应用光线追踪方法建模双面电站系统范例与验证-薄中南 Jefferson Bor-Fraunhofer ISE-solarbe文库

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© Fraunhofer ISE ©Fraunhofer ISE / Photo Guido Kirsch 薄中南 Jefferson Bor 弗朗霍夫太阳能研究所 ISE Special thanks to Dr. C. Reise, J. Kang, Fraunhofer ISE M.Chiodetti, EDF Fraunhofer Institute for Solar Energy Systems ISE PVPMC, Weihai, 05.12.2018 Ray tracing methodology for Bifacial System modeling Exemplar and Validation 应用光线追踪方法建模双面电站系统范例与验证 photo provided by NEOEN © Fraunhofer ISE 2 议程 AGENDA 1. 双面建模的挑战 2. 光线跟踪法如何运作 3. 实际应用范例 4. 模型验证 5. 结论与展望 1. Main Challenges for Bifacial Simulation 2. How does Ray Tracing Method Works 3. Project and Test Exemplars 4. Validation of the Model Performance 5. Conclusion and Perspectives Expected development of monofacial and bifacial modules share of the world market Source ITRPV report 20171 © Fraunhofer ISE 3 双面的效率与发电 Bifacial Efficiency and Power 一个直观的想法 A Straight Forward Thinking Yield Gfront * efffront Grear * effrear Gfront * efffront Grear * efffront * BF STC value optical gain bifaciality factor 18 22 5 50 75 95 these factors determine bifacial gain module property system property module property laboratory software laboratory © Fraunhofer ISE 4 影响双面增益的因子 Factors affecting bifacial gain  支架几何 the mounting geometry  高度 height  倾角 module tilt  间距 row-to-row distances GCR  地面反射率与不均匀度the ground albedo and its homogeneity  支架结构 the mounting structure  组件双面特性 Bifacial characteristics of module  许多因素并不影响单面系统的模拟 Mono-facial system simulation is not affected by most of these factors © Fraunhofer ISE 5 双面模拟的挑战 Main challenges for bifacial simulation  背面辐照不均匀 Non-uniformly distributed radiation on the rear side  周遭物体都有不同的反射或散射特性 All surrounding objects have different patterns of reflection and scattering  Other adaptation compared to mono-facial model  Electrical modelling for the two-side irradiance  Modified thermal behaviour Winter Summer Measured irradiance from 3 pyranometers mounted on the rear side of a bifacial system © Fraunhofer ISE 6 双面系统的建模 Modeling of bifacial system  主要的两种模型 Two dominating method for modeling  View factor method  光线跟踪法 Ray tracing method JCT, ECN, CEA INES, ISC KONSTANZ, REC, SERIS, Sandia, NREL, University of Iowa, RTWH,, Enel, Pvsyst, Polysun, University of Nevada, Fraunhofer CSP, ZHAW, Univertsity of Stuttgart, KAUST [1] [1] Source J. Libal et al., bifi PV workshop October 26, 2017 Fraunhofer ISE, EDF [1] , SERIES Singapore © Fraunhofer ISE 7 The View Factors Method  View Factor fraction of radiation from s1, s2 or more that hits the m surface 优点 Pros  较容易应用 Can be easily implemented  运算快速 Low computing time 缺点 Cons  复杂的形状较难考虑 Complex geometries are difficult to be considered  支架结构与外物遮蔽等细节较难整合 Mounting structure and shading objects are hard to be integrated 使用者多, 结果不错 Mainly applied, decent result EdF RD 2014 © Fraunhofer ISE 8 光线跟踪法 The Ray Tracing Method  反向光线跟踪计算 Backward ray tracing calculation © Fraunhofer ISE 9 光线跟踪法 The Ray Tracing Method  光线发射后-每束光开始经历 Light begins to travel back – each beam will 1. 碰到障碍物 Hit obstacles 根据周遭环境 depending on surrounding 2. 镜面反射或散射 Specular reflect or scatter 根据材料表面depending on material surface 3. 最终到达天空半球顶 Hit the sky hemisphere 2D示意图为了简单表现光线跟踪法概念图中简化光束数量 2D illustration The amount of beams is reduced to better conceptualized the ray tracing method © Fraunhofer ISE 10 光线跟踪法 The Ray Tracing Method  光线发射后-每束光开始经历 Light begins to travel back – each beam will 1. 碰到障碍物 Hit obstacles 根据周遭环境 depending on surrounding 2. 镜面反射或散射 Specular reflect or scatter 根据材料表面depending on material surface 3. 最终到达天空半球顶 Hit the sky hemisphere 2D示意图为了简单表现光线跟踪法概念图中简化光束数量 2D illustration The amount of beams is reduced to better conceptualized the ray tracing method © Fraunhofer ISE 11 光线跟踪法 The Ray Tracing Method  光线发射后-每束光开始经历 Light begins to travel back – each beam will 1. 碰到障碍物 Hit obstacles 根据周遭环境 depending on surrounding 2. 镜面反射或散射 Specular reflect or scatter 根据材料表面depending on material surface 3. 最终到达天空半球顶 Hit the sky hemisphere 2D示意图为了简单表现光线跟踪法概念图中简化光束数量 2D illustration The amount of beams is reduced to better conceptualized the ray tracing method © Fraunhofer ISE 12 Model and Sky 9 O‘Clock at 21. September in Freiburg 按角度解析的辐照值 Angle-resolved Irradiance Value 辐照密度场 Radiation Density Fields © Fraunhofer ISE 13 正面 Field of view, front side 按角度解析的辐照值 Angle-resolved Irradiance Value 辐照密度场 Radiation Density Fields © Fraunhofer ISE 14 正面 Field of view, front side 按角度解析的辐照值 Angle-resolved Irradiance Value 辐照密度场 Radiation Density Fields © Fraunhofer ISE 15 背面 Field of view, rear side 按角度解析的辐照值 Angle-resolved Irradiance Value 辐照密度场 Radiation Density Fields © Fraunhofer ISE 16 光线跟踪法 The Ray Tracing Method  想象成背面每一观察点有一个假想的传感器 Just image Virtual Sensor on each defined point  求全部点平均 Average of all points 每个点会射出1024条光线每一次的反射后，每一条会再变成至多1024 条举例 3次反射后我们总共会有10 1 2 条光束 1024 Beams sent out from each point After each reflection, one beam will become 1024 beams Ex after 3 reflections, we will get max. 10 1 2 beams © Fraunhofer ISE 17 光线跟踪法 The Ray Tracing Method 优点 Pros  贴近真实的背面辐射 Realistic rear side irradiance  3D 的不均匀分布 Considering inhomogeneity in 3D  可以重建细节结构, 空间分布, 物体 Possible to build up all configurations structure, spacing, objects  可以整合CAD软件 Possible to feed-in with CAD software 缺点 Cons  较不易整合进现有模型 Less easy to implement  计算较为耗时 Computing time consuming © Fraunhofer ISE 18 光线跟踪法应用实例 Appliance Exemplar with ISE Ray Tracing Model 85MW 约旦 85MW, Jordan  85MW, Jordan  2302 kWh/m² avg. 2008-2017  DNI 1738 kWh/m²  DHI 564 kWh/m²  Bright sand – Abeldo 30  Bifacial module, 76 bifaciality factor  Horizontal single axis tracker  Row distance 13m GCR 31  Height 2.8 meter Dark rocks and soil will be removed to expose the white sand Source Soltec, https//soltec.com/soltec-unveils-the-sf7-tracker-that-achieves-higher-yield-and-lower-cost/ © Fraunhofer ISE 19 光线跟踪法应用实例 Appliance Exemplar with ISE Ray Tracing Model 85MW 约旦 85MW, Jordan © Fraunhofer ISE 20 6 am 12 pm 15 pm 光线跟踪法应用实例 Appliance Exemplar with ISE Ray Tracing Model 日变化, 85MW 约旦 Daily Change 85MW, Jordan © Fraunhofer ISE 21 6 am 12 pm 15 pm 不同阴影密度不同反射辐照比例 Different density of shadow means different amount of reflected irradiance 光线跟踪法应用实例 Appliance Exemplar with ISE Ray Tracing Model 日变化, 85MW 约旦 Daily Change 85MW, Jordan © Fraunhofer ISE 22 越靠近边缘越亮散射光线较多 Closed to the edge is brighter means More diffuse light incoming 光线跟踪法应用实例 Appliance Exemplar with ISE Ray Tracing Model 不均匀度85MW 约旦 Inhomogeneity 85MW, Jordan © Fraunhofer ISE 23  Specific Yield 2,703 kWh/kWp  光线增益 BGopt Grear / Gfront 10.9  组件增益 BGmod Grear * bf / Gfront 8.3  系统增益 BGsys Erear / Efront Ebifi – Emono / Emono 7.1 光线跟踪法应用实例 Appliance Exemplar with ISE Ray Tracing Model 结果85MW 约旦 Result 85MW, Jordan © Fraunhofer ISE 24  Specific Yield 2,703 kWh/kWp  光线增益 BGopt Grear / Gfront 10.9  组件增益 BGmod Grear * bf / Gfront 8.3  系统增益 BGsys Erear / Efront Ebifi – Emono / Emono 7.1 组件特性 Module characteristic 系统几何设计 System geometry 电气设计 Electrical design 光线跟踪法应用实例 Appliance Exemplar with ISE Ray Tracing Model 结果85MW 约旦 Result 85MW, Jordan © Fraunhofer ISE 27 模型验证 Model Validation  与法国电力共同合作项目 Joint project with EDF  Results revealed on Sep. 26 th 2018 at EU PVSEC, Belgium  法电与ISE 的不同光伏系统 PV Installations from EDF and ISE Source M. Chiodetti et al., EU PVSEC, Belgium, Sep. 26th 2018 © Fraunhofer ISE 28  不同水平验证 On different level  辐照 Irradiance  发电参数 Electrical value  监测数据包含 Monitoring at  水平与反射辐照 GHI front and Albedo horizontal  环境与组件温度 Ambient and module temperature  直流测电流电压功率Current, voltage and power on DC side  数据筛选 Data Filtering Source M. Chiodetti et al., EU PVSEC, Belgium, Sep. 26th 2018 模型验证 Model Validation © Fraunhofer ISE 29 模型验证,法国7个月 Model Validation, France 7 Months Irradiance measurement vs simulation Winter Summer Source M. Chiodetti et al., EU PVSEC, Belgium, Sep. 26th 2018 © Fraunhofer ISE 30 模型验证,法国7个月 Model Validation, France 7 Months Power measurement vs simulation  n-PERT modules  fixed-tilt 30° with 50 GCR  Albedo 30 Source M. Chiodetti et al., EU PVSEC, Belgium, Sep. 26th 2018 © Fraunhofer ISE 31 模型验证,加州6个月 Model Validation, California 6 Months Power measurement vs simulation  p-PERC modules  Single axis tracker, with 35 GCR  Albedo 32 Source M. Chiodetti et al., EU PVSEC, Belgium, Sep. 26th 2018 © Fraunhofer ISE 32 结论 Summary  双面系统会有更高的发电量  发电模型可以有贴近单面模型的准确率  均方根值低于7  平均偏差 ±4  在解读双面增益时很重要的一定要了解数据背后的边界条件  Bifacial PV systems may achieve high performance  Simulation may reach similar accuracy as with monofacial systems  Root Mean Square Errors below 7  Mean Bias Errors ±4  When interpreting the Bifacial gain, always pay attention to the boundary condition © Fraunhofer ISE 33 结论 Summary 更进一步研究 Further Investigation  对比view factor 模型 Comparison with models based on view factor theory  验证更多电站数据 Validation with more real system performance data  模型加强 Model improvement  反照率的变动 Albedo variability  双面的电气模型 Bifacial electrical model  热建模 Thermal model  长期双面组件衰减 Long-term bifacial module degradation © Fraunhofer ISE 34 谢谢您的参与 Thank you for your attention Fraunhofer Institute for Solar Energy Systems ISE Jefferson Bor www.ise.fraunhofer.de jefferson.borise.fraunhofer.de