1/30 TASK 13: PERFORMANCE AND RELIABILITY OF PV SYSTEMS Quality Assessment of PV systems by Analysis of System Performance Wilfried van Sark (Utrecht University) Thomas Nordmann (TNC), Panos Moraitis (UU), Bhavya Kausika (UU) IEA-PVPS-Task 13 side event Intersolar 2015 PV Module Reliability and System Performance Analysis 9 June 2015, Munich, Germany
2/30 Content Motivation Work from IEA-PVPS-Task 13 Performance database (small sample) Statistical analysis (large sample) Counting the Sun campaign Conclusion
TOP 3 MARK IEA INTERNATIONAL ENERGY AGENCY 3/30 Motivation PV is becoming a mainstream 2014 energy harvesting option 177 GWp power, end 2014 Optimal performance required But, do we know How well is PV serving the world? Do good promises lead to good performance (= quality)? As of the end of 2014 177GW Have been installed all over the world and only in 2014 38,7 GW Have been installed in the world IEA PVPS countries 1% IEA PVPS COUNTRIES WITH MORE THAN 1 GW INSTALLED South-Africa India UK Chile Global PV Evolution IEA PVPS COUNTRIES WITH LESS THAN 1 GW INSTALLED 20 countries have now passed the 1GW of cumulative PV systems capacity at the end of 2014 and 5 countries installed at least 1 GW in 2014 (compared to 9 in 2013). IN 2014 THE TOP 3 WORLD COUNTRIES, WHICH ARE ALSO PART OF THE IEA PVPS PROGRAM WERE: 1 2 OF THE WORLD ELECTRICITY GENERATION IS NOW COVERED WITH PV AND 19 COUNTRIES IN THE WORLD NOW HAVE AT LEAST ENOUGH PV TO COVER 1% OF THEIR ANNUAL ELECTRICITY DEMAND WITH PV. 3 NON IEA PVPS COUNTRIES WITH A SIGNIFICANT PV MARKET 7,9% 7,6% ITALY GREECE 7,1% GERMANY
Current (A) [Pannebakker, 2014] IEA INTERNATIONAL ENERGY AGENCY 4/30 Motivation Shade is one reason for lower performance (inverter MPP) 8 7 6 5 Netting, row shade no shade 3 BPD 6 BPD 12 BPD 20 BPD 60 BPD 4 3 2 1 0 0 5 10 15 20 25 30 35 Voltage (V)
[Woyte, 2014] IEA INTERNATIONAL ENERGY AGENCY 5/30 Monitoring Data: What to Measure? G I V DC I DC P DC V AC I AC P AC PV array Inverter Grid T amb, T mod, S W y r Reference yield y A Array yield y f System yield I C Array capture losses I S System losses PR
6/30 Field performance analysis Analytical approach: collecting and analyzing validated datasets in public database are contributed by all participants (e.g., monthly PR) Statistical approach: collecting huge amounts of system data by using web scraping techniques followed by analyses.
Quality Control www Interface user interface IEA INTERNATIONAL ENERGY AGENCY Performance Data Base T13/2.1/ Topology (10-2011 - 2017 ) Task 13/2.1 T13 Expert database input tool, since: 5-2011 T13 partner database input tool, online since: 10-2011 mail mail mail Operator T13/1 www www 7/30 direct www access with browser Export numeric info plant, several monitoring years graphic infos XY Info evaluation Master DB
8/30 Screen shot input tool
www.iea-pvps.org 9/30 http://www.iea-pvps.org PVPS Performance Data Base
Example of automated analysis in the DB 10/30
11/30 Analysing groups of PV systems using filter criteria Performance improved
12/30 Analysing groups of PV systems using filter criteria
13/30 Performance ratio is going up IEA PVPS Task 2 [Nordmann, 2007] PR from ~60% to >80% [Reich, 2012] 90% max?!
14/30 Motivation Performance has been increasing in the past decades Still, reasons for lower performance than expected (or promised) are difficult to detect due to insufficient monitoring in particular 1-5 kwp residential systems
15/30 Statistical approach data per system size bins (<1 kwp -- >10 MWp) supplied per region/country: Annual Yield (AC) kwh/y/installed kwp as a function of location, climate zone Annual average performance ratio PR Use measured irradiance from local sensor or satellite data Degradation rate For plants in the field for a 5-year period (if possible) Focus on annual data is what the customer needs to know
16/30 Example: Statistical analysis Italy Example size bin: 10-100 kwp, installed in 2007, full year measurements for 2008-2012 (5 years) Courtesy: Francesca Tilli (GSE) [T13 participant]
17/30 Italy All years averaged Larger systems somewhat better performing # systems North: 58 Central: 48 South: 48
18/30 Statistical analysis: Data mining Market is introducing web tools for system owners to share monitor data, e.g., SolarLog Objective is to analyze PV performance data obtained by web scraping techniques that collect and organize these data automatically in databases What you see, is what you can extract [Legal] Developed Python scripts Accuracy?
19/30 Country Samples System Size kwp Results Netherlands 728 11.1 Germany 764 15.6 Italy 532 13.1 France 325 15.1 Belgium 565 6.5 GER ITA NL FRA BEL P M A
2011 2012 2013 IEA INTERNATIONAL ENERGY AGENCY 20/30 Results Yearly variation between 2011-2013 from 2-11% NL GER BEL ITA FRA
21/30 FRA GER ITA South: +6-18% Annual yield (kwh/kwp) ±(stdev) Country 2011 2012 2013 Germany France Italy North 979±153 937±126 882±109 South 1081±154 1044±121 992±125 North 1030±362 993±201 959±154 South 1099±96 1092±224 1103±166 North 1219±170 1177±157 1094±148 South 1352±113 1337±199 1288±203
22/30 Results: NL Geographical Variation Region PR Annual Yield kwh/kwp Irradiation kwh/kwp Coast 79.3+/-2% 895+/-21 1165 Mainland 77.1+/-2% 833+/-19 1021 Temperature, wind?
Annual yield 2014 IEA INTERNATIONAL ENERGY AGENCY 1000 kwh/kwp Netherlands 23/30 Belgium Germany France Italy To be presented at IEEE PVSC 42, New Orleans, 14-18 June 2015
24/30 GIS mapping of yield 2014
in progress 25/30
26/30 Counting the Sun Dutch Solar Days 2014 (May 12 May 18) Awareness campaign How well is my system doing Social media, national television show Kassa >5000 systems spread over the country citizen science weekly yield average 33.4 kwh/kwp
27/30 Counting the Sun Most systems are performing well Average performance ratio 0.74±0.10 NO geographical variation in performance ratio Some 10% of participants indicated some form of shade, performance ratio: 0.70±0.10. irradiation yield performance ratio
28/30 Conclusions Obviously, without DATA one cannot say anything about PERFORMANCE (=quality) Reliability? = continuously high PR IEA PVPS Task 13 Collecting and analyzing data From participants Statistical analysis, web scraping Irradiation data needed (JRC) Please join!
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30/30 Thank you for listening! Q&A http://www.iea-pvps.org/index.php?id=57
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32/30 Reports by IEA PVPS Task 13 http://www.iea-pvps.org/index.php?id=57 1. Review of Failures of Photovoltaic Module, Report IEA-PVPS T13-01:2014 2. Analytical Monitoring of Grid-connected Photovoltaic Systems - Good Practices for Monitoring and Performance Analysis, Report IEA-PVPS T13-03: 2014 3. Characterisation of Performance of Thin-film Photovoltaic Technologies, Report IEA- PVPS T13-02:2014 4. Degradation Behaviour of PV Modules under Different Accelerated Stress Conditions Based on Stress Conditions Evaluated from Real-time Outdoor Testing, Report IEA- PVPS T13-04: 2014 5. Analysis of Long-Term Performance of PV Systems - Different Data Resolution for Different Purposes,, Report IEA-PVPS T13-05:2014