标准测试条件下双面组件背部光谱辐照度的建模方法及其在额定功率方面的-高祺-TÜV莱茵（上海）有限公司

11th PVPMC, 4th – 5th Dec. 2018, Weihai, China Modeling Method for Rear-face Spectral Irradiance at Standard Test Condition and Its Application to Power Rating of Bifacial PV Module 标准测试条件下背面光谱辐照度的建模方法及其在双面光伏组件功率标定中的应用 Q. Gao1, C. Monokroussos1, X. Y. Zhang1, E. Lee1, Y.H. Wang1, C. Zou1, L. Rimmelspacher2, J. Bonilla Castro2, M. Schweiger2 and W. Herrmann2 1 TÜV Rheinland (Shanghai) Co., Ltd., No.177, Lane 777, West Guangzhong, 200072, Shanghai, P.R. China 2 TÜV Rheinland Energy GmbH, Am Grauen Stein, 51105, Cologne, Germany Outline 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China2  Introduction and Motivation 研究背景  Standard and Literature Review 双面光伏器件测试标准回顾  Modelling Approach and Simulation Results 双面组件光谱辐照度建模方法与模拟结果  Comparison with Outdoor Measurements 户外测试结果验证  Definition of Bifacial Standard Test Conditions (BSTC) 双面标准测试条件  Application to Power Rating BSTC在双面光伏组件标定中的应用  Summary and Conclusions 总结 Introduction and Motivation 研究背景 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China3  Sales price of PV modules is based on STC measurements 光伏组件在标准测试条件下的标定功率直接影响其定价基准  Bifacial modules have higher performance (PR100%) than monofacial, due to the contribution of rear face irradiance 由于背面辐照度增益，双面光伏组件性能比往往大于 100%  PV-modules with unclear rating conditions were seen in the market 在光伏市场中，双面光伏组件的标定条件依然不明确 Introduction and Motivation 研究背景 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China4  Sales price of PV modules is based on STC measurements 光伏组件在标准测试条件下的标定功率直接影响其定价基准  Bifacial modules have higher performance (PR100%) than monofacial, due to the contribution of rear face irradiance 由于背面辐照度增益，双面光伏组件性能比往往大于 100%  PV-modules with unclear rating conditions were seen in the market 在光伏市场中，双面光伏组件的标定条件依然不明确 Do we need a supplementary rating test condition for bifacial module performance? 对于双面光伏组件性能测试，我们是否需要一个补充测试条件？ ? Extension of STC needed? STC的延伸条件是否必要？ 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China5  Fielded bifacial PV modules Field parameters greatly affected by rear side irradiance, GR 双面光伏组件的发电能力极大地受到背面辐照度的影响 Commercial bifacial module types vary in terms of bifaciality (60-90%) 不同种类双面组件的双面率亦有所不同  Consumer view: Additional power labelling to differentiate products is necessary 从用户的角度看，额外的功率标签非常必要  Reference GR value for BSTC? BSTC中背面参考辐照度应为？  Ray-tracing simulations: 光线追踪法测试结果？ Rear side irradiance lies in the range 120-135 W/m² for parameters given in the table using Radiance software 如右表中条件，组件背面辐照度在 120-135 W/m² 。 Field parameter Bifacial reference conditions Albedo 0.21 (light soil) Height above ground 1 m Inclination angle 37° Front side irradiance 1000 W/m2 Reference: C. Deline et al., Assessment of Bifacial Photovoltaic Module Power Rating Methodologies - Inside and Out, IEEE Journal of Photovoltaics Vol. 7, No. 2 (2017) 04.12.2018 IEC 60904-1-2: Test Method for IV Measurement of Bifacial PV-Modules 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China6 𝐺𝐸𝑖 = 1000 W/m² + 𝜑 ∗𝐺𝑅𝑖 𝝋= 𝑀𝑖𝑛 (𝝋𝑰𝒔𝒄, 𝝋𝑷𝒎𝒂𝒙) G=1 kW/m2 G=1 kW/m2 IEC 60904-1-2 CD 𝐺𝑅𝟏 = 100 W/m² 𝐺𝑅𝟐 = 200 W/m² 𝐺𝑅𝟑 = xxx W/m² 𝑮𝑬𝒊 04.12.2018 IEC 60904-1-2: 双面光伏组件 I-V曲线测试方法 Modelling Approach 建模方法 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China7 Esλ = cosθ · Ebnλ + Rd · Edλ + ρgλ · Rr · Eλ Direct Beam Component Diffuse Beam Component Albedo Component Global Tilted Irradiance Reference: C. Guyemard et al., “SMARTS2: A simple model of the atmospheric radiative transfer of Sunshine: Algorithms and performance assessment”, FSEC-PF-270-95 (1995) 04.12.2018 Field parameter Bifacial reference condition Beam & Circumsolar Irradiance - As defined in IEC 60904-3 Diffuse Irradiance - As defined in IEC 60904-3 - Isotropic diffuse 各向同性散射 Ground Albedo - Lambertian diffuse reflector 朗伯特散射面 - Light sandy soil with spectral albedo as given in SMARTS v. 2.9.5 SMARTS中细砂土光谱反射率 Air Mass 1.5 Inclination angle 37° Front side irradiance 1000 W/m2 Shading No near shading 无周边遮挡 PV-array design Single row, 10 modules 单排阵列，每排组件数量大于 10 倾斜面全局 辐照度 直射部分 散射部分 反射部分 Modelling Approach 建模方法 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China8 Esλ = Rd · Edλ + ρgλ · Rbnλ · Ebnλ + ρgλ · Rd · Edλ Diffuse Beam Component Albedo Direct Beam Component Rear Face Tilted Irradiance Reference: C. Guyemard et al., “SMARTS2: A simple model of the atmospheric radiative transfer of Sunshine: Algorithms and performance assessment”, FSEC-PF-270-95 (1995) 04.12.2018 Albedo Diffuse Beam Component Field parameter Bifacial reference condition Beam & Circumsolar Irradiance - As defined in IEC 60904-3 Diffuse Irradiance - As defined in IEC 60904-3 - Isotropic diffuse 各向同性散射 Ground Albedo - Lambertian diffuse reflector 朗伯特散射面 - Light sandy soil with spectral albedo as given in SMARTS v. 2.9.5 SMARTS中细砂土光谱反射率 Air Mass 1.5 Inclination angle 37° Front side irradiance 1000 W/m2 Shading No near shading 无周边遮挡 PV-array design Single row, 10 modules 单排阵列，每排组件数量大于 10 Height above ground 1 m Module Transmittance - Spectral Transmittance of Glass/EVA/Glass, Glass/POE/Glass structures 不同封装结构透射率 - Solar Cell Transmittance 太阳电池透射率 - Angular response of bifacial modules 角度响应背面辐照度 直射光反射散射部分 散射光反射 Modelling Approach 建模方法 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China9 Field parameter Bifacial reference condition Beam & Circumsolar Irradiance - As defined in IEC 60904-3 Diffuse Irradiance - As defined in IEC 60904-3 - Isotropic diffuse 各向同性散射 Ground Albedo - Lambertian diffuse reflector 朗伯特散射面 - Light sandy soil with spectral albedo as given in SMARTS v. 2.9.5 SMARTS中细砂土光谱反射率 Air Mass 1.5 Inclination angle 37° Front side irradiance 1000 W/m2 Shading No near shading 无周边遮挡 PV-array design Single row, 10 modules 单排阵列，每排组件数量大于 10 Height above ground 1 m Module Transmittance - Spectral Transmittance of Glass/EVA/Glass, Glass/POE/Glass structures 不同封装结构透射率 - Solar Cell Transmittance 太阳电池透射率 - Angular response of bifacial modules 角度响应 Esλ = Rd · Edλ + ρgλ · Rbnλ · Ebnλ + ρgλ · Rd · Edλ Reference: C. Guyemard et al., “SMARTS2: A simple model of the atmospheric radiative transfer of Sunshine: Algorithms and performance assessment”, FSEC-PF-270-95 (1995) 04.12.2018 Esλ, Ebnλ, Edλ, Eλ : Spectral irradiance components Rbnλ, Rd, Rr : Angular and field of view components ρgλ: Spectral albedo AM1.5G Spectral Irradiance at Rear Face 对应于 AM1.5G的背面光谱 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China10 • Accounting for the methodology used in SMARTS2, a physics-based model was created, which can compute radiation distributions on tilted surfaces and their spectrum. 该物理模型参考 SMARTS2的光谱计算方法，可以用于计算倾斜面的光谱辐照度。 • It is shown that rear face irradiance distribution for PV-modules deployed in a single row at 1 m above ground at conditions as defined in AM1.5G is strongly non-uniform. Landscape mounting configuration is beneficial for bifacial modules. 1m安装高度的光伏组件背面光谱辐照度在组件上分布不均，横向安装方式更为有益。 • The spectral distribution of the irradiance at rear face is red-shifted due to spectral albedo effects. 相比于正面光谱，背面光谱有一定红移，所以功率标定中 正反面 失配系数不同。 04.12.2018 Irradiance Distribution at Rear Face, GR Elev ation [m ] 0 4 0 0 8 0 0 1 2 0 0 1 6 0 0 2 0 0 0 2 4 0 0 2 8 0 0 3 2 0 0 3 6 0 0 4 0 0 0 0 0 . 2 0 . 4 0 . 6 0 . 8 1 W a v e l e n g t h [ n m ] N o r m a li se d S p e c tr a l Ir r a d ia n ce [ a u ] A M 1 . 5 G a t f r o n t f a ce A M 1 . 5 G a t r e a r f a ce GR [W/m2] Ground Irradiance Non-Uniformity of Irradiance and Average Photon Energy 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China11 04.12.2018 P V - m o d u le w i d t h [ m ] P V - m o d u l e l e n g t h [ m ] I r r a d i a n c e a t R e a r F a c e 0 0 . 2 0 . 4 0 . 6 0 . 8 0 0 . 2 0 . 4 0 . 6 0 . 8 1 1 . 2 1 . 4 1 . 6 1 . 8 120 130 140 150 160 170 G R [ W / m 2 ] P V - m o d u le w i d t h [ m ] P V - m o d u l e l e n g t h [ m ] A v e r a g e P h o t o n E n e r g y a t R e a r F a c e 0 0 . 2 0 . 4 0 . 6 0 . 8 0 0 . 2 0 . 4 0 . 6 0 . 8 1 1 . 2 1 . 4 1 . 6 1 . 8 1 . 6 4 5 1 . 6 5 1 . 6 5 5 1 . 6 6 1 . 6 6 5 1 . 6 7 A P E [ e V ] Example: 2m x 1m sized, frameless PV-module deployed in portrait configuration at 1 m above ground at conditions as defined in AM1.5G. 背面辐照度与平均光子能量不均匀度分布 2m x 1m无边框双面组件在安装高度，正面光谱辐照度 AM1.5G时的背面辐照度与平均光子能量分布。 • The rear face irradiance, GR lies in the range of 110- 180 W/m2. Top-row: 110-145W/m2 Bottom-row: 145-180W/m2 背面辐照度在 110-180 W/m2范围内： 顶部阵列 110-145W/m2 底部阵列 145-180W/m • The average photon energy (300-1200nm) varies within 1.64-1.68eV (1.80eV of front face). 在 300-1200nm范围内的平均光子能 量为 1.64-1.68eV。 IEC 60904-1-2: Test Method for IV Measurement of Bifacial PV-Modules 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China12 𝐺𝐸𝑖 = 1000 W/m² + 𝜑 ∗𝐺𝑅𝑖 𝝋= 𝑀𝑖𝑛 (𝝋𝑰𝒔𝒄, 𝝋𝑷𝒎𝒂𝒙) G=1 kW/m2 G=1 kW/m2 𝑮𝑬𝒊 04.12.2018 • Front irradiance: 1000 W/m² • Rear irradiance: 135 W/m² • Equivalent irradiance: 1000 + φ·135 W/m² • Module temperature: 25°C • Spectral irradiance: AM1.5G [1] 2PfG 2645/11.17: Supplementary Power Rating of Bifacial Photovoltaic (PV) Modules IEC 60904-1-2 CD 𝐺𝑅𝟏 = 100 W/m² 𝐺𝑅𝟐 = 200 W/m² 𝐺𝑅𝟑 = xxx W/m² 2PfG 2645/11.17 𝐺𝑅𝟏 = 100 W/m² 𝐺𝑅𝟐 = 200 W/m² 𝐺𝑅𝟑 = 135 W/m² IEC 60904-1-2: 双面光伏组件 I-V曲线测试方法 Comparison with Outdoor Measurements: Rear Face Horizontal Irradiance 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China13 Measurement Conditions Site: Cologne Date: 15/08/2018 Time: 13:00, Solar Noon Air Mass: AM1.2 Sky Condition: Clear Skies Height: 1.5m Model Parameters Air Mass: AM1.2 GHI: SMARTS (2.9.5) DNI: SMARTS (2.9.5) Albedo: Light Sandy Soil Height: 1.5m 水平面背面光谱辐照度模拟结果与户外实测值对比 Comparison with Outdoor Measurements: Rear Face Horizontal Irradiance 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China14 The Spectral Albedo was measured with a spectroradiometer and two pyranometers (Rear Face HIλ/GHIλ). 光谱反射率由一台光谱仪与两台辐照计测量。 水平面背面光谱辐照度模拟结果与户外实测值对比 Comparison with Outdoor Measurements: Rear Face Horizontal Irradiance 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China15 水平面背面光谱辐照度模拟结果与户外实测值对比 Comparison with Outdoor Measurements: Rear Face Horizontal Irradiance 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China16 水平面背面光谱辐照度模拟结果与户外实测值对比 Comparison with Outdoor Measurements: Rear Face Horizontal Irradiance 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China17 水平面背面光谱辐照度模拟结果与户外实测值对比 Comparison with Outdoor Measurements: Rear Face Horizontal Irradiance 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China18 水平面背面光谱辐照度模拟结果与户外实测值对比 Significance of Rear Face Spectral Irradiance for Bifacial Module Rating 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China19 Sample Type Qty DUTs:(encapsulated) SRfront + SRrear Bifaciality, φ Bifacial c-Si PV (PERC, HJT, PERT) 20 Reference Cell SR c-Si 8 Solar Simulator Spectra A 14B 3 背面光谱分布对双面光伏组件标定的影响 SMM1: SRfront and AM1.5G SMM2: SRrear and AM1.5G SMM3: SRrear and AM1.5R SMM1+2: 1000 𝑆𝑀𝑀1 + 𝜑 135 𝑆𝑀𝑀2 1000 +135·𝜑 SMM1+3: 1000 𝑆𝑀𝑀1 + 𝜑 135 𝑆𝑀𝑀3 1000 +135·𝜑 Significance of Rear Face Spectral Irradiance for Bifacial Module Rating 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China20 • The rear face spectral mismatch strongly depends on the reference spectrum choice (AM1.5G or AM1.5R) 背面光谱失配系数依赖于参考光谱选择。 • The weighted spectral mismatch is not significantly affected by the rear face spectral distribution choice (AM1.5G or AM1.5R) 加权光谱失配系数受参考光谱影响不大。  Practically AM1.5G can be used for both sides without significant error AM1.5G可以应用于实际双面光谱失配系数的计算 。 背面光谱分布对双面光伏组件标定的影响 95.00% 96.00% 97.00% 98.00% 99.00% 100.00% 101.00% 102.00% 103.00% 104.00% N-type #1 N-type #2 N-type #3 P-type #1 HJT #1 φ Vo c Sample size: 10-20 modules per type Bifaciality Coefficients Dispersion seen in Production 21 50.00% 55.00% 60.00% 65.00% 70.00% 75.00% 80.00% 85.00% 90.00% 95.00% 100.00% N-type #1 N-type #2 N-type #3 P-type #1 HJT #1 φ Pm ax Sample size: 10-20 modules per type 50.00% 55.00% 60.00% 65.00% 70.00% 75.00% 80.00% 85.00% 90.00% 95.00% 100.00% N-type #1 N-type #2 N-type #3 P-type #1 HJT #1 φ Isc Sample size: 10-20 modules per type • The variation of bifaciality coefficients, φ, was evaluated by measuring a series of modules in production (10-20 modules per type). • Bifaciality depends strongly on technology. Coefficients may vary from 60% to 90%. • Bifaciality coefficients may vary from ±2.0% to ±5.0% (k=2) in production for as-produced modules of the same family.  BSTC tolerance shall account this variation to comply with supplementary label verification in accordance with gate #1 requirements. 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China 双面率在实际产线中的分布 Verification of BSTC Values on the Label (Gate #1) 22 • Stabilized 𝑃𝑚𝑎𝑥 of each sample with consideration of plus- uncertainty ≥ Nominal Power with consideration of minus- tolerance𝑃𝑚𝑎𝑥 (BSTC) • Average of stabilized 𝑃𝑚𝑎𝑥 values of all samples with consideration of plus-uncertainty ≥ Nominal Power𝑃𝑚𝑎𝑥 (BSTC) • Stabilized 𝑉𝑜𝑐 with consideration of plus-uncertainty ≤ nominal value on type label with consideration of plus- tolerance 𝑉𝑜𝑐 (BSTC) • Stabilized 𝐼𝑠𝑐 with consideration of plus-uncertainty ≤ nominal value on type label with consideration of plus- tolerance 𝐼𝑠𝑐 (BSTC) • Stabilized 𝑃𝑚𝑎𝑥 with consideration of minus-uncertainty ≤ Nominal Power with consideration of plus-tolerance 𝑃𝑚𝑎𝑥 (BSTC) for minimum power class 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China 标签中 BSTC相关数值的验证准则 Conclusions 结论 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China23  Power labelling of bifacial PV modules is an urgent matter. Sufficient knowledge is available to define bifacial reference conditions. 双面光伏组件的功率标签十分必要，现有理论已足够定义双面测试标准状况  Bifacial Standard Test Condition (BSTC) has been proposed based on IEC 60904-1-2 CDTS and IEC 60904-3, which intends to provide supplementary information on the label: 双面标准测试条件（ BSTC）的制定基于 IEC 60904-1-2 CDTS和 IEC 60904-3，可用于在标签上提供补充信息： Bifacial Standard Test Conditions (BSTC) : • Front irradiance: 1000 W/m² • Rear irradiance: 135 W/m² • Equivalent irradiance: 1000 + φ·135 W/m² • Spectral irradiance: AM1.5G • Module temperature: 25°C  BSTC is a simple indicator, which is unsuitable for EY predictions. BSTC只是一个测试条件，不能应用于发电量预测。  Energy rating standard according to IEC 61853 should be extended for bifacial applications. 基于 IEC 61853的功率标定标准可被拓展到双面光伏组件中。 Acknowledgements 04.12.2018 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China24  Mr. Yabin Li, Mr. Fan Wang and Dr. Jason Nee from Yingli Solar  Mr. Thomas Guo and Dr. Jin Hao from Jinko Solar  Dr. Thomas R. Betts from Loughborough University, UK for the helpful discussions and data contribution. 04.12.201825 Acknowledgements 11th PVPMC, 4th – 5th Dec. 2018, Weihai, China Participators Thank you for your attention !