Transcript Performance evaluation technology of photovoltaics for certification & calibration Kengo Morita

Performance evaluation technology of
photovoltaics for certification & calibration
Kengo Morita
TÜV Rheinland Japan Ltd.
Solar Energy Assessment Center (SEAC)
4-5-24 Chigasaki-higashi, Tsuzuki-ku,
Yokohama 224-0033, Japan
Tel: +81-45-271-3508
Direct: +81-45-914-0439
Fax: +81-45-271-3525
email: [email protected]
http://www.tuv.com
No part of this presentation may be reproduced in any form or by any means without the permission from
TÜV Rheinland Japan - Photovoltaic Department.
TÜV Rheinland Japan Photovoltaic Department
2009-10-15
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Outline
* About us
* Importance of performance evaluation
* General concept for performance evaluation of PV
modules
* Our facilities for the performance measurement
* Measurement technique of
- Single amorphous
- Multi junction (ex; a-Si / μc-Si)
- CIS
* Future Plan
TÜV Rheinland Japan Photovoltaic Department
2009-10-15
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About Us
• Established as a pressure vessel inspection
organization we have been offering international safety
and system management certification for over 130 years.
People
Technology
TÜV Rheinland Japan Photovoltaic Department
2009-10-15
Environment
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Industries served by the TÜV Rheinland Group
Automotive Industry
Primary Industry
Construction & Real Estate
Railway/Track-Based Systems
Health
Banks & Insurance Companies
Aviation and Airports
Consumer Goods Industry
Energy Industry
Capital Goods
Leisure Time Industry
Suppliers
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Our activity in PV field
- PV module certification program
*IEC 61215 and IEC 61730 – Crystalline
*IEC 61646 and IEC 61730 – Thin Film
*Factory inspection
- Calibration & Measurement Services of Photovoltaics
- Type approval of PV module components
Accreditations
Our testing laboratory conforms to ISO/IEC 17025:2005
- IECEE CB Accreditation
- JNLA & ASNITE Accreditation by IA Japan
- DATech Accreditation by DAR (Germany)
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SEAC (Solar Energy Assessment Center)
Opened in Yokohama city
on 2009/6/15
The SEAC provides evaluations of the Thin Film Modules and Calibration Services.
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Importance of performance evaluation
Simplified test sequence of certification program (IEC61215, 61646)
Visual inspection, power determination, insulation test (dry and wet)
Electr.
properties
UV
preconditioning
Outdoor
exposure
Thermal
cycling (TC50)
Bypassdiode test
Humidity
freeze test
Hot-spot
test
Robustness of
terminations
Damp
heat test
Mech.
load test
Thermal
cycling (TC200)
Hail
impact
Light-soaking  only IEC 61646
Visual inspection, power determination, insulation test (dry and wet)
TÜV Rheinland Japan Photovoltaic Department
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Importance of performance evaluation
Certification testing
Simplified pass criteria regarding performance
- For crystalline Si (IEC61215)
* Degradation rate of each test < 5%
* Degradation rate of each sequence < 8%
- For thin-film (IEC61646)
* Pmax at STC after light soaking > 90% of Pmax of min_value
specified by manufacturer
Calibraton testing
Measured module is used as reference module for
measurement control of production line
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General concept for performance evaluation
1. Relevant standards
* IEC60904-1 (IV measurement method)
* IEC60904-2 (Reference cell & module
with calibration method)
* IEC60904-3 (Measurement principles
with reference spectral irradiance data)
* IEC60904-4 (Traceability)
* IEC60904-7 (Computation of the spectral mismatch
correction)
* IEC60904-8 (spectral response measurement method)
* IEC60904-9 (Requirement of solar simulator)
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General concept for performance evaluation
2. Standard test condition (STC)
* Irradiance: 1kW/m2
* Spectral irradiance
distribution: AM1.5 G,
Reference spectrum
* Temperature: 25℃
Spectral irradiance (W/m2/nm)
1.8
IEC60904-3,Ed.1
IEC60904-3,Ed.2
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
300
500
700
900
1100
Wavelength (nm)
Reference spectral irradiance (AM1.5G)
Reference spectral irradiance is determined by IEC60904-3.
The performance of photovoltaics should be measured
based on standard test condition.
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General concept for performance evaluation
3. Reference solar cells
mono-Si
multi-Si
a-Si
Spectral Response
1.0
0.8
0.6
0.4
0.2
0.0
300
Photograph of reference solar cell
500
700
900
Wave length(nm)
1100
Spectral response of some kind of
general photovoltaics
The spectral response of reference solar cell should be
similar to tested sample. Otherwise spectral mismatch
error is induced.
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General concept for performance evaluation
4. Spectral mismatch evaluation
What is spectral mismatch error ?


Φm  λ Q1  λ dλ Φs  λ Q2  λ dλ 

  100
Spectral mismatch (%)   1


Φs  λ Q1  λ dλ Φm  λ Q2  λ dλ 






ΦS (λ) ：Reference spectral irradiance
Φｍ (λ) ：Spectral irradiance of used solar simulator
Q１(λ) ：Spectral response of reference solar cell
Q２(λ) ：Spectral response of tested sample
(IEC60904-7: Computation of the spectral mismatch correction for
muasurement of photovoltaic devices)
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Our facilities for performance evaluation
1. Photo of solar simulator
Long pulse solar simulator (LPSS)
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Our facilities for performance evaluation
2. Specification of LPSS
・ Available test area: 2.0×1.4m
・ Class AAA in accordance with IEC60904-9 Ed.2
- Spectral irradiance: Air Mass 1.5G, Variable type
<±25% according to IEC60904-9
- Non-Uniformity: <±2.0% (Class A)
- Stability of Pulse: within ±2.0%
・ Maximum pulse duration: 800msec
・ Lamp: 6 Xenon short-arc lamp (5kW)
・ Accuracy of current & voltage measurement: <±0.2%
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Our facilities for performance evaluation
3. Measurement data of Non-Uniformity (%)
Check every month
TÜV Rheinland Japan Photovoltaic Department
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140*100cm
Max
1.9
Min
-0.8
±
1.1%
200*140cm
Max
1.9
Min
-1.2
±
1.5%
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Our facilities for performance evaluation
4. Measurement data of Spectral match
Match to crystalline Si (IEC/JIS)
SS
AM1.5G Ed.2
250
Irr [uW/cm2/nm]
200
150
wavelength
400-500
500-600
600-700
700-800
800-900
900-1100
Sum
AM1.5G
SS mismatch(%)
18.4
18.8
2.4
19.9
19.7
-1.2
18.4
17.9
-2.2
14.9
15.0
0.6
12.5
13.0
4.3
15.9
15.5
-2.6
100.0
100.0
100
Match to amorphous Si (JIS)
50
0
300
400
500
600 700 800
wavelength[nm]
900 1000 1100
Spectral irradiance of solar simulator
Check every month
TÜV Rheinland Japan Photovoltaic Department
2009-10-15
wavelength
350-400
400-450
450-500
500-550
550-600
600-650
650-700
700-750
Sum
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AM1.5G
SS mismatch(%)
6.2
6.4
3.2
11.8
11.8
-0.5
14.9
15.4
3.5
14.6
14.3
-2.5
14.3
14.1
-1.1
13.8
13.2
-4.0
12.9
12.7
-1.6
11.5
12.1
5.4
100.0
100.0
Our facilities for performance evaluation
5. Measurement data of Temporal instability
Sample Isc after irradiance correction
(Sample Isc / measured irradiance
by reference range)
(Measured Isc / calibrated Isc)
1.02
Irradiance (kW/m2)
1.015
Isc after Irradiance correction
Irradiance during 1 pulse
1.02
1.015
1.01
1.005
1.01
1.005
1
0.995
1
0.995
0.99
Isc measured by sample range
Isc measured by reference range
0.985
0.98
0
50
100
150
200
250
0.99
0.985
0.98
0
50
TÜV Rheinland Japan Photovoltaic Department
2009-10-15
150
200
250
Time (msec)
Time (msec)
LTI = ±0.9%
100
Accuracy of irradiance correction = ±0.1%
(This is the concept of STI)
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Our facilities for performance evaluation
6. Measurement procedure
1. Check of spectral response of the tested sample
to be measured
2. Spectral mismatch evaluation (IEC60904-7)
3. Set of the tested sample and reference cell
(Reference cell should be set at the position of average
irradiance in the area of tested sample.)
4. Temperature control (tested sample and reference cell)
5. Check of sweep direciton and sampling speed
6. Adjustment of irradiance
7. Measurement of current and voltage of the tested sample
& irradiance (current of reference cell) at same time
during sweeping voltage, 250point, repeat time: 3)
8. Data analysis
TÜV Rheinland Japan Photovoltaic Department
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Our facilities for performance evaluation
7. Uncertainty
Isc: 2.0%
Voc:1.1%
Pmax:2.3%
(coverage factor k = 2)
TÜV Rheinland Japan Photovoltaic Department
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Our facilities for performance evaluation
8. Measurement Reproducibility of Pmax, Isc
by our measurement system during 6 months
Isc: 0.2% (2σ）
1.05
1.05
1.04
1.04
1.03
1.03
1.02
1.02
Normalized Isc
Normalized Pmax
Pmax: 0.6% (2σ）
1.01
1.00
0.99
0.98
1.01
1.00
0.99
0.98
0.97
0.97
0.96
0.96
0.95
1-Apr-09
0.95
1-Apr-09
1-Jun-09
1-Aug-09
1-Oct-09
1-Jun-09
Measurement Day
Measurement Day
Sample: mono-crystalline Si, 1.6×1.0m
TÜV Rheinland Japan Photovoltaic Department
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1-Oct-09
Example of Test Report of IV measurement
DAT-PL-069/09-30
ASNITE 0034T
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Measurement technique for thin-film type
Results from the Second International
Module Inter-comparison
S. Rummel et al., 2006 IEEE 4th World Conference on Photovoltaic Energy Conversion (WCPEC-4) held May 7-12,
2006 in Waikoloa, Hawaii
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Measurement technique for thin-film type
1. single amorphous
Reference solar cell: Pseudo amorphous reference cell
Filter folder
Optical Filter
Air
Glass
Air
c-Si cell
Base
Additional filter type
Optical Filter
Optical Filter
Air
c-Si cell
Encapsulant
c-Si cell
Base
Base
Identification type
encapsulated type
Structure: Crystalline Si with optical filter which spectral response is
similar to tested amorphous cell)
Spectral mismatch evaluation
TÜV Rheinland Japan Photovoltaic Department
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Measurement technique for thin-film type
1. single amorphous
1.02
Solar simulator
lens
Reflection light
Incident light
Normalized Isc
1.00
0.98
0.96
0.94
0.92
Re-reflection
Ref Cell
Additional filter type
Identification type
Encapsulated type
Amorphous
Cosine law
0.90
-6 -5 -4 -3 -2 -1 0 1 2 3
Incident light angle (°)
4
5
6
Light angle characteristics of reference cells
Irradiance measurement error is induced by multireflection. One of solution is structure of reference cell.
TÜV Rheinland Japan Photovoltaic Department
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Measurement technique for thin-film type
2. Multi-junction
・Double junction consists of top cell (ex:a-Si) and bottom cell
(ex:thin film c-Si) with difference range of spectral response
・Series connected structure (Top+Bottom)
Spectral response of top cell and bottom cell of multi (double) junction cell
TÜV Rheinland Japan Photovoltaic Department
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Measurement technique for thin-film type
2. Multi-junction
Tandem modules are series connected structure
The current of the module is limited to the current of the
cell with the lower Isc (Top or Bottom)
IV characteristic of the module strongly depends on the
spectral irradiance distribution of the light source.
It is more difficult to evaluate STC performance than that
of single junction cell
TÜV Rheinland Japan Photovoltaic Department
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Measurement technique for thin-film type
2. Multi-junction
Spectral dependence characteristics of multi-junction cell
IV characteristic of the multi-junction cell strongly depends
on the spectral irradiance distribution of the light source.
Source: Fraunhofer ISE
TÜV Rheinland Japan Photovoltaic Department
2009-10-15
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Measurement technique for thin-film type
2. Multi-junction
Measurement procedure for double-junction
1. Measure spectral response of top and bottom cell (tested
sample)
2. Make 2 reference component cells used by stable crystalline
Si cell with proper optical filter based on spectral response
data of tested sample.
3. Measure spectral response of 2 reference component cells
4. Confirm that these reference cells are relatively equivalent to
that of tested sample (Spectral mismatch evaluations)
5. Calibrate each reference cell in accordance with IEC60904-2
6. Measure IV characteristic of tested sample at the condition
that irradiance level measured with each reference
component cell is 1 Sun (kw/m2)
(This condition is equivalent to AM1.5G for double-junction)
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Measurement technique for thin-film type
3. CIS
Spectral response of CIS and crystalline-Si
Reference solar cell: Crystalline-Si
Need spectral mismatch correction
http://www.showashell-solar.co.jp/index.html
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Measurement technique for thin-film type
3. CIS
Light soaking effect, annealing effect of CIS solar cell
Preconditioning should be determined before
performance measurement
http://www.tech.nedo.go.jp/
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Future plan
-Calibration of secondary reference cell & module
- Research for Performance evaluation method
* Proper structure of reference device for amorphous &
multi-junction
* Spectral adjustment technique for multi-junction
* Proper preconditioning for CIS
* New method for new technology (DSC, Organic cell)
* Traceability to production line
- Research for Reliability evaluation method
* Long-term outdoor exposure test
* Correlation between Lab test and outdoor test
* Acceleration test
TÜV Rheinland Japan Photovoltaic Department
2009-10-15
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TÜV Rheinland - Precisely Right
We Advise
Develop
Facilitate
Test
Certify
Thank you for your attention
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2009-10-15
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