Publications
2020 |
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T. Dullweber, M. Stöhr, C. Kruse, F. Haase, M. Rudolph, B. Beier, P. Jäger, V. Mertens, R. Peibst, and R. Brendel Solar Energy Materials and Solar Cells 212 , 110586, (2020), ISSN: 0927-0248. Abstract | Links | BibTeX | Tags: a-Si fingers, Carrier Selective Contacts, PERC, PERC+, POLO, Shadow mask, TOPCon @article{Dullweber2020c,
title = {Evolutionary PERC+ solar cell efficiency projection towards 24% evaluating shadow-mask-deposited poly-Si fingers below the Ag front contact as next improvement step}, author = {T Dullweber and M Stöhr and C Kruse and F Haase and M Rudolph and B Beier and P Jäger and V Mertens and R Peibst and R Brendel}, doi = {10.1016/j.solmat.2020.110586}, issn = {0927-0248}, year = {2020}, date = {2020-08-01}, journal = {Solar Energy Materials and Solar Cells}, volume = {212}, pages = {110586}, abstract = {Monofacial PERC and bifacial PERC + solar cells have become the mainstream solar cell technology exhibiting conversion efficiencies around 22.5% in mass production. We determine a specific saturation current density J0,Ag = 1400 fA/cm2 of the screen-printed Ag front contact. When weighted with the contact area fraction of 3.0% the Ag metal contacts contribute 42 fA/cm2 to the total J0,total = 130 fA/cm2 thereby being a main limitation of the Voc. We investigate carrier selective poly-Si on oxide (POLO) fingers below the screen-printed Ag contacts of PERC + solar cells in order to minimize contact recombination. We name this solar cell PERC + POLO. Numerical simulations reveal that PERC + POLO cells exhibit an efficiency potential up to 24.1% which is 0.3%abs. higher compared to PERC + solar cells. In order to enable low-cost manufacturing of poly-Si fingers, we investigate for the first time the deposition of suitable a-Si fingers by plasma-enhanced chemical vapour deposition (PECVD) through a shadow mask in a vacuum chamber. We demonstrate a-Si fingers as narrow as 70 μm and as high as 250 nm. The parasitic deposition below the mask increases the a-Si finger width by less than 30 μm compared to the mask opening width. First test wafers demonstrate an implied Voc up to 716 mV of PECVD a-Si layers which are crystalized and doped in a subsequent POCl3 diffusion. Applying this process sequence, PERC + POLO cells could be manufactured with the established industrial PERC + process only adding the PECVD deposition of a-Si fingers through a shadow mask.}, keywords = {a-Si fingers, Carrier Selective Contacts, PERC, PERC+, POLO, Shadow mask, TOPCon}, pubstate = {published}, tppubtype = {article} } Monofacial PERC and bifacial PERC + solar cells have become the mainstream solar cell technology exhibiting conversion efficiencies around 22.5% in mass production. We determine a specific saturation current density J0,Ag = 1400 fA/cm2 of the screen-printed Ag front contact. When weighted with the contact area fraction of 3.0% the Ag metal contacts contribute 42 fA/cm2 to the total J0,total = 130 fA/cm2 thereby being a main limitation of the Voc. We investigate carrier selective poly-Si on oxide (POLO) fingers below the screen-printed Ag contacts of PERC + solar cells in order to minimize contact recombination. We name this solar cell PERC + POLO. Numerical simulations reveal that PERC + POLO cells exhibit an efficiency potential up to 24.1% which is 0.3%abs. higher compared to PERC + solar cells. In order to enable low-cost manufacturing of poly-Si fingers, we investigate for the first time the deposition of suitable a-Si fingers by plasma-enhanced chemical vapour deposition (PECVD) through a shadow mask in a vacuum chamber. We demonstrate a-Si fingers as narrow as 70 μm and as high as 250 nm. The parasitic deposition below the mask increases the a-Si finger width by less than 30 μm compared to the mask opening width. First test wafers demonstrate an implied Voc up to 716 mV of PECVD a-Si layers which are crystalized and doped in a subsequent POCl3 diffusion. Applying this process sequence, PERC + POLO cells could be manufactured with the established industrial PERC + process only adding the PECVD deposition of a-Si fingers through a shadow mask.
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R. Brendel, R. Niepelt, D. Bredemeier, and P. Pärisch Niedersachsen in die Sonne: Die Solarenergie in der Energiewende Presentation/Poster Online, 23.06.2020, (3. Niedersächsisches Forum Solarenergie). BibTeX | Tags: Energiewende @misc{Brendel2020,
title = {Niedersachsen in die Sonne: Die Solarenergie in der Energiewende}, author = {R Brendel and R Niepelt and D Bredemeier and P Pärisch}, year = {2020}, date = {2020-06-23}, address = {Online}, note = {3. Niedersächsisches Forum Solarenergie}, keywords = {Energiewende}, pubstate = {published}, tppubtype = {presentation} } |
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P. Pärisch, and B. Chhugani Initiative zur Marktetablierung und Verbreitung von Anlagen zur thermisch-elektrischen Energieversorgung mittels PVT-Kollektoren und Wärmepumpen im Gebäudesektor – integraTE Presentation/Poster Online Meeting, 17.06.2020, (3. Projekteforum EnEff.Gebäude.2050). @misc{Pärisch2020b,
title = {Initiative zur Marktetablierung und Verbreitung von Anlagen zur thermisch-elektrischen Energieversorgung mittels PVT-Kollektoren und Wärmepumpen im Gebäudesektor – integraTE}, author = {P Pärisch and B Chhugani}, year = {2020}, date = {2020-06-17}, address = {Online Meeting}, note = {3. Projekteforum EnEff.Gebäude.2050}, keywords = {PVT}, pubstate = {published}, tppubtype = {presentation} } |
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S. Gharibzadeh, I. M. Hossain, P. Fassl, A. Mertens, S. Schafer, M. Rienacker, T. Wietler, R. Peibst, U. Lemmer, B. S. Richards, and U. W. Paetzold 2D Surface Passivation in Semi-transparent Perovskite Top Solar Cells with Engineered Bandgap for Tandem Photovoltaics Presentation/Poster 17.06.2020, (IEEE 47th PVSC Virtual Meeting). Abstract | BibTeX | Tags: Tandem @misc{Gharibzadeh2020b,
title = {2D Surface Passivation in Semi-transparent Perovskite Top Solar Cells with Engineered Bandgap for Tandem Photovoltaics}, author = {S Gharibzadeh and I M Hossain and P Fassl and A Mertens and S Schafer and M Rienacker and T Wietler and R Peibst and U Lemmer and B S Richards and U W Paetzold}, year = {2020}, date = {2020-06-17}, abstract = {Wide-bandgap perovskite top solar cells with optimal bandgap (Eg) are key to boost the efficiency of perovskite/Si tandem devices beyond the Shockley–Queisser limit for single-junction solar cells. In this work, semi-transparent double-cation wide-bandgap perovskite solar cells (PSCs) with engineered bandgap are passivated by employing a 2D/3D perovskite heterostructure. We observe a 45 mV enhancement in open circuit voltage for all investigated bandgaps compared to reference devices without the heterostructure. This is attributed to reduced non-radiative recombination losses at the interface toward the hole-transporting layer. With this approach, efficient four-terminal (4T) perovskite/Si tandem solar cells with a stabilized power conversion efficiency (PCE) of 25.7% are demonstrated. Moreover, it is experimentally shown for the first time that a broad range of bandgaps of the top PSCs are suitable for attaining high-efficiency 4T tandem devices. In order to improve the PCE further, we present indium zinc oxide (IZO) as an alternative rear transparent conductive oxide. }, note = {IEEE 47th PVSC Virtual Meeting}, keywords = {Tandem}, pubstate = {published}, tppubtype = {presentation} } Wide-bandgap perovskite top solar cells with optimal bandgap (Eg) are key to boost the efficiency of perovskite/Si tandem devices beyond the Shockley–Queisser limit for single-junction solar cells. In this work, semi-transparent double-cation wide-bandgap perovskite solar cells (PSCs) with engineered bandgap are passivated by employing a 2D/3D perovskite heterostructure. We observe a 45 mV enhancement in open circuit voltage for all investigated bandgaps compared to reference devices without the heterostructure. This is attributed to reduced non-radiative recombination losses at the interface toward the hole-transporting layer. With this approach, efficient four-terminal (4T) perovskite/Si tandem solar cells with a stabilized power conversion efficiency (PCE) of 25.7% are demonstrated. Moreover, it is experimentally shown for the first time that a broad range of bandgaps of the top PSCs are suitable for attaining high-efficiency 4T tandem devices. In order to improve the PCE further, we present indium zinc oxide (IZO) as an alternative rear transparent conductive oxide.
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C. Hollemann, F. Haase, J. Krugener, R. Brendel, and R. Peibst Firing stability of n-type poly Si on oxide junctions Presentation/Poster 15.06.2020, (IEEE 47th PVSC Virtual Meeting). Abstract | BibTeX | Tags: POLO @misc{Hollemann2020b,
title = {Firing stability of n-type poly Si on oxide junctions}, author = {C Hollemann and F Haase and J Krugener and R Brendel and R Peibst}, year = {2020}, date = {2020-06-15}, abstract = {Passivated contacts by poly-Si on oxide (POLO) junctions yield high passivation qualities after an appropriate annealing process at temperatures between 800°C and 1050°C. In today's typical cell production, a second, high temperature process is applied during ‘firing’. Firing is commonly used together with screen printed contacts in industrial production. Thus, a high stability of the passivation quality against this firing process is highly desirable – and also expected since the previous high-temperature process implies a much higher thermal budget. However, in this work we found a significant decrease in effective lifetimes of up to 75% for n-type POLO samples with thin interfacial oxide at firing temperatures of 620°C to 900°C. This holds without a supply of hydrogen (no capping layers). Experiments with hydrogen-rich dielectric capping layers show, however, that a coating with AlOx as opposed to SiNy, can significantly increase the stability of the passivation. Capacitance-voltage measurements show that the saturation current density correlates to the density of defect states at the SiOx/c-Si interface when varying the firing temperature. Although firing with hydrogen supplying layers seems to be viable, our results may indicate that the chemical configuration of the SiOx/Si interface changes from Si-O to Si-H bonds upon firing. If this hypothesis holds true, possible implications on the long-term stability of the passivation quality should be evaluated.}, note = {IEEE 47th PVSC Virtual Meeting}, keywords = {POLO}, pubstate = {published}, tppubtype = {presentation} } Passivated contacts by poly-Si on oxide (POLO) junctions yield high passivation qualities after an appropriate annealing process at temperatures between 800°C and 1050°C. In today's typical cell production, a second, high temperature process is applied during ‘firing’. Firing is commonly used together with screen printed contacts in industrial production. Thus, a high stability of the passivation quality against this firing process is highly desirable – and also expected since the previous high-temperature process implies a much higher thermal budget. However, in this work we found a significant decrease in effective lifetimes of up to 75% for n-type POLO samples with thin interfacial oxide at firing temperatures of 620°C to 900°C. This holds without a supply of hydrogen (no capping layers). Experiments with hydrogen-rich dielectric capping layers show, however, that a coating with AlOx as opposed to SiNy, can significantly increase the stability of the passivation. Capacitance-voltage measurements show that the saturation current density correlates to the density of defect states at the SiOx/c-Si interface when varying the firing temperature. Although firing with hydrogen supplying layers seems to be viable, our results may indicate that the chemical configuration of the SiOx/Si interface changes from Si-O to Si-H bonds upon firing. If this hypothesis holds true, possible implications on the long-term stability of the passivation quality should be evaluated.
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G. Wetzel, L. Salomon, J. Krügener, and R. Peibst Specifications for maximum power point tracking in vehicle-integrated photovoltaics based on high-resolution transient irradiance measurements Presentation/Poster 15.06.2020, (IEEE 47th PVSC Virtual Meeting). Abstract | BibTeX | Tags: VIPV @misc{Wetzel2020,
title = {Specifications for maximum power point tracking in vehicle-integrated photovoltaics based on high-resolution transient irradiance measurements}, author = {G Wetzel and L Salomon and J Krügener and R Peibst}, year = {2020}, date = {2020-06-15}, abstract = {Vehicle integrated photovoltaic (VIPV) systems have much different requirements on maximum power tracking compared to stationary setups. Especially the occurrence of fast changes between full irradiance and shading are demanding. In order to evaluate the specific impact of these conditions on VIPV system performance, we conducted high time resolution measurements of the irradiance on the roof and sides of a vehicle during driving in an urban environment. We found that the average irradiance on the sides is only about a third of that on the roof. We also found that changes in illumination occur predominantly at lower frequencies and less than 2% of the irradiance occurs at 5 Hz or higher. Therefore maximum power point tracker design must consider short-period changes in power. We also measured the cell voltage of silicon hetero junction solar cells under transient illumination. We find that the cell voltage can follow transient illumination at those frequencies easily.}, note = {IEEE 47th PVSC Virtual Meeting}, keywords = {VIPV}, pubstate = {published}, tppubtype = {presentation} } Vehicle integrated photovoltaic (VIPV) systems have much different requirements on maximum power tracking compared to stationary setups. Especially the occurrence of fast changes between full irradiance and shading are demanding. In order to evaluate the specific impact of these conditions on VIPV system performance, we conducted high time resolution measurements of the irradiance on the roof and sides of a vehicle during driving in an urban environment. We found that the average irradiance on the sides is only about a third of that on the roof. We also found that changes in illumination occur predominantly at lower frequencies and less than 2% of the irradiance occurs at 5 Hz or higher. Therefore maximum power point tracker design must consider short-period changes in power. We also measured the cell voltage of silicon hetero junction solar cells under transient illumination. We find that the cell voltage can follow transient illumination at those frequencies easily.
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E. L. Warren, W. E. McMahon, M. Rienaecker, K. T. VanSant, R. C. Whitehead, R. Peibst, and A. C. Tamboli Fundamentals of three-terminal tandem solar cells: a comprehensive taxonomy Presentation/Poster 15.06.2020, (IEEE 47th PVSC Virtual Meeting). Abstract | BibTeX | Tags: Tandem @misc{Warren2020b,
title = {Fundamentals of three-terminal tandem solar cells: a comprehensive taxonomy}, author = {E L Warren and W E McMahon and M Rienaecker and K T VanSant and R C Whitehead and R Peibst and A C Tamboli}, year = {2020}, date = {2020-06-15}, abstract = {Three-terminal tandem (3TT) solar cells can overcome some of the limitations of two- and four-terminal tandem designs. However, the coupled nature of the cells adds a degree of complexity to the devices themselves and the ways that their performance can be measured and reported. Although there are many different ways to fabricate 3TT devices, no standard nomenclature nor taxonomic framework exists, and this hinders both fundamental understanding and comparison of the various designs. To facilitate understanding, we have developed a taxonomy which encompasses all types of 3TT devices, enabling a common nomenclature for discussing devices and performance. Once the physical devices, contact nodes, and loading circuitry have been self-consistently described, it becomes apparent that a wide range of 3TT devices share a common set of design and operating principles. A standard naming system to describe cell components and contacts also facilitates equivalent-circuit modeling, which is needed to understand device performance and multi-cell interconnections.}, Three-terminal tandem (3TT) solar cells can overcome some of the limitations of two- and four-terminal tandem designs. However, the coupled nature of the cells adds a degree of complexity to the devices themselves and the ways that their performance can be measured and reported. Although there are many different ways to fabricate 3TT devices, no standard nomenclature nor taxonomic framework exists, and this hinders both fundamental understanding and comparison of the various designs.
To facilitate understanding, we have developed a taxonomy which encompasses all types of 3TT devices, enabling a common nomenclature for discussing devices and performance. Once the physical devices, contact nodes, and loading circuitry have been self-consistently described, it becomes apparent that a wide range of 3TT devices share a common set of design and operating principles. A standard naming system to describe cell components and contacts also facilitates equivalent-circuit modeling, which is needed to understand device performance and multi-cell interconnections. |
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W. E. McMahon, H. Schulte-Huxel, J. Buencuerpo, M. S. Young, T. R. Klein, J. F. Geisz, A. C. Tamboli, and E. L. Warren Voltage-Matched Strings using 3-Terminal Tandems: Fundamentals and End Losses Presentation/Poster 15.06.2020, (IEEE 47th PVSC Virtual Meeting). Abstract | BibTeX | Tags: 3-Terminal Tandem @misc{McMahon2020,
title = {Voltage-Matched Strings using 3-Terminal Tandems: Fundamentals and End Losses}, author = {W E McMahon and H Schulte-Huxel and J Buencuerpo and M S Young and T R Klein and J F Geisz and A C Tamboli and E L Warren}, year = {2020}, date = {2020-06-15}, abstract = {Strings constructed from 3-terminal tandem (3TT) cells can provide some of the performance benefits of voltage-matching with less cell complexity than strings based on 4-terminal tandem cells. However, the circuitry for a 3TT string can become more complex, making circuit analysis more challenging. Here we illustrate the essential features of "single-polarity" voltage-matched (VM) 3TT strings using representative examples. End losses are intrinsic to this type of string, but can be reduced by minimizing m and n in the Vtop/Vbot VM ratio m/n, and further mitigated by increasing the string length. This analysis agrees with preliminary experimental results.}, note = {IEEE 47th PVSC Virtual Meeting}, keywords = {3-Terminal Tandem}, pubstate = {published}, tppubtype = {presentation} } Strings constructed from 3-terminal tandem (3TT) cells can provide some of the performance benefits of voltage-matching with less cell complexity than strings based on 4-terminal tandem cells. However, the circuitry for a 3TT string can become more complex, making circuit analysis more challenging. Here we illustrate the essential features of "single-polarity" voltage-matched (VM) 3TT strings using representative examples. End losses are intrinsic to this type of string, but can be reduced by minimizing m and n in the Vtop/Vbot VM ratio m/n, and further mitigated by increasing the string length. This analysis agrees with preliminary experimental results.
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G. M. Wilson, M. M. Al-Jassim, W. K. Metzger, S. W. Glunz, P. Verlinden, X. Gang, L. M. Mansfield, B. J. Stanbery, K. Zhu, Y. Yan, J. J. Berry, A. J. Ptak, F. Dimroth, B. M. Kayes, A. C. Tamboli, R. Peibst, K. R. Catchpole, M. Reese, C. Klinga, P. Denholm, M. Morjaria, M. G. Deceglie, J. M. Freeman, M. A. Mikofski, D. C. Jordan, G. TamizhMani, and D. B. Sulas The 2020 Photovoltaic Technologies Roadmap Journal Article Forthcoming Journal of Physics D: Applied Physics Forthcoming. Abstract | Links | BibTeX | Tags: solar @article{Wilson2020,
title = {The 2020 Photovoltaic Technologies Roadmap}, author = {G M Wilson and M M Al-Jassim and W K Metzger and S W Glunz and P Verlinden and X Gang and L M Mansfield and B J Stanbery and K Zhu and Y Yan and J J Berry and A J Ptak and F Dimroth and B M Kayes and A C Tamboli and R Peibst and K R Catchpole and M Reese and C Klinga and P Denholm and M Morjaria and M G Deceglie and J M Freeman and M A Mikofski and D C Jordan and G TamizhMani and D B Sulas}, doi = {10.1088/1361-6463/ab9c6a}, year = {2020}, date = {2020-06-12}, journal = {Journal of Physics D: Applied Physics}, abstract = {Over the past decade, the global cumulative installed photovoltaic (PV) capacity has grown exponentially, reaching 591 GW in 2019. Rapid progress was driven in large part by improvements in solar cell and module efficiencies, reduction in manufacturing costs and the realization of levelized costs of electricity that are now generally less than other energy sources and approaching similar costs with storage included. Given this success, it is a particularly fitting time to assess the state of the photovoltaics field and the technology milestones that must be achieved to maximize future impact and forward momentum. This roadmap outlines the critical areas of development in all of the major PV conversion technologies, advances needed to enable terawatt-scale PV installation, and cross-cutting topics on reliability, characterization, and applications. Each perspective provides a status update, summarizes the limiting immediate and long-term technical challenges and highlights breakthroughs that are needed to address them. In total, this roadmap is intended to guide researchers, funding agencies and industry in identifying the areas of development that will have the most impact on PV technology in the upcoming years.}, keywords = {solar}, pubstate = {forthcoming}, tppubtype = {article} } Over the past decade, the global cumulative installed photovoltaic (PV) capacity has grown exponentially, reaching 591 GW in 2019. Rapid progress was driven in large part by improvements in solar cell and module efficiencies, reduction in manufacturing costs and the realization of levelized costs of electricity that are now generally less than other energy sources and approaching similar costs with storage included. Given this success, it is a particularly fitting time to assess the state of the photovoltaics field and the technology milestones that must be achieved to maximize future impact and forward momentum. This roadmap outlines the critical areas of development in all of the major PV conversion technologies, advances needed to enable terawatt-scale PV installation, and cross-cutting topics on reliability, characterization, and applications. Each perspective provides a status update, summarizes the limiting immediate and long-term technical challenges and highlights breakthroughs that are needed to address them. In total, this roadmap is intended to guide researchers, funding agencies and industry in identifying the areas of development that will have the most impact on PV technology in the upcoming years.
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B. Schiebler, F. Weiland, F. Giovannetti, O. Kastner, and S. Jack Improved flat plate collector with heat pipesfor overheating prevention in solar thermal systems Inproceedings Proceedings ISES Solar World Congress 2019 / IEA SHC International Conference on Solar Heating and Cooling for Buildings and Industry 2019, 61-72, (2020). Abstract | Links | BibTeX | Tags: Flat plate collector, heat pipe, overheating prevention, stagnation temperature @inproceedings{Schiebler2020,
title = {Improved flat plate collector with heat pipesfor overheating prevention in solar thermal systems}, author = {B Schiebler and F Weiland and F Giovannetti and O Kastner and S Jack}, doi = {10.18086/swc.2019.01.08}, year = {2020}, date = {2020-06-10}, booktitle = {Proceedings ISES Solar World Congress 2019 / IEA SHC International Conference on Solar Heating and Cooling for Buildings and Industry 2019}, pages = {61-72}, abstract = {Heat pipes in solar thermal collectors can reduce thermal loads in the solar circuit by using the physical effect of dry-out limitation. By avoiding high temperatures and vapor formation, simplified, more reliable and cost effective solar thermal systems can be designed. This paper presents a theoretical study ondifferentheat pipe andmanifoldconfigurationsfor flat plate collectors. The focus is ona highthermal efficiency in the operating rangeand a significant temperature limitation in stagnation mode. Several prototype collectorsaremanufactured and experimentallyinvestigated by means of indoor performance measurements. Thereby,a conversion factor of 73%isreported, whichrepresents an increase of 4percentage pointscompared to a previous prototype. Duringstagnationeventswe localizea maximum fluid temperature about130°C within the manifold, whichdecreases to values below 100°C towardsthe collector connections.Finally, we evaluate the system performance of the prototypewithanexemplary solar DHW-systemby means of dynamic TRNSYS-simulations. The results show that the calculated annual yield ispredictedonly 5% lower than the one of a comparabledirect flow collectorand critical stagnation eventscan be fully avoided.}, keywords = {Flat plate collector, heat pipe, overheating prevention, stagnation temperature}, pubstate = {published}, tppubtype = {inproceedings} } Heat pipes in solar thermal collectors can reduce thermal loads in the solar circuit by using the physical effect of dry-out limitation. By avoiding high temperatures and vapor formation, simplified, more reliable and cost effective solar thermal systems can be designed. This paper presents a theoretical study ondifferentheat pipe andmanifoldconfigurationsfor flat plate collectors. The focus is ona highthermal efficiency in the operating rangeand a significant temperature limitation in stagnation mode. Several prototype collectorsaremanufactured and experimentallyinvestigated by means of indoor performance measurements. Thereby,a conversion factor of 73%isreported, whichrepresents an increase of 4percentage pointscompared to a previous prototype. Duringstagnationeventswe localizea maximum fluid temperature about130°C within the manifold, whichdecreases to values below 100°C towardsthe collector connections.Finally, we evaluate the system performance of the prototypewithanexemplary solar DHW-systemby means of dynamic TRNSYS-simulations. The results show that the calculated annual yield ispredictedonly 5% lower than the one of a comparabledirect flow collectorand critical stagnation eventscan be fully avoided.
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F. Giovannetti, C. Lampe, M. Kirchner, M. Littwin, S. Asenbeck, and S. Fische Experimental Investigations on Photovoltaic-Thermal Arrays Designed for the Use as Heat Pump Source Inproceedings Proceedings ISES Solar World Congress 2019 / IEA SHC International Conference on Solar Heating and Cooling for Buildings and Industry 2019, 177-188, (2020). Abstract | Links | BibTeX | Tags: field test, heat exchanger, heat pump, heat transfer coefficient, Photovoltaic-thermal collector @inproceedings{Giovannetti2020,
title = {Experimental Investigations on Photovoltaic-Thermal Arrays Designed for the Use as Heat Pump Source}, author = {F Giovannetti and C Lampe and M Kirchner and M Littwin and S Asenbeck and S Fische}, doi = {10.18086/swc.2019.05.03}, year = {2020}, date = {2020-06-10}, booktitle = {Proceedings ISES Solar World Congress 2019 / IEA SHC International Conference on Solar Heating and Cooling for Buildings and Industry 2019}, pages = {177-188}, abstract = {Uncovered, liquid-basedphotovoltaic-thermal (PV-T) collectors can becombined withground-coupled heat pump systems for different purposes: toincrease the evaporator temperature,to regenerate geothermal resourcesor for pre-heatingdomestic hot water. Thispaperexperimentally investigates the behavior of a novel PV-T panelwith enhancedambient heat transfer propertiesandprimarily conceived for the operation as the sole heat source for brine-to-water compression heat pumps. After presenting the results of the thermal efficiency measurement of the panel, which attest itsunusual parameters (c1= 23W/m²K, c3= 7.6J/m³K, c6= 0.1s/m),we report onthe long-term performance tests carried out on large roof-mounted PV-T fields at two different locationsin Germany. The investigation focuseson the impact of real environmentalandinstallation conditions on the performanceof the field as ambient heat exchanger,operating at fluid temperatures below ambient air temperature. The results confirmthehigh overall heat transfer coefficient Uof the field,up to 40 W/m²K,which isreduced by about20%in comparison to the U-value determined for thesingle panel, however. The reduction can be attributed to a largeextent to the high sensitivity of the collector design to convective heat transfer mechanismsand to the different wind exposure during the tests.For the same reasons we report a 30% decrease in the U-value compared to the basic configuration by usingjoint plates to cover the gaps of the field with the aim of improvingthe reliability and aestheticsof the installation.}, keywords = {field test, heat exchanger, heat pump, heat transfer coefficient, Photovoltaic-thermal collector}, pubstate = {published}, tppubtype = {inproceedings} } Uncovered, liquid-basedphotovoltaic-thermal (PV-T) collectors can becombined withground-coupled heat pump systems for different purposes: toincrease the evaporator temperature,to regenerate geothermal resourcesor for pre-heatingdomestic hot water. Thispaperexperimentally investigates the behavior of a novel PV-T panelwith enhancedambient heat transfer propertiesandprimarily conceived for the operation as the sole heat source for brine-to-water compression heat pumps. After presenting the results of the thermal efficiency measurement of the panel, which attest itsunusual parameters (c1= 23W/m²K, c3= 7.6J/m³K, c6= 0.1s/m),we report onthe long-term performance tests carried out on large roof-mounted PV-T fields at two different locationsin Germany. The investigation focuseson the impact of real environmentalandinstallation conditions on the performanceof the field as ambient heat exchanger,operating at fluid temperatures below ambient air temperature. The results confirmthehigh overall heat transfer coefficient Uof the field,up to 40 W/m²K,which isreduced by about20%in comparison to the U-value determined for thesingle panel, however. The reduction can be attributed to a largeextent to the high sensitivity of the collector design to convective heat transfer mechanismsand to the different wind exposure during the tests.For the same reasons we report a 30% decrease in the U-value compared to the basic configuration by usingjoint plates to cover the gaps of the field with the aim of improvingthe reliability and aestheticsof the installation.
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P. Pärisch, N. van der Veer, M. Kirchner, F. Giovannetti, and C. Lampe COMFORT ASSESSMENT OF TANKLESS WATER HEATERS: REVIEW AND SUGGESTIONS Inproceedings Proceedings ISES Solar World Congress 2019 / IEA SHC International Conference on Solar Heating and Cooling for Buildings and Industry 2019, 246-257, (2020). Abstract | BibTeX | Tags: comfort assessment, domestic hot water modules, perception, pipe model, tankless water heaters @inproceedings{Pärisch2020,
title = {COMFORT ASSESSMENT OF TANKLESS WATER HEATERS: REVIEW AND SUGGESTIONS}, author = {P Pärisch and N van der Veer and M Kirchner and F Giovannetti and C Lampe }, year = {2020}, date = {2020-06-10}, booktitle = {Proceedings ISES Solar World Congress 2019 / IEA SHC International Conference on Solar Heating and Cooling for Buildings and Industry 2019}, pages = {246-257}, abstract = {Today, a European standard procedure for the assessment of the comfort properties of domestic hot water modules is not available. Preliminary work on this subject is existing, though: Several years ago, the Swiss research institute SPF has suggested a procedure regarding the withdrawal capacity, energy efficiency and comfort, which is sometimes regarded as preliminary state-of-the-art version of an upcoming standardization procedure to be defined in the future. On this background, this paper discusses strategies for the assessment of the comfort properties of domestic hot water modules in terms of the control performance of adopting tapping events. The assessment is based on recorded temperature data, numerically damped by a simulation model for a generic pipe section. This model yields tapping temperatures, which are assessed by means of comfort criteria regarding both the temperature value as well as its rate of change. As tapping comfort measure, we propose the heat fraction during the first 60 seconds of a tapping event that is described as “comfortable” as a comfort figure. }, keywords = {comfort assessment, domestic hot water modules, perception, pipe model, tankless water heaters}, pubstate = {published}, tppubtype = {inproceedings} } Today, a European standard procedure for the assessment of the comfort properties of domestic hot water modules is not available. Preliminary work on this subject is existing, though: Several years ago, the Swiss research institute SPF has suggested a procedure regarding the withdrawal capacity, energy efficiency and comfort, which is sometimes regarded as preliminary state-of-the-art version of an upcoming standardization procedure to be defined in the future. On this background, this paper discusses strategies for the assessment of the comfort properties of domestic hot water modules in terms of the control performance of adopting tapping events. The assessment is based on recorded temperature data, numerically damped by a simulation model for a generic pipe section. This model yields tapping temperatures, which are assessed by means of comfort criteria regarding both the temperature value as well as its rate of change. As tapping comfort measure, we propose the heat fraction during the first 60 seconds of a tapping event that is described as “comfortable” as a comfort figure.
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F. Haase What’s behind the high potential of passivated contact solar cells Presentation/Poster Online, 09.06.2020, (TaiyangNews). BibTeX | Tags: Passivated Contact @misc{Haase2020,
title = {What’s behind the high potential of passivated contact solar cells}, author = {F Haase}, year = {2020}, date = {2020-06-09}, address = {Online}, note = {TaiyangNews}, keywords = {Passivated Contact}, pubstate = {published}, tppubtype = {presentation} } |
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R. Peibst, C. Kruse, S. Schäfer, V. Mertens, S. Bordihn, T. Dullweber, F. Haase, C. Hollemann, B. Lim, B. Min, R. Niepelt, H. Schulte-Huxel, and R. Brendel For none, one, or two polarities—How do POLO junctions fit best into industrial Si solar cells? Journal Article Progress in Photovoltaics: Research and Applications 28 (6), 503-516, (2020). Abstract | Links | BibTeX | Tags: efficiency potential, passivating contacts, POLO, Poly-Si, solar cell development @article{Peibst2020,
title = {For none, one, or two polarities—How do POLO junctions fit best into industrial Si solar cells?}, author = {R Peibst and C Kruse and S Schäfer and V Mertens and S Bordihn and T Dullweber and F Haase and C Hollemann and B Lim and B Min and R Niepelt and H Schulte-Huxel and R Brendel}, doi = {10.1002/pip.3201}, year = {2020}, date = {2020-06-01}, journal = {Progress in Photovoltaics: Research and Applications}, volume = {28}, number = {6}, pages = {503-516}, abstract = {Abstract We present a systematic study on the benefit of the implementation of poly-Si on oxide (POLO) or related junctions into p-type industrial Si solar cells as compared with the benchmark of Passivated Emitter and Rear Cell (PERC). We assess three aspects: (a) the simulated efficiency potential of representative structures with POLO junctions for none (=PERC+), one, and for two polarities; (b) possible lean process flows for their fabrication; and (c) experimental results on major building blocks. Synergistic efficiency gain analysis reveals that the exclusive suppression of the contact recombination for one polarity by POLO only yields moderate efficiency improvements between 0.23%abs and 0.41%abs as compared with PERC+ because of the remaining recombination paths. This problem is solved in a structure that includes POLO junctions for both polarities (POLO2), for whose realization we propose a lean process flow, and for which we experimentally demonstrate the most important building blocks. However, two experimental challenges—alignment tolerances and screen-print metallization of p+ poly-Si—are unsolved so far and reduced the efficiency of the “real” POLO2 cell as compared with an idealized scenario. As an intermediate step, we therefore work on a POLO IBC cell with POLO junctions for one polarity. It avoids the abovementioned challenges of the POLO2 structure, can be realized within a lean process flow, and has an efficiency benefit of 1.59%abs as compared with PERC—because not only contact recombination is suppressed but also the entire phosphorus emitter is replaced by an n+ POLO junction.}, keywords = {efficiency potential, passivating contacts, POLO, Poly-Si, solar cell development}, pubstate = {published}, tppubtype = {article} } Abstract We present a systematic study on the benefit of the implementation of poly-Si on oxide (POLO) or related junctions into p-type industrial Si solar cells as compared with the benchmark of Passivated Emitter and Rear Cell (PERC). We assess three aspects: (a) the simulated efficiency potential of representative structures with POLO junctions for none (=PERC+), one, and for two polarities; (b) possible lean process flows for their fabrication; and (c) experimental results on major building blocks. Synergistic efficiency gain analysis reveals that the exclusive suppression of the contact recombination for one polarity by POLO only yields moderate efficiency improvements between 0.23%abs and 0.41%abs as compared with PERC+ because of the remaining recombination paths. This problem is solved in a structure that includes POLO junctions for both polarities (POLO2), for whose realization we propose a lean process flow, and for which we experimentally demonstrate the most important building blocks. However, two experimental challenges—alignment tolerances and screen-print metallization of p+ poly-Si—are unsolved so far and reduced the efficiency of the “real” POLO2 cell as compared with an idealized scenario. As an intermediate step, we therefore work on a POLO IBC cell with POLO junctions for one polarity. It avoids the abovementioned challenges of the POLO2 structure, can be realized within a lean process flow, and has an efficiency benefit of 1.59%abs as compared with PERC—because not only contact recombination is suppressed but also the entire phosphorus emitter is replaced by an n+ POLO junction.
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K. Sporleder, S. Großer, C. Hagendorf, V. Naumann, H. Schulte-Huxel, N. Schüler, and M. Turek Potential-induced Degradation - At the Rear Side of Bifacial Passivated Emitter and Rear Cells Presentation/Poster Online, 01.06.2020, (SiliconPV 2020 Video Presentations). @misc{Sporleder2020,
title = {Potential-induced Degradation - At the Rear Side of Bifacial Passivated Emitter and Rear Cells}, author = {K Sporleder and S Großer and C Hagendorf and V Naumann and H Schulte-Huxel and N Schüler and M Turek}, year = {2020}, date = {2020-06-01}, address = {Online}, note = {SiliconPV 2020 Video Presentations}, keywords = {PID}, pubstate = {published}, tppubtype = {presentation} } |
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M. Littwin, B. Chhugani, C. Lampe, M. Kirchner, F. Giovannetti, and P. Pärisch PVT-Systeme: Hardware-in-the-loop Tests und TRNSYS Jahressimulationen Inproceedings Conexio. GmbH (Ed.): Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme, 67-79, Online Symposium, (2020). @inproceedings{Littwin2020,
title = {PVT-Systeme: Hardware-in-the-loop Tests und TRNSYS Jahressimulationen}, author = {M Littwin and B Chhugani and C Lampe and M Kirchner and F Giovannetti and P Pärisch}, editor = {Conexio GmbH}, year = {2020}, date = {2020-05-15}, booktitle = {Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme}, pages = {67-79}, address = {Online Symposium}, keywords = {PVT}, pubstate = {published}, tppubtype = {inproceedings} } |
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S. Helmling, K. Kramer, S. Fischer, H. Drück, P. Pärisch, F. Giovanetti, and B. Epp Initiative zur Marktetablierung und Verbreitung von Anlagen zur thermisch-elektrischen Energieversorgung mittels PVT-Kollektoren und Wärmepumpen im Gebäudesektor - integraTE Inproceedings Conexio. GmbH (Ed.): Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme, 257, Online Symposium, (2020). @inproceedings{Helmling2020b,
title = {Initiative zur Marktetablierung und Verbreitung von Anlagen zur thermisch-elektrischen Energieversorgung mittels PVT-Kollektoren und Wärmepumpen im Gebäudesektor - integraTE}, author = {S Helmling and K Kramer and S Fischer and H Drück and P Pärisch and F Giovanetti and B Epp}, editor = {Conexio GmbH}, year = {2020}, date = {2020-05-15}, booktitle = {Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme}, pages = {257}, address = {Online Symposium}, keywords = {PVT}, pubstate = {published}, tppubtype = {inproceedings} } |
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F. Weiland, M. Kirchner, F. Hüsing, and F. Giovannetti Solare Stahl-Sandwichelemente im Industrie- und Gewerbebau: Systemsimulationen zur Potentialanalyse Inproceedings Conexio. GmbH (Ed.): Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme, 421-434, Online Symposium, (2020). BibTeX | Tags: Sandwichelemente @inproceedings{Weiland2020b,
title = {Solare Stahl-Sandwichelemente im Industrie- und Gewerbebau: Systemsimulationen zur Potentialanalyse}, author = {F Weiland and M Kirchner and F Hüsing and F Giovannetti}, editor = {Conexio GmbH}, year = {2020}, date = {2020-05-15}, booktitle = {Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme}, pages = {421-434}, address = {Online Symposium}, keywords = {Sandwichelemente}, pubstate = {published}, tppubtype = {inproceedings} } |
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J. Schumann, B. Schiebler, and F. Giovannetti Bewertung verschiedener Rückseitenreflektoren in stagnationssicheren Vakuumröhrenkollektoren Inproceedings Conexio. GmbH (Ed.): Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme, 449-465, Online Symposium, (2020). BibTeX | Tags: stagnationssicher @inproceedings{Schumann2020b,
title = {Bewertung verschiedener Rückseitenreflektoren in stagnationssicheren Vakuumröhrenkollektoren}, author = {J Schumann and B Schiebler and F Giovannetti}, editor = {Conexio GmbH}, year = {2020}, date = {2020-05-15}, booktitle = {Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme}, pages = {449-465}, address = {Online Symposium}, keywords = {stagnationssicher}, pubstate = {published}, tppubtype = {inproceedings} } |
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B. Schiebler, J. Schumann, F. Giovannetti, and S. Jack Experimentelle Bewertung von stagnationssicheren Flachkollektoren mit Wärmerohren zur solaren Trinkwarmwasserbereitung in Thermosiphonsystemen Inproceedings Conexio. GmbH (Ed.): Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme, 520-532, Online Symposium, (2020). BibTeX | Tags: stagnationssicher @inproceedings{Schiebler2020c,
title = {Experimentelle Bewertung von stagnationssicheren Flachkollektoren mit Wärmerohren zur solaren Trinkwarmwasserbereitung in Thermosiphonsystemen}, author = {B Schiebler and J Schumann and F Giovannetti and S Jack}, editor = {Conexio GmbH}, year = {2020}, date = {2020-05-15}, booktitle = {Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme}, pages = {520-532}, address = {Online Symposium}, keywords = {stagnationssicher}, pubstate = {published}, tppubtype = {inproceedings} } |
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P. Pärisch, C. Büttner, J. Keuler, B. Chhugani, and C. Lampe Warum sind Frischwasserstationen wichtig für die Dekarbonisierung großer Trinkwasserinstallationen? Inproceedings Conexio. GmbH (Ed.): Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme, 533-548, Online Symposium, (2020). BibTeX | Tags: Frischwasserstation @inproceedings{Pärisch2020d,
title = {Warum sind Frischwasserstationen wichtig für die Dekarbonisierung großer Trinkwasserinstallationen?}, author = {P Pärisch and C Büttner and J Keuler and B Chhugani and C Lampe}, editor = {Conexio GmbH}, year = {2020}, date = {2020-05-15}, booktitle = {Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme}, pages = {533-548}, address = {Online Symposium}, keywords = {Frischwasserstation}, pubstate = {published}, tppubtype = {inproceedings} } |
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O. Mercker, D. Büchner, and P. Pärisch Einzelraumfeuerstätten als vernachlässigte Option zur Strom- und/oder Gasnetzstabilisierung Inproceedings Conexio. GmbH (Ed.): Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme, 549-550, Online Symposium, (2020). BibTeX | Tags: Netzstabilisierung @inproceedings{Mercker2020c,
title = {Einzelraumfeuerstätten als vernachlässigte Option zur Strom- und/oder Gasnetzstabilisierung}, author = {O Mercker and D Büchner and P Pärisch}, editor = {Conexio GmbH}, year = {2020}, date = {2020-05-15}, booktitle = {Tagungsunterlagen 30. Symposium Solarthermie und Innovative Wärmesysteme}, pages = {549-550}, address = {Online Symposium}, keywords = {Netzstabilisierung}, pubstate = {published}, tppubtype = {inproceedings} } |
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T. Ohrdes WPuQ – Wind-Solar-Wärmepumpen-Quartier Presentation/Poster Online Meeting, 15.05.2020, (8. Projektleitertreffen Energiewendebauen). @misc{Ohrdes2020c,
title = {WPuQ – Wind-Solar-Wärmepumpen-Quartier}, author = {T Ohrdes}, year = {2020}, date = {2020-05-15}, address = {Online Meeting}, note = {8. Projektleitertreffen Energiewendebauen}, keywords = {Projekt}, pubstate = {published}, tppubtype = {presentation} } |
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S. Helmling, and P. Pärisch Initiative zur Marktetablierung und Verbreitung von Anlagen zur thermisch-elektrischen Energieversorgung mittels PVT-Kollektoren und Wärmepumpen im Gebäudesektor – integraTE Presentation/Poster Online Symposium, 14.05.2020, (30. Symposium Solarthermie und Innovative Wärmesysteme). @misc{Helmling2020,
title = {Initiative zur Marktetablierung und Verbreitung von Anlagen zur thermisch-elektrischen Energieversorgung mittels PVT-Kollektoren und Wärmepumpen im Gebäudesektor – integraTE}, author = {S Helmling and P Pärisch}, year = {2020}, date = {2020-05-14}, address = {Online Symposium}, note = {30. Symposium Solarthermie und Innovative Wärmesysteme}, keywords = {PVT}, pubstate = {published}, tppubtype = {presentation} } |
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F. Weiland Solare Stahl-Sandwichelemente im Industrie- und Gewerbebau: Systemsimulationen zur Potentialanalyse Presentation/Poster Online Symposium, 14.05.2020, (30. Symposium Solarthermie und Innovative Wärmesysteme). BibTeX | Tags: Stahl-Sandwichelemente @misc{Weiland2020,
title = {Solare Stahl-Sandwichelemente im Industrie- und Gewerbebau: Systemsimulationen zur Potentialanalyse}, author = {F Weiland}, year = {2020}, date = {2020-05-14}, address = {Online Symposium}, note = {30. Symposium Solarthermie und Innovative Wärmesysteme}, keywords = {Stahl-Sandwichelemente}, pubstate = {published}, tppubtype = {presentation} } |