: 0124-2579207e.mail: sastry284@yahoo.in

REQUIREMENTS OF BEST QUALITY PV SYSTEMS

• HIGH PERFORMANCE

• SAFETY

• LONG TERM RELIABILITY

• LIFE CYCLE COST (Rs./ kWh) ( GRID PARITY ?)

Best practices solar energy include …. • Programme Planning • Setting Targets (physical, performance and cost

reductions) • Site specific and Need based PV Systems• Use of Standards with Indicators • Growth of Industry: through put & reliability• Creation of high quality testing laboratories • Adoption of latest developments in technology

PHYSICAL:20,000 MW Utility Grid 2000 MW Off- Grid.100MW Roof –Top InstallationsLighting Systems for 20Million Houses

RELIABILITY & LIFE :• 35 years for PV modules?

COST:• Grid Parity by 2020

JAWAHARLAL NEHRU NATIONAL SOLAR MISSION (JNNSM)(TARGETS)

PHYSICAL: 1050 MW Utility Grid 155 MW Off- Grid (Including Roof-top, Lighting, pumps all Off-Grid Systems)

RELIABILITY & LIFE :• 10% in 10 years and 15% in 20 years for PV modules

COST:• Rs. 7- 9/ Wp

JAWAHARLAL NEHRU NATIONAL SOLAR MISSION (JNNSM) (ACHIEVEMENTS)

MAIN PV SYSTEMS / APPLICATIONS • LIGHTING SYSTEMS

- PROTABLE, FIXED HOME LIGHT AND STREET LIGHTING

• PV POWER PACKS

- < 1kWp POWER PLANTS

• STAND ALONE POWER PLANTS

- 1kWp TO 25kWp POWER PLANTS, TELECOMM

• UTILITY SCALE (MW CAPACITY) GI POWER PLANTS- 1MW TO 50MW GI POWER PLANTS

• PV WATER PUMPS - ½ HP TO 5HP AC/DC SURFACE OR SUBMERSIBLE

• OTHER APPLICATIONS- WATER PURIFIERS, GLOW SIGN DISPLAY,

PV Modules : STC PERFORMANCE

- IEC 60904-2 (I-V )- IEC 60891 ( TEMP & INTENSITY CORRECTIONS)

DESIGN QUALIFICATION - IEC 61215 (MON & MULTI CRYSTALLINE SILICON)

- IEC61646( THIN FILM)- IEC 62108( CONCENTRATOR) SAFETY - IEC 61730 (ALL MODULES)

SALT, MIST AND CORROSIVE - IEC 61701

PV STANDARDS ADOPTED FOR PV COMPONENTS AND SYSTEMS

PV BoS SYSTEMS: EFFICIENCY / PERFORMANCE

- IEC 61683 (PCU) - IEC 62093( CHARGE CONTROLLERS & MPPT ENVIRONMENTAL - IEC 60068 2 (1,2,14, 30)

STORAGE BATTERIES - IEC 61427 (ALL TYPE BATTERIES)

- IS 1651 - IS 13369 CABLES, SWITCH/ CIRCUIT BREAKERS/ CONNECTORS - IEC 60947 PART I,II & III- EN 50521- IEC 60189, IS 694, IS1554, IS/ IEC 69947

PV STANDARDS ADOPTED FOR PV COMPONENTS AND SYSTEMS

PV SYSTEMS : Jn. BOXES/ ENCLOSURES

- IEC 2208- IP 65 / IP 21

SPV SYSTEM DESIGN - IEC 62124 INSTALLATION PRACTICES

- IEC 60364 - IEC 61727

NATIONAL ELECTRIC CODES (NEC)

PV STANDARDS ADOPTED FOR PV COMPONENTS AND SYSTEMS

INDICATORS MATTERS..• PV MODULE STC EFFICIENCY • PV ARRAY AND SYSTEM EFFICIENCY • LIFE TIME ENERGY YIELDS (YL)• PERFORMANCE RATIO (PR)• CAPACITY UTILIZATION FACTOR (CUF)• LOSS OF LOAD PROBABILITY (LOLP)• LIFE CYCLE COST (Rs./ kWh) ( GRID PARITY ?)

JNNSM TARGET FOR DEGRADATION: • <10% IN 10 YEARS and <15% IN 25 YEARS

PERFORMANCE INDICATORS OF PV ARRAYS

• YIELD FACTOR = Yf = (kWh/kWp) or (Hours)

Yf = E ( ENERGY OUTPUT)/ Po ( STC DC POWER)

• REFERENCE YIELD Units (Yr) in Hours or kWh/kW

Yr = H ( IN PLANE IRRADIANCE )/ G( 1000W/SQ .M)

• PERFORMANCE RATIO (PR) = Yf / Yr

PR is dimension less, Quantifies Effect of Losses

PR depends on site Temperature, Spectrum & Technology

WHAT ARE OFF-GRID PV SYSTEMS?

LIGHTING SYSTEMS

Components of lighting System

• PV MODULE 3Wp to 74Wp• Storage Battery 12V, 4AH to 100AH (Flood Lead Acid Tubular or VRLA)• Loads: 5 to 13W CFLs OR 2W to 9 W LED• Electronics: - High Frequency Electronics ballast(87%)/ DC-DC converters (95%)

- Charge Controller - Protections

- Indicators • Structures

PV Lighting System Quality Performance (MNRE Specs)

• Conditioning of the System• On-Off Cycles (Endurance Test)• Electronic Efficiency Measurement• Charge Efficiency Measurement• Lumen and LUX Measurement• Uniformity of Light• Quality of Light out put (UV content, Speckle)

PERFORMANCE ASSESSMENT OF LIGHTING SYSTEMS

• Conditioning test• Electronic efficiency test• Charge discharge efficiency

measurement • Protections test• Lumen measurement • LUX measurement• Spectral distribution

measurement of LED • Measurement of view angle

LED AND CFL PERFORMANCE COMPARISON AND SYSTEM REQUIREMENTS

Color recognition

19

SOX lamp

Green-Red LEDs

Residential street

Before 36W TL Now 20W LED

16 lux (meter under the lamp at street level)

8 lux under lamp

The Physiology

21

Scotopic Mesopic Photopic

<0,01 cd/m² |0,001 cd/m² 3 cd/m² | > 3cd/m²

SPV WATER PUMPING SYSTEMS

Quality Testing of PV Water Pumping SystemTYPE OF PUMPS

DC Surface (Centrifugal) Pumps DC/AC Submersible Pumps Float Pumps ?

SPECIFICATIONS IEC 62253 & 61702 AND MNES Performance Guidelines 2006-07

INSTRUMENTATION Deep Sump Well PV Array PV Array Testers Data Loggers with sensors Flow & Pressure Gauges/Meters

Main Quality Indicators Throughput - Liters/watt/day Average Wire to Water efficiency

Peak Efficiency

WHAT ARE THE MAJOR CONCERNS ?

• MAIN PROBLEMS ARE :

- MATCHING OF PUMP AND PV ARRAY

- EFFICIENCY OF MOTOR AND PUMP

- PV ARRAY STRUCTURES

- PROTECTIONS ( DRY RUNNING, GROUNDING, DC SHOCK etc.)

BATTERY TESTING

Quality Assessment of Batteries• IEC 61427• IS 1651, IS 13369, • JIS 8709• PERFORMANCE TESTS - Capacity Test at C/10 or C/20 rate - Shelf Life - Cycle Life vs. DoD - Charge Efficiency - Temp. Coefficients fully computer - Spill Proof Features

WHAT ARE THE MAJOR PROBLEMS ?

• MAIN PROBLEMS ARE : - WRONG INSTALLATIONS (MODULE, STRUCTURE & CABLES) - POOR COMPONENTS LOW WATTAGE MODULE AND BATTERY POOR DESIGNS, POOR ELECTRONICS

- SYSTEM SIZING PROBLEMS ? (CONNECTION OF ADDITIONAL LOADS)

TO ENSURE THE QUALITY OF SUPPLIED SYSTEMS:

• A THREE STEP APPROCH FOLLOWED BY IEC TO ENSURE QUALITY

- TESTING OF PROTO-TYPE

- QUALITY TEST DURING MANUFACTURING

- QUALITY TEST OF PRODUCT FROM THE MARKET

SPV POWER PLANTS

OFF-GRID PV POWER PLANTS

• Stand Alone• Hybrid

COMPONENTS SPV POWER PLANTS

1. SPV Modules2. Batteries3. Inverters4. Charge Controllers5. Loads CFLs, Pumps, Motors, Refrigerators etc.6. Structures

STANDARDS FOR STAND ALONE POWER PLANTS

• Standards for POWER PLANT Components ( PERFORMANCE, DESIGN QUALIFICATION AND ENVIRONMENT)

- PV MODULE –IEC 61215, 61646, 62108- BATTERY – BIS , IEC (NO QUALIFIED SUPPLIER?) - INVERTER IEC-61683 ( VERY FEW INDIAN SUPPLIERS!!) , - CHARGE CONTROLLER& MPPT –IEC 62093

• Design Verification IEC - 62124• INSTALLATION AND SAFETY IEC- 62548 IEC – 61173 (OVER VOLTAGE PROTECTION) NATIONAL ELECTRIC CODE FOR SYSTEM AND EQUIPMENT GROUNDING• Performance Monitoring, DATA exchange IEC – 61724• I-V CHARACTERISTICS OF PV ARRAY ON SITE MEASUREMENT IEC- 61829

ENVIRONMENTAL TESTS STANDARDS FOR ELECTRONICS

• OPERATIONAL CONDITIONS DIVIDED IN TO FOUR GROUPS- INDOOR CONDITIONED - INDOOR UN-CONDITIONED- OUTDOOR CONDITIONED - OUT DOOR UN-CONDITIONED

• IEC STANDARDS - 60068-2-1 (COLD TEST -10°C ±3°C FOR 2 HOURS) - 60068-2-2 (DRY HEAT TEST 55°C ±2°C FOR 16 HOURS) - 60068-2-14 ( TEMPERSTURE CYCLING -5°C TO 55°C ±3°C FOR 5 CYCLES) - 60068-2-30 (DAMP HEAT STUDY STATE 25°C TO 40°C ±3°C AND 93% RH 12+12 Hrs, 2Cycles)

• IEC STANDARD FOR INGRESS PROTECTION (IP) - IP 21 FOR HOME LIGHTS/ LANTERNS - IP 54/ IP64 FOR STREET LIGHTS

PERFORMANCE TEST STANDARDS FOR INVERTERS

• IEC STANDARDS - 61683 • EFFICIENCY OF PERFORMANCE of STAND ALONE INVERTERS (at unity and .25PF)

- 10% LOAD - 25% LOAD - 50% Load- 75% Load- 90-100% Load

• - EFFICIENCY OF PERFORMANCE OF CHARGE CONTROLLER AND MPPT ( - IEC 62093 ( PERFORMANCE TEST, PROTECTIONS, etc.)

• INSTALLATION AND SAFETY FOR OFF-GRID SYSTEMS - IEC 62548 ( SYSTEM VOLTAGE, GROUNDING, RATING OF CONTROL DEVICES, etc.)

ENVIRONMENTAL TEST STANDARDS INVERTERS, CHARGE CONTROLLERS AND MPPTs

• OPERATIONAL CONDITIONS DIVIDED IN TO FOUR GROUPS- INDOOR CONDITIONED - INDOOR UN-CONDITIONED- OUTDOOR CONDITIONED - OUT DOOR UN-CONDITIONED

• IEC STANDARDS - 60068-2-1 (COLD TEST -10°C ±3°C FOR 2 HOURS) - 60068-2-2 (DRY HEAT TEST 55°C ±2°C FOR 16 HOURS) - 60068-2-14 ( TEMPERSTURE CYCLING -5°C TO 55°C ±3°C FOR 5 CYCLES) - 60068-2-30 (DAMP HEAT STUDY STATE 25°C TO 40°C ±3°C AND 93% RH 12+12 Hrs, 2Cyc)

• IEC STANDARD FOR INGRESS PROTECTION (IP) - IP 21 FOR INDOOR INVERTERS ( IN -DOOR CONDITIONED)

Quality Checks Of PV Power Plants• Standards/Specifications

IEC, & IEEE Standards Inspection Criteria

• Performance Indicators Energy Yields ( Yi = kWh/kWp )

Performance Ratio (PR= Yi/ Rf) LOLP

Plant capacity factor/ Plant Utility Factor• Instrumentations

Array TestersData Acquisition Systems (DAS)Current Voltage Power TransducersBattery SOC TestersLoads

Data Contents of SPV Power Plant

WHAT ARE THE MAJOR QUALITY CONCERNS?

• MAIN PROBLEMS ARE : - WRONG DESIGNS ( SELECTION OF PV ARRAY, BATTERY BANK, INVERTER & LOAD)

- BATTERY RELATED PROBLES ( REDUCED LIFE SPAN)

- POOR INSTALLATIONS

- GROUNDING ( SYSTEM, EQUIPMENT AND LIGHTNING ARRESTERS)

- SHADOWING

- CERTIFICATION OF COMPONENTS

- MATCHING OF PV ARRAYS, MPPT RANGE, BATTERY BANK & INVERTER

WHO ARE QUALIFIED TO CERTIFY?

WHAT ARE THE REQUIREMENTS FROM THE LABS?

• REQUIREMENTS ARE :

- NABL or EQUIVALENT ACCREDITATION

- PART OF THE REQUIRED TEST EQUIPMENT

- MANPOWER

- INDEPENDENT TEST LABORATORY PREFERRD

AUTHORISED TEST CENTRES IN INDIA

• SEC PV MODULES, BATTERY , LIGHTING SYSTEMS (PERFORMANCE ONLY), WATER PUMPS & INVERTERS

• OATCs ERTL (KOLKATA) – BATTERIES, LIGHTING SYSTEMS & INVERTERS ETDC ( BANGALORE) – PV MODULES, BATTERIES AND INVERTERS CPRI ( BANGALORE) - BATTERIES, LIGHTING SYSTEMS (CFL), INVERTERS • ADDITIONAL CENTERS FOR PV MODULES TUV AND UL BANGALORE

• ADDITIONAL CENTERS FOR BATTERIES CECRI OR ANY OF THE NABL CERTIFIED

• NABL ACCREDITED ADDITIONAL CENTERS FOR IELECTRONICS , LIGHTING SYSTEMS , NVERTERS & MPPTS

ETDC (Bangalore), UL, TUV, INTER TEK (Noida), ERTL (kolkata), ETDC Pune, ETDC Maholi and ETDC (G)

• ALL TESTING LABS WITH NABL ACCREDITATION FOR ENVIRONMENTAL , MECHANICAL & IP TESTS ARE APPROVED

QUESTIONS ??

THANK YOU FOR YOUR ATTENTION!!