1.
M Schlemminger; D Bredemeier; A Mahner; R Niepelt; M H Breitner; R Brendel
In: Progress in Photovoltaics: Research and Applications, Bd. 32, Nr. 12, S. 912-929, 2024.
@article{Schlemminger2024d,
title = {Rooftop PV Potential Determined by Backward Ray Tracing: A Case Study for the German Regions of Berlin, Cologne, and Hanover},
author = {M Schlemminger and D Bredemeier and A Mahner and R Niepelt and M H Breitner and R Brendel},
doi = {10.1002/pip.3844},
year = {2024},
date = {2024-12-01},
urldate = {2024-09-18},
journal = {Progress in Photovoltaics: Research and Applications},
volume = {32},
number = {12},
pages = {912-929},
abstract = {Photovoltaics (PV) on building rooftops is a major contributor to the decarbonization of energy systems. We simulate the PV energy yield potential for 2.5 million individual roofs in three German regions. We cumulate the results for each single roof to calculate the cost-potential curves for the three cities Berlin, Cologne, and Hanover. These curves give the amount of electricity that can be generated at less than a given cost per kWh. We find that these curves have the shape of a hockey stick. Neglecting the dependence of PV investment on building size and thus on the system sizes causes largely different cost-potential curves that differ by 11%–18% for flat roofs due to their heterogeneous building size distribution. The cost-potential curves of the three cities are very similar when appropriately normalized, for example, by the local solar irradiation and the settlement area of the city, despite substantial variations in population density. This allows for an extrapolation of our results. For Germany, we reveal an upper limit for the total electricity generation from rooftop PV of 762 TWh/a with cost as low as 6.9 ct/kWh without accounting for area losses due to chimneys, air conditioning systems, and so forth. We estimate the actual potential to be at least half of that figure.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Photovoltaics (PV) on building rooftops is a major contributor to the decarbonization of energy systems. We simulate the PV energy yield potential for 2.5 million individual roofs in three German regions. We cumulate the results for each single roof to calculate the cost-potential curves for the three cities Berlin, Cologne, and Hanover. These curves give the amount of electricity that can be generated at less than a given cost per kWh. We find that these curves have the shape of a hockey stick. Neglecting the dependence of PV investment on building size and thus on the system sizes causes largely different cost-potential curves that differ by 11%–18% for flat roofs due to their heterogeneous building size distribution. The cost-potential curves of the three cities are very similar when appropriately normalized, for example, by the local solar irradiation and the settlement area of the city, despite substantial variations in population density. This allows for an extrapolation of our results. For Germany, we reveal an upper limit for the total electricity generation from rooftop PV of 762 TWh/a with cost as low as 6.9 ct/kWh without accounting for area losses due to chimneys, air conditioning systems, and so forth. We estimate the actual potential to be at least half of that figure.
2.
D Bredemeier; C Schinke; R Niepelt; R Brendel
In: Progress in Photovoltaics: Research and Applications, Bd. 32, Ausg. 4, S. 232-243, 2024.
@article{Bredemeier2023,
title = {Large-scale spatiotemporal calculation of photovoltaic capacity factors using ray tracing: A case study in urban environments},
author = {D Bredemeier and C Schinke and R Niepelt and R Brendel},
doi = {10.1002/pip.3756},
year = {2024},
date = {2024-04-01},
urldate = {2023-11-29},
journal = {Progress in Photovoltaics: Research and Applications},
volume = {32},
issue = {4},
pages = {232-243},
abstract = {Photovoltaics (PVs) on building facades, either building-integrated or building-attached, offer a large energy yield potential especially in densely populated urban areas. Targeting this potential requires the availability of planning tools such as insolation forecasts. However, calculating the PV potential of facade surfaces in an urban environment is challenging. Complex time-dependent shadowing and light reflections must be considered. In this contribution, we present fast ray tracing calculations for insolation forecasts in large urban environments using clustering of Sun positions into typical days. We use our approach to determine time resolved PV capacity factors for rooftops and facades in a wide variety of environments, which is particularly useful for energy system analyses. The advantage of our approach is that the determined capacity factors for one geographic location can be easily extended to larger geographic regions. In this contribution, we perform calculations in three exemplary environments and extend the results globally. Especially for facade surfaces, we find that there is a pronounced intra-day and also seasonal distribution of PV potentials that strongly depends on the degree of latitude. The consideration of light reflections in our ray tracing approach causes an increase in calculated full load hours for facade surfaces between 10% and 25% for most geographical locations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Photovoltaics (PVs) on building facades, either building-integrated or building-attached, offer a large energy yield potential especially in densely populated urban areas. Targeting this potential requires the availability of planning tools such as insolation forecasts. However, calculating the PV potential of facade surfaces in an urban environment is challenging. Complex time-dependent shadowing and light reflections must be considered. In this contribution, we present fast ray tracing calculations for insolation forecasts in large urban environments using clustering of Sun positions into typical days. We use our approach to determine time resolved PV capacity factors for rooftops and facades in a wide variety of environments, which is particularly useful for energy system analyses. The advantage of our approach is that the determined capacity factors for one geographic location can be easily extended to larger geographic regions. In this contribution, we perform calculations in three exemplary environments and extend the results globally. Especially for facade surfaces, we find that there is a pronounced intra-day and also seasonal distribution of PV potentials that strongly depends on the degree of latitude. The consideration of light reflections in our ray tracing approach causes an increase in calculated full load hours for facade surfaces between 10% and 25% for most geographical locations.
3.
J Schumann; B Schiebler; F Giovannetti
Performance Evaluation of an Evacuated Tube Collector with a Low-Cost Diffuse Reflector Artikel
In: Energies, Bd. 14, Nr. 24, 2021, ISSN: 1996-1073.
@article{Schumann2021,
title = {Performance Evaluation of an Evacuated Tube Collector with a Low-Cost Diffuse Reflector},
author = {J Schumann and B Schiebler and F Giovannetti},
doi = {10.3390/en14248209},
issn = {1996-1073},
year = {2021},
date = {2021-12-01},
journal = {Energies},
volume = {14},
number = {24},
abstract = {In order to increase the overall solar energy gain of evacuated tube collectors, rear-side reflectors are used. In this way, the otherwise unused incident radiation between the tubes can be reflected back to the absorber, and the performance of the collector can be improved. In this paper, the use of a low-cost, diffusely reflecting, trapezoidal roof covering made from a galvanized metal sheet is investigated and compared to a high-quality, specularly reflecting plane reflector made of aluminum. For this purpose, ray-tracing analysis and TRNSYS simulations were carried out. In the ray-tracing analysis, the experimentally determined zero-loss collector efficiency η0 as well as the incident angle modifiers for each reflector can be reproduced with an error lower than 7.5%. Thermal system simulations show that the performance of both reflectors is comparable. The use of the low-cost reflector leads to an increase in annual collector output of around 30% compared to an increase with the specular reflector of around 33%. Considering a typical domestic hot water system, both reflectors enable an increase in the solar annual yield of approx. 11%.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In order to increase the overall solar energy gain of evacuated tube collectors, rear-side reflectors are used. In this way, the otherwise unused incident radiation between the tubes can be reflected back to the absorber, and the performance of the collector can be improved. In this paper, the use of a low-cost, diffusely reflecting, trapezoidal roof covering made from a galvanized metal sheet is investigated and compared to a high-quality, specularly reflecting plane reflector made of aluminum. For this purpose, ray-tracing analysis and TRNSYS simulations were carried out. In the ray-tracing analysis, the experimentally determined zero-loss collector efficiency η0 as well as the incident angle modifiers for each reflector can be reproduced with an error lower than 7.5%. Thermal system simulations show that the performance of both reflectors is comparable. The use of the low-cost reflector leads to an increase in annual collector output of around 30% compared to an increase with the specular reflector of around 33%. Considering a typical domestic hot water system, both reflectors enable an increase in the solar annual yield of approx. 11%.
4.
M R Vogt; R Witteck; T Gewohn; H Schulte-Huxel; C Schinke; M Köntges; K Bothe; R Brendel
Boosting PV Module Efficiency Beyond the Efficiency of Its Solar Cells – A Raytracing Study with Daidalos Now Available to the Scientific Community Proceedings Article
In: WIP, (Hrsg.): Proceedings of the 36th European Photovoltaic Solar Energy Conference and Exhibition, S. 795-800, Marseille, France, 2019, ISBN: 3-936338-60-4.
@inproceedings{Vogt2019c,
title = {Boosting PV Module Efficiency Beyond the Efficiency of Its Solar Cells – A Raytracing Study with Daidalos Now Available to the Scientific Community},
author = {M R Vogt and R Witteck and T Gewohn and H Schulte-Huxel and C Schinke and M Köntges and K Bothe and R Brendel},
editor = {WIP},
doi = {10.4229/EUPVSEC20192019-4BO.11.3},
isbn = {3-936338-60-4},
year = {2019},
date = {2019-10-23},
booktitle = {Proceedings of the 36th European Photovoltaic Solar Energy Conference and Exhibition},
pages = {795-800},
address = {Marseille, France},
abstract = {Today, the PV module energy conversion efficiency is below the efficiency of the cells prior to module integration. Using optical ray tracing simulations, we show how to increase module efficiencies beyond the efficiency of the solar cells. To achieve this we follow two basic principles: First, we minimize optical losses of the module components by minimizing the absorption in the glass and the encapsulation as well as by introducing multilayer glass ARC coatings that reduce the surface reflection. Second, we exploit the internal reflection at the glass-air interface by using light guiding structures in the cell gaps and as cell connects. This improves the light trapping by reducing the cell front side reflection losses. In our specific example presented in this work, the optimization leads to a module efficiency of 20.9%, which is a 0.1%abs above that of the non-encapsulated cells with an efficiency of 20.8%.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Today, the PV module energy conversion efficiency is below the efficiency of the cells prior to module integration. Using optical ray tracing simulations, we show how to increase module efficiencies beyond the efficiency of the solar cells. To achieve this we follow two basic principles: First, we minimize optical losses of the module components by minimizing the absorption in the glass and the encapsulation as well as by introducing multilayer glass ARC coatings that reduce the surface reflection. Second, we exploit the internal reflection at the glass-air interface by using light guiding structures in the cell gaps and as cell connects. This improves the light trapping by reducing the cell front side reflection losses. In our specific example presented in this work, the optimization leads to a module efficiency of 20.9%, which is a 0.1%abs above that of the non-encapsulated cells with an efficiency of 20.8%.
5.
M R Vogt; R Witteck; T Gewohn; H Schulte-Huxel; C Schinke; M Köntges; K Bothe; R Brendel
Boosting PV Module Efficiency Beyond the Efficiency of Its Solar Cells – A Raytracing Study with Daidalos Now Available to the Scientific Community Vortrag
Marseille, France, 10.09.2019, (36th European Photovoltaic Solar Energy Conference and Exhibition).
@misc{Vogt2019b,
title = {Boosting PV Module Efficiency Beyond the Efficiency of Its Solar Cells – A Raytracing Study with Daidalos Now Available to the Scientific Community},
author = {M R Vogt and R Witteck and T Gewohn and H Schulte-Huxel and C Schinke and M Köntges and K Bothe and R Brendel},
year = {2019},
date = {2019-09-10},
address = {Marseille, France},
abstract = {Today, the PV module energy conversion efficiency is below the efficiency of the cells prior to module integration. Using optical ray tracing simulations, we show how to increase module efficiencies beyond the efficiency of the solar cells. To achieve this we follow two basic principles: First, we minimize optical losses of the module components by minimizing the absorption in the glass and the encapsulation as well as by introducing multilayer glass ARC coatings that reduce the surface reflection. Second, we exploit the internal reflection at the glass-air interface by using light guiding structures in the cell gaps and as cell connects. This improves the light trapping by reducing the cell front side reflection losses. In our specific example presented in this work, the optimization leads to a module efficiency of 20.9%, which is a 0.1%abs above that of the non-encapsulated cells with an efficiency of 20.8%.},
note = {36th European Photovoltaic Solar Energy Conference and Exhibition},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Today, the PV module energy conversion efficiency is below the efficiency of the cells prior to module integration. Using optical ray tracing simulations, we show how to increase module efficiencies beyond the efficiency of the solar cells. To achieve this we follow two basic principles: First, we minimize optical losses of the module components by minimizing the absorption in the glass and the encapsulation as well as by introducing multilayer glass ARC coatings that reduce the surface reflection. Second, we exploit the internal reflection at the glass-air interface by using light guiding structures in the cell gaps and as cell connects. This improves the light trapping by reducing the cell front side reflection losses. In our specific example presented in this work, the optimization leads to a module efficiency of 20.9%, which is a 0.1%abs above that of the non-encapsulated cells with an efficiency of 20.8%.
6.
M R Vogt; R Witteck; T Gewohn; H Schulte-Huxel; C Schinke; K Bothe; R Brendel
Ray Tracing of Complete Solar Cell Modules Proceedings Article
In: OSA Advanced Photonics Congress (AP) 2019 (IPR, Networks, NOMA, SPPCom, PVLED), S. PW2C.1, Optical Society of America, Burlingame, California, USA, 2019.
@inproceedings{Vogt2019d,
title = {Ray Tracing of Complete Solar Cell Modules},
author = {M R Vogt and R Witteck and T Gewohn and H Schulte-Huxel and C Schinke and K Bothe and R Brendel},
doi = {10.1364/PVLED.2019.PW2C.1},
year = {2019},
date = {2019-08-02},
booktitle = {OSA Advanced Photonics Congress (AP) 2019 (IPR, Networks, NOMA, SPPCom, PVLED)},
journal = {OSA Advanced Photonics Congress (AP) 2019 (IPR, Networks, NOMA, SPPCom, PVLED)},
pages = {PW2C.1},
publisher = {Optical Society of America},
address = {Burlingame, California, USA},
abstract = {We use the Daidalos-Cloud module ray tracer to quantify optical losses in a PERC+ cell module in three different spectrally resolved irradiance conditions. In mean annual irradiation conditions 8.6 mA/cm² are lost, in contrast to 7.6 mA/cm² in STC.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
We use the Daidalos-Cloud module ray tracer to quantify optical losses in a PERC+ cell module in three different spectrally resolved irradiance conditions. In mean annual irradiation conditions 8.6 mA/cm² are lost, in contrast to 7.6 mA/cm² in STC.
7.
M R Vogt; T Gewohn; K Bothe; R Brendel
Impact of Using Spectrally Resolved Ground Albedo Data for Performance Simulations of Bifacial Modules Proceedings Article
In: WIP, (Hrsg.): Proceedings of the 35th European Photovoltaic Solar Energy Conference and Exhibition, S. 1011-1016, Brussels, Belgium, 2018.
@inproceedings{Vogt2018,
title = {Impact of Using Spectrally Resolved Ground Albedo Data for Performance Simulations of Bifacial Modules},
author = {M R Vogt and T Gewohn and K Bothe and R Brendel},
editor = {WIP},
doi = {10.4229/35thEUPVSEC20182018-5BO.9.5},
year = {2018},
date = {2018-09-24},
booktitle = {Proceedings of the 35th European Photovoltaic Solar Energy Conference and Exhibition},
pages = {1011-1016},
address = {Brussels, Belgium},
abstract = {We simulate the average annual current gain fbif,spe of bifacial PV modules versus monofacial PV modules for various ground albedos and mounting conditions. Our in-house developed ray tracing framework DAIDALOS is used to compute various spectrally resolved rear and front side photon flux. We demonstrate that the annual current gain fbif,spe and as a consequence the energy yield of a bifacial module may vary by up to 35%abs when considering different ground albedos and by up to 10%abs when considering different mounting heights. Considering the difference between using spectrally resolved albedo data and averaged albedo data with respect to wavelength, we find relative deviations in the bifacial gain of up to 19.5%rel. We find that the deviation is reduced to 2.6%rel by weighting the albedo with both the external quantum efficiency of the photovoltaic module and the spectrum.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
We simulate the average annual current gain fbif,spe of bifacial PV modules versus monofacial PV modules for various ground albedos and mounting conditions. Our in-house developed ray tracing framework DAIDALOS is used to compute various spectrally resolved rear and front side photon flux. We demonstrate that the annual current gain fbif,spe and as a consequence the energy yield of a bifacial module may vary by up to 35%abs when considering different ground albedos and by up to 10%abs when considering different mounting heights. Considering the difference between using spectrally resolved albedo data and averaged albedo data with respect to wavelength, we find relative deviations in the bifacial gain of up to 19.5%rel. We find that the deviation is reduced to 2.6%rel by weighting the albedo with both the external quantum efficiency of the photovoltaic module and the spectrum.
8.
H Schulte-Huxel; R Witteck; H Holst; M R Vogt; S Blankemeyer; D Hinken; T Brendemühl; T Dullweber; K Bothe; M Köntges; R Brendel
In: IEEE Journal of Photovoltaics, Bd. 7, Nr. 1, S. 25-31, 2017, ISSN: 2156-3381.
@article{Schulte-Huxel2016,
title = {High-efficiency modules with passivated emitter and rear solar cells an analysis of electrical and optical losses*},
author = {H Schulte-Huxel and R Witteck and H Holst and M R Vogt and S Blankemeyer and D Hinken and T Brendemühl and T Dullweber and K Bothe and M Köntges and R Brendel},
doi = {10.1109/JPHOTOV.2016.2614121},
issn = {2156-3381},
year = {2017},
date = {2017-01-01},
journal = {IEEE Journal of Photovoltaics},
volume = {7},
number = {1},
pages = {25-31},
abstract = {We process a photovoltaic (PV) module with 120 half passivated emitter and rear cells that exhibits an independently confirmed power of 303.2 W and a module efficiency of 20.2% (aperture area). The cells are optimized for operation within the module. We enhance light harvesting from the inactive spacing between the cells and the cell interconnect ribbons. Additionally, we reduce the inactive area to below 3% of the aperture module area. The impact of these measures is analyzed by ray-tracing simulations of the module. Using a numerical model, we analyze and predict the module performance based on the individual cell measurements and the optical simulations. We determine the power loss due to series interconnection of the solar cells to be 1.5%. This is compensated by a gain in current of 1.8% caused by the change of the optical environment of the cells in the module. We achieve a good agreement between simulations and experiments, both showing no cell-to-module power loss.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We process a photovoltaic (PV) module with 120 half passivated emitter and rear cells that exhibits an independently confirmed power of 303.2 W and a module efficiency of 20.2% (aperture area). The cells are optimized for operation within the module. We enhance light harvesting from the inactive spacing between the cells and the cell interconnect ribbons. Additionally, we reduce the inactive area to below 3% of the aperture module area. The impact of these measures is analyzed by ray-tracing simulations of the module. Using a numerical model, we analyze and predict the module performance based on the individual cell measurements and the optical simulations. We determine the power loss due to series interconnection of the solar cells to be 1.5%. This is compensated by a gain in current of 1.8% caused by the change of the optical environment of the cells in the module. We achieve a good agreement between simulations and experiments, both showing no cell-to-module power loss.
9.
M R Vogt; H Schulte-Huxel; M Offer; S Blankemeyer; R Witteck; M Köntges; K Bothe; R Brendel
In: IEEE Journal of Photovoltaics, Bd. 7, Nr. 1, S. 44-50, 2017, ISSN: 2156-3381.
@article{Vogt2017b,
title = {Reduced module operating temperature and increased yield of modules with PERC instead of Al-BSF solar cells},
author = {M R Vogt and H Schulte-Huxel and M Offer and S Blankemeyer and R Witteck and M Köntges and K Bothe and R Brendel},
doi = {10.1109/JPHOTOV.2016.2616191},
issn = {2156-3381},
year = {2017},
date = {2017-01-01},
journal = {IEEE Journal of Photovoltaics},
volume = {7},
number = {1},
pages = {44-50},
abstract = {We demonstrate a reduced operating temperature of modules made from passivated emitter rear cells (PERCs) compared with modules made from cells featuring an unpassivated fullarea screen-printed aluminum rear side metallization aluminum back surface field (Al-BSF). Measurements on specific test modules fabricated from p-type silicon PERC and Al-BSF solar cells reveal a 4 °C lower operating temperature for the PERC module under 1400 W/m2 halogen illumination, if no temperature control is applied. For detailed analysis of the temperature effect, we perform a 3-D ray tracing analysis in the spectral range from 300 to 2500 nm to determine the radiative heat sources in a photovoltaic (PV) module. We combine these heat sources with a 1-D finite element method model solving the coupled system of semiconductor, thermal conduction, convection, and radiation equations for module temperature and power output. The simulations reveal that the origin of the reduced temperature of the PERC modules is a higher efficiency, as well as a higher reflectivity, of the cells rear side mirror. This reduces the parasitic absorptions in the rear metallization and increases the reflection for wavelengths above 1000 nm. This operating temperature difference is simulated to be linear in intensity. The slope depends on the spectral distribution of the incoming light. Under 1000 W/m2 in AM1.5G, our simulations reveal that the operating temperature difference is about 1.7 °C. The operating temperature can be lowered another 3.2 °C, if all parasitic absorption for wavelengths longer than 1200 nm can be prevented. Standard testing conditions applying a temperature control to the module do not show this effect of enhanced performance of the PERC modules. Yield calculations for systems in the field will thus systematically underestimate their electrical power output unless the inherently lower operating temperature of PERC modules is taken into account.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We demonstrate a reduced operating temperature of modules made from passivated emitter rear cells (PERCs) compared with modules made from cells featuring an unpassivated fullarea screen-printed aluminum rear side metallization aluminum back surface field (Al-BSF). Measurements on specific test modules fabricated from p-type silicon PERC and Al-BSF solar cells reveal a 4 °C lower operating temperature for the PERC module under 1400 W/m2 halogen illumination, if no temperature control is applied. For detailed analysis of the temperature effect, we perform a 3-D ray tracing analysis in the spectral range from 300 to 2500 nm to determine the radiative heat sources in a photovoltaic (PV) module. We combine these heat sources with a 1-D finite element method model solving the coupled system of semiconductor, thermal conduction, convection, and radiation equations for module temperature and power output. The simulations reveal that the origin of the reduced temperature of the PERC modules is a higher efficiency, as well as a higher reflectivity, of the cells rear side mirror. This reduces the parasitic absorptions in the rear metallization and increases the reflection for wavelengths above 1000 nm. This operating temperature difference is simulated to be linear in intensity. The slope depends on the spectral distribution of the incoming light. Under 1000 W/m2 in AM1.5G, our simulations reveal that the operating temperature difference is about 1.7 °C. The operating temperature can be lowered another 3.2 °C, if all parasitic absorption for wavelengths longer than 1200 nm can be prevented. Standard testing conditions applying a temperature control to the module do not show this effect of enhanced performance of the PERC modules. Yield calculations for systems in the field will thus systematically underestimate their electrical power output unless the inherently lower operating temperature of PERC modules is taken into account.
10.
H Holst; H Schulte-Huxel; M Winter; S Blankemeyer; R Witteck; M R Vogt; T Booz; F Disterath; M Köntges; K Bothe; R Brendel
In: Energy Procedia, Bd. 92, S. 505-514, 2016, ISSN: 1876-6102, (Proceedings of the 6th International Conference on Crystalline Silicon Photovoltaics (SiliconPV 2016)).
@article{HOLST2016505,
title = {Increased Light Harvesting by Structured Cell Interconnection Ribbons: An Optical Ray Tracing Study Using a Realistic Daylight Model},
author = {H Holst and H Schulte-Huxel and M Winter and S Blankemeyer and R Witteck and M R Vogt and T Booz and F Disterath and M Köntges and K Bothe and R Brendel},
doi = {10.1016/j.egypro.2016.07.134},
issn = {1876-6102},
year = {2016},
date = {2016-08-01},
journal = {Energy Procedia},
volume = {92},
pages = {505-514},
abstract = {A key for increasing the module efficiency is improved light harvesting. The structuring of solar cell interconnection ribbons (CIR) is a promising option for improved light harvesting as it can easily be integrated into current module production. We perform ray tracing simulations of complete PV modules in 3D exhibiting geometric features such as profiled CIR and surface textured cells. We evaluate the increase in module performance by a light harvesting string (LHS) under realistic irradiation conditions with respect to angular and spectral distribution. Using the realistic irradiation for a location in Germany, a location at the polar circle and a location at the equator we simulate the enhancement of short-circuit current density Jsc resulting from the use of LHS. Our results show Jsc gains between 1.00% and 1.86% depending on the location and module orientation. We demonstrate the applicability of our model by comparing measurements and simulations for a one-cell module that we measure and simulate under various angles of the light incidence.v},
note = {Proceedings of the 6th International Conference on Crystalline Silicon Photovoltaics (SiliconPV 2016)},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A key for increasing the module efficiency is improved light harvesting. The structuring of solar cell interconnection ribbons (CIR) is a promising option for improved light harvesting as it can easily be integrated into current module production. We perform ray tracing simulations of complete PV modules in 3D exhibiting geometric features such as profiled CIR and surface textured cells. We evaluate the increase in module performance by a light harvesting string (LHS) under realistic irradiation conditions with respect to angular and spectral distribution. Using the realistic irradiation for a location in Germany, a location at the polar circle and a location at the equator we simulate the enhancement of short-circuit current density Jsc resulting from the use of LHS. Our results show Jsc gains between 1.00% and 1.86% depending on the location and module orientation. We demonstrate the applicability of our model by comparing measurements and simulations for a one-cell module that we measure and simulate under various angles of the light incidence.v
11.
M R Vogt; H Holst; H Schulte-Huxel; S Blankemeyer; R Witteck; D Hinken; M Winter; B Min; C Schinke; M Köntges; K Bothe; R Brendel
In: Energy Procedia, Bd. 92, S. 523-530, 2016, ISSN: 1876-6102, (Proceedings of the 6th International Conference on Crystalline Silicon Photovoltaics (SiliconPV 2016)).
@article{Vogt2016b,
title = {Optical constants of UV transparent EVA and the impact on the PV module output power under realistic illumination},
author = {M R Vogt and H Holst and H Schulte-Huxel and S Blankemeyer and R Witteck and D Hinken and M Winter and B Min and C Schinke and M Köntges and K Bothe and R Brendel},
doi = {10.1016/j.egypro.2016.07.136},
issn = {1876-6102},
year = {2016},
date = {2016-08-01},
journal = {Energy Procedia},
volume = {92},
pages = {523-530},
abstract = {We measure and discuss the complex refractive index of conventional ethylene vinyl acetate (EVA) and an EVA with enhanced UV-transmission based on spectroscopic ellipsometry, transmission and reflection measurements over the wavelength range from 300-1200 nm. Ray tracing of entire solar cell modules using this optical data predicts a 1.3% increase in short circuit current density (Jsc) at standard test conditions for EVA with enhanced UV transmission. This is in good agreement with laboratory experiments of test modules that result in a 1.4% increase in Jsc by using a UV transparent instead of a conventional EVA. Further, ray tracing simulations with realistic irradiation conditions with respect to angular and spectral distribution reveal an even larger Jsc increase of 1.9% in the yearly average. This increase is largest in the summer months with an increase of up to 2.3%.},
note = {Proceedings of the 6th International Conference on Crystalline Silicon Photovoltaics (SiliconPV 2016)},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We measure and discuss the complex refractive index of conventional ethylene vinyl acetate (EVA) and an EVA with enhanced UV-transmission based on spectroscopic ellipsometry, transmission and reflection measurements over the wavelength range from 300-1200 nm. Ray tracing of entire solar cell modules using this optical data predicts a 1.3% increase in short circuit current density (Jsc) at standard test conditions for EVA with enhanced UV transmission. This is in good agreement with laboratory experiments of test modules that result in a 1.4% increase in Jsc by using a UV transparent instead of a conventional EVA. Further, ray tracing simulations with realistic irradiation conditions with respect to angular and spectral distribution reveal an even larger Jsc increase of 1.9% in the yearly average. This increase is largest in the summer months with an increase of up to 2.3%.
12.
M R Vogt; H Hahn; H Holst; M Winter; C Schinke; M Köntges; R Brendel; P P Altermatt
In: IEEE Journal of Photovoltaics, Bd. 6, Nr. 1, S. 111-118, 2016.
@article{Vogt2015b,
title = {Measurement of the optical constants of soda-lime glasses in dependence of iron content, and modeling of iron-related power losses in crystalline Si solar cell modules},
author = {M R Vogt and H Hahn and H Holst and M Winter and C Schinke and M Köntges and R Brendel and P P Altermatt},
doi = {10.1109/JPHOTOV.2015.2498043},
year = {2016},
date = {2016-01-01},
journal = {IEEE Journal of Photovoltaics},
volume = {6},
number = {1},
pages = {111-118},
abstract = {It is well known that the absorbance of soda-lime glass is very sensitive to the amount of iron contamination; therefore, it strongly affects the power output of mass-produced crystalline silicon solar cell modules. We use a combination of ellipsometry and transmission measurements to determine the optical constants, at wavelengths between 300 and 1690 nm, of soda-lime-silica glasses containing an iron content between 1 0/00. and 0.01 0/00., measured with inductive coupled plasma optical emission spectroscopy. We derive two different semiempirical models for the extinction coefficient of soda-lime-silica glass as a function of its iron content: one model for iron alone and the other model for iron including other typical remaining coloring agents. Furthermore, we use ray tracing and spice simulations to predict the power losses in standard modules as a function of iron content in their cover glass sheet. Considering a module with 3.2-mm glass thickness, our results predict a decline in module output power due to iron content in the glass of 1.1% (3 W) for Fe2 O3 = 0.1 0/00. and 9.8% (28 W) for Fe2 O3 = 1 0/00.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
It is well known that the absorbance of soda-lime glass is very sensitive to the amount of iron contamination; therefore, it strongly affects the power output of mass-produced crystalline silicon solar cell modules. We use a combination of ellipsometry and transmission measurements to determine the optical constants, at wavelengths between 300 and 1690 nm, of soda-lime-silica glasses containing an iron content between 1 0/00. and 0.01 0/00., measured with inductive coupled plasma optical emission spectroscopy. We derive two different semiempirical models for the extinction coefficient of soda-lime-silica glass as a function of its iron content: one model for iron alone and the other model for iron including other typical remaining coloring agents. Furthermore, we use ray tracing and spice simulations to predict the power losses in standard modules as a function of iron content in their cover glass sheet. Considering a module with 3.2-mm glass thickness, our results predict a decline in module output power due to iron content in the glass of 1.1% (3 W) for Fe2 O3 = 0.1 0/00. and 9.8% (28 W) for Fe2 O3 = 1 0/00.
13.
M Winter; M Vogt; P P Altermatt; H Holst
Impact of realistic illumination on optical losses in Si solar cell modules compared to standard testing conditions Proceedings Article
In: WIP, (Hrsg.): Proceedings of the 31st European Photovoltaic Solar Energy Conference, S. 1877-1882, Hamburg, Germany, 2015, ISBN: 3-936338-39-6.
@inproceedings{Winter2015,
title = {Impact of realistic illumination on optical losses in Si solar cell modules compared to standard testing conditions},
author = {M Winter and M Vogt and P P Altermatt and H Holst},
editor = {WIP},
doi = {10.4229/EUPVSEC20152015-5DO.11.3},
isbn = {3-936338-39-6},
year = {2015},
date = {2015-09-14},
booktitle = {Proceedings of the 31st European Photovoltaic Solar Energy Conference},
journal = {Proceedings of the 31st European Photovoltaic Solar Energy Conference},
pages = {1877-1882},
address = {Hamburg, Germany},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
14.
M R Vogt; H Holst; M Winter; R Brendel; P P Altermatt
In: Energy Procedia, Bd. 77, S. 215-224, 2015, ISSN: 1876-6102, (5th International Conference on Silicon Photovoltaics, SiliconPV 2015).
@article{VOGT2015215,
title = {Numerical Modeling of c-Si PV Modules by Coupling the Semiconductor with the Thermal Conduction, Convection and Radiation Equations},
author = {M R Vogt and H Holst and M Winter and R Brendel and P P Altermatt},
doi = {10.1016/j.egypro.2015.07.030},
issn = {1876-6102},
year = {2015},
date = {2015-08-28},
journal = {Energy Procedia},
volume = {77},
pages = {215-224},
note = {5th International Conference on Silicon Photovoltaics, SiliconPV 2015},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
15.
M Winter; M Vogt; H Holst; P; Altermatt
In: Optical and Quantum Electronics, Bd. 47, S. 1373-1379, 2015.
@article{Winter2015b,
title = {Combining structures on different length scales in ray tracing: analysis of optical losses in solar cell modules},
author = {M Winter and M Vogt and H Holst and P and Altermatt},
doi = {10.1007/s11082-014-0078-x},
year = {2015},
date = {2015-06-01},
journal = {Optical and Quantum Electronics},
volume = {47},
pages = {1373-1379},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
16.
M Winter; M R Vogt; H Holst; P P Altermatt
Combining structures on different length scales in ray tracing: Analysis of optical losses in solar cell modules Proceedings Article
In: Numerical Simulation of Optoelectronic Devices, 2014, S. 167-168, 2014, ISSN: 2158-3234.
@inproceedings{6935409,
title = {Combining structures on different length scales in ray tracing: Analysis of optical losses in solar cell modules},
author = {M Winter and M R Vogt and H Holst and P P Altermatt},
doi = {10.1109/NUSOD.2014.6935409},
issn = {2158-3234},
year = {2014},
date = {2014-09-01},
booktitle = {Numerical Simulation of Optoelectronic Devices, 2014},
pages = {167-168},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
17.
H Holst; M Winter; M R Vogt; K Bothe; M Köntges; R Brendel; P P Altermatt
In: Energy Procedia, Bd. 38, S. 86-93, 2013, ISSN: 1876-6102, (Proceedings of the 3rd International Conference on Crystalline Silicon Photovoltaics (SiliconPV 2013)).
@article{HOLST201386,
title = {Application of a new ray tracing framework to the analysis of extended regions in Si solar cell modules},
author = {H Holst and M Winter and M R Vogt and K Bothe and M Köntges and R Brendel and P P Altermatt},
doi = {10.1016/j.egypro.2013.07.253},
issn = {1876-6102},
year = {2013},
date = {2013-09-05},
journal = {Energy Procedia},
volume = {38},
pages = {86-93},
note = {Proceedings of the 3rd International Conference on Crystalline Silicon Photovoltaics (SiliconPV 2013)},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
18.
H Holst; P P Altermatt; R Brendel
DAIDALOS – A Plugin Based Framework for Extendable Ray Tracing Proceedings Article
In: WIP, (Hrsg.): 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, S. 2150-2153, Valencia, Spain, 2010, ISBN: 3-936338-26-4.
@inproceedings{Holst2010,
title = {DAIDALOS – A Plugin Based Framework for Extendable Ray Tracing},
author = {H Holst and P P Altermatt and R Brendel},
editor = {WIP},
doi = {10.4229/25thEUPVSEC2010-2CV.3.24},
isbn = {3-936338-26-4},
year = {2010},
date = {2010-09-01},
booktitle = {25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion},
pages = {2150-2153},
address = {Valencia, Spain},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}