@article{Keuler2024,

title = {Evaluation of thermal comfort during showering with system-related temperature fluctuations},

author = {J Keuler and K Albrecht and P Pärisch},

doi = {10.1016/j.jobe.2024.109162},

issn = {2352-7102},

year  = {2024},

date = {2024-07-01},

urldate = {2024-01-01},

journal = {Journal of Building Engineering},

volume = {88},

pages = {109162},

abstract = {With the decarbonization of heating sector with temperature-sensitive heat pump, comfort must be considered. For users, comfort is a decisive criterion that can hinder the decision for a supply system using renewable energies. Instantaneous domestic hot water heater pose a particular challenge here, as load changes can easily lead to temperature fluctuations. Therefore, the following study aims to determine the perception of temperature fluctuations during showering and to classify them for an assessment procedure. For this purpose, we carried out tests with 120 persons in a controlled environment. The test subjects showered at their desired temperature and gave direct feedback on imposed temperature fluctuations. Positive and negative changes with different rates of change were examined. We reported clear individual differences in the set desired temperatures as well as in the noticed and tolerated temperature fluctuations. The average desired temperature was 38.5 °C, with a quite large variation of ±5.5 K. While 2 % of the test subjects already noticed fluctuations <0.5 K and found them uncomfortable, for others (≈40 %) deviations of 4 K were still comfortable. Therefore, the resulting evaluation was based on a proportion of dissatisfied subjects according to the procedure described by the ISO 7730. This study represents a first step towards the introduction of standardized assessment of instantaneous water heaters and the comfort criteria would allow a comparison of control quality for different applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@article{Min2024,

title = {Wet-Chemically Grown Interfacial Oxide for Passivating Contacts Fabricated With an Industrial Inline Processing System},

author = {B Min and P Noack and B Wattenberg and T Dippell and H Schulte-Huxel and R Peibst and R Brendel},

doi = {10.1109/JPHOTOV.2024.3352836},

year  = {2024},

date = {2024-03-01},

urldate = {2024-01-22},

journal = {IEEE Journal of Photovoltaics},

volume = {14},

issue = {2},

pages = {233-239},

abstract = {This article presents for the first time the application of wet-chemical interfacial oxide from an industrial inline processing system for poly-Si-based passivating contacts. An excellent passivation quality is achieved by creating an interfacial oxide with a very short exposure time of 90 s in ozonized water and by adjusting the annealing temperature in a tube furnace, resulting in surface recombination current densities of 4 fA/cm 2 and 1.2 fA/cm 2 before and after a hydrogenation step, respectively. Detailed electrical characterization reveals the interplay of in-diffusion of P into the wafer and hydrogenation step. Our investigation shows that the optimum annealing temperature can differ before and after the hydrogenation step. The developed wet-chemical interfacial oxide is successfully implemented in back junction solar cells on large-area gallium-doped p-type silicon wafers (156.75 × 156.75 mm 2 ) featuring a phosphorus-doped poly-Si-based passivating contact at the rear side. The best cell has an efficiency of 23.6% and an open-circuit voltage of 719 mV, independently confirmed by ISFH CalTeC in Germany. Our cost calculation shows a saving of up to 17.2% in capital expenditure, 5.2% p.a. in operating expense, and 9.0% in the footprint if the interfacial oxide is formed by an inline wet-chemical processing system instead of a plasma chamber.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Mertens2024,

title = {Plasma enhanced chemical vapor-deposited SiOx(Ny)/n-type polysilicon on oxide passivating contacts in industrial back-contacted Si solar cells},

author = {V Mertens and S Dorn and J Langlois and M Stöhr and Y Larionova and W Veurman and R Brendel and N Ambrosius and A Vogt and T Pernau and H Haverkamp and T Dullweber},

doi = {10.1002/solr.202300919},

year  = {2024},

date = {2024-01-29},

journal = {Solar RRL},

abstract = {In this paper we investigate different in situ grown Plasma Enhanced Chemical Vapor Deposition (PECVD) grown interfacial oxides for n-type polysilicon passivating contacts. We apply SiOx(Ny)/n-type amorphous silicon stacks created from either N2O plasma or O2 plasma to POLO IBC solar cells using our structured deposition process through a glass mask to create the IBC layout. We determine experimentally the impact of plasma exposure time for interfacial oxide growth on solar cell efficiencies. The POLO IBC cell results show that the PECVD oxides SiOxNy and SiOx with optimized plasma exposure time give similar maximum efficiencies of 23.8 % and 23.7 %, respectively. These data demonstrate the feasibility to deposit a high-quality in situ PECVD interfacial SiOx(Ny) layers for surface passivation and current transport of passivated contacts at the same time. For the SiOx/n-type polysilicon stack we find that both, plasma exposure time for interfacial oxide growth or polysilicon anneal temperature variations, can lead to similar optimum of solar cell efficiencies. We analyze the current Voc losses due to metallization for our solar cells and calculate a realistic to achieve efficiency of 25.22 % for an optimized POLO IBC solar cells applying the Synergistic Efficiency Gain Analysis (SEGA) on Quokka3 simulations. This article is protected by copyright. All rights reserved.},

keywords = {},

pubstate = {forthcoming},

tppubtype = {article}

}

@article{Green2024,

title = {Solar cell efficiency tables (Version 63)},

author = {M A Green and E D Dunlop and M Yoshita and N Kopidakis and K Bothe and G Siefer and X Hao},

doi = {10.1002/pip.3750},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Progress in Photovoltaics: Research and Applications},

volume = {32},

number = {1},

pages = {3-13},

abstract = {Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since July 2023 are reviewed.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Salomon2024,

title = {Assessment of the Required Maximum-Power-Point-Tracking Speed for Vehicle-Integrated Photovoltaics Based on Transient Irradiation Measurements and Dynamic Electrical Modeling},

author = {L Salomon and G Wetzel and J Krügener and R Peibst},

doi = {10.1002/solr.202300795},

year  = {2024},

date = {2024-01-01},

urldate = {2023-11-13},

journal = {Solar RRL},

volume = {8},

issue = {2},

pages = {2300795},

abstract = {Fast changing irradiation on vehicle-integrated photovoltaic (VIPV) modules may impose demanding requirements for maximum power point tracking (MPPT) to ensure high energy conversion efficiency. In this work, the results of simulations regarding the output and efficiency of an exemplary VIPV module under real-life irradiation conditions as measured with high time resolution are resulted. Herein, resistive as well as voltage source load is used as two idealized models of the MPPT. The simulations show that, in most cases, tracking with a resistive load at 1 Hz preserves above 90%rel of the convertible energy determined by the cell performances under given irradiance levels. With a voltage source load, these values do not undercut 97%rel at 0.1 Hz. Herein, it is also found that partial shading across the exemplary series connected module can reduce the converted energy in the range of 5–10%rel in relation to complete negligence of this effect.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Schulte-Huxel2024,

title = {Novel busbar design for screen-printed front side Al metallization of high-efficiency solar cell},

author = {H Schulte-Huxel and T Daschinger and B Min and T Brendemühl and R Brendel},

doi = {10.1016/j.solmat.2023.112601},

issn = {0927-0248},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Solar Energy Materials and Solar Cells},

volume = {264},

pages = {112601},

abstract = {The need to reduce the silver consumption for future global PV production requires novel approaches for cell metallization and module integration. A screen-printed aluminum cell metallization on the front side could contribute here, but requires a redesign of the solder pads and busbars. A compromise between shading and resistive losses is needed. We investigate the inclusion of Ag solder pads in high-aspect-ratio Al finger grids on the front side of p-type back junction solar cells featuring passivating polysilicon on oxide (POLO) contacts on the rear side. In order to determine the optimal geometric dimensions of the solder pads, we characterize the resistance at the interface between the Ag solder pads and the Al finger grid in dependence on the size of the overlap between the two paste. A contact resistance of 285 mΩ is determined for 200 μm-narrow Al busbars and small solder pads of 750 μm in length. This would require tens of solder pads per busbar for acceptable power losses below 0.5 % coming along with significant shading. Therefore, a new metallization design is developed. We use narrow Ag busbars with a widened intersection to the Al fingers in order to reduce the contact resistance caused by the Ag–Al alloy. Thereby, the shading losses of the solderable busbars and pads are less than 1.5 %.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Herz2023,

title = {Identify, analyse and mitigate—Quantification of technical risks in PV power systems},

author = {M Herz and G Friesen and U Jahn and M Koentges and S Lindig and D Moser},

doi = {10.1002/pip.3633},

year  = {2023},

date = {2023-12-01},

urldate = {2023-01-01},

journal = {Progress in Photovoltaics: Research and Applications},

volume = {31},

number = {12},

pages = {1285-1298},

abstract = {Technical risks are important criteria to consider when investing in new and existing PV installations. Quantitative knowledge of these risks is one of the key factors for the different stakeholders, such as asset managers, banks or project developers, to make reliable business decisions before and during the operation of their PV assets. Within the IEA PVPS Task 13 Expert Group, we aim to increase the knowledge on methodologies to assess technical risks and mitigation measures in terms of economic impact and effectiveness. The developed outline provides a reproducible and transparent technique to manage the complexity of risk analysis and processing in order to establish a common practice for professional risk assessment. Semi-quantitative and quantitative methodologies are introduced to assess technical risks in PV power systems and provide examples of common technical risks described and rated in the new created PV failure fact sheets (PVFS). Besides the PVFS based on expert knowledge and expert opinion, an update on the statistics of the PV failure degradation survey is given. With the knowledge acquired and data collected, the risk and cost–benefit analysis is demonstrated in a case study that shows methods for prioritising decisions from an economic perspective and provided important results for risk managing strategies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Tous2023,

title = {Overview of key results achieved in H2020 HighLite project helping to raise the EU PV industries' competitiveness},

author = {Loic Tous and Jonathan Govaert and Samuel Harrison and Carolyn Carrière and Vincent Barth and Valentin Giglia and Florian Buchholz and Ning Chen and Andreas Halm and Antonin Faes and Gizem Nogay and Hugo Quest and Torsten Roessler and Tobias Fellmeth and Dirk Reinwand and Hannah Stolzenburg and Florian Schindler and Max Mittag and Arnaud Morlier and Matevz Bokalic and Kristijan Brecl and Miha Kikelj and Marko Topic and Josco Kester and Stefan Wendlandt and Marco Galiazzo and Alessandro Voltan and Giuseppe Galbiati and Marc Estruga Ortiga and Frank Torregrosa and Michael Grimm and Julius Denafas and Tadas Radavicius and Povilas Lukinskas and Tuukka Savisalo and Thomas Regrettier and Ivan Gordon},

doi = {10.1002/pip.3667},

year  = {2023},

date = {2023-12-01},

urldate = {2023-01-12},

journal = {Progress in Photovoltaics: Research and Applications},

volume = {31},

issue = {12},

pages = {1409-1427},

abstract = {The EU crystalline silicon (c-Si) PV manufacturing industry has faced strong foreign competition in the last decade. To strive in this competitive environment and differentiate itself from the competition, the EU c-Si PV manufacturing industry needs to (1) focus on highly performing c-Si PV technologies, (2) include sustainability by design, and (3) develop differentiated PV module designs for a broad range of PV applications to tap into rapidly growing existing and new markets. This is precisely the aim of the 3.5 years long H2020 funded HighLite project, which started in October 2019 under the work program LC-SC3-RES-15-2019: Increase the competitiveness of the EU PV manufacturing industry. To achieve this goal, the HighLite project focuses on bringing two advanced PV module designs and the related manufacturing solutions to higher technology readiness levels (TRL). The first module design aims to combine the benefits of n-type silicon heterojunction (SHJ) cells (high efficiency and bifaciality potential, improved sustainability, rapidly growing supply chain in the EU) with the ones of shingle assembly (higher packing density, improved modularity, and excellent aesthetics). The second module design is based on the assembly of low-cost industrial interdigitated back-contact (IBC) cells cut in half or smaller, which is interesting to improve module efficiencies and increase modularity (key for application in buildings, vehicles, etc.). This contribution provides an overview of the key results achieved so far by the HighLite project partners and discusses their relevance to help raise the EU PV industries' competitiveness. We report on promising high-efficiency industrial cell results (24.1% SHJ cell with a shingle layout and 23.9% IBC cell with passivated contacts), novel approaches for high-throughput laser cutting and edge re-passivation, module designs for BAPV, BIPV, and VIPV applications passing extended testing, and first 1-year outdoor monitoring results compared with benchmark products.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Schulte-Huxel2022c,

title = {Optimal interconnection of three-terminal tandem solar cells},

author = {H Schulte-Huxel and R Witteck and S Blankemeyer and M Köntges},

doi = {10.1002/pip.3643},

year  = {2023},

date = {2023-12-01},

urldate = {2022-11-13},

journal = {Progress in Photovoltaics: Research and Applications},

volume = {31},

issue = {12},

pages = {1350-1359},

abstract = {Three-terminal (3T) tandem solar cells require an adapted module integration scheme in order to explore their full efficiency potential. The three terminals allow to extract the power of the top and bottom cell separately. In a cell string, the wide bandgap top cells are interconnected in parallel to multiple bottom cells resulting in a parallel/series interconnection. This interconnection scheme affects the operation of the subcells, the resulting current path between the subcells, the layout of the cell interconnects, and the system level. Here, we analyze by simulations and experiments the aspects of the module integration of series- and reverse-connected 3T cells with their practical impact on module processes and performance as well as the effect of varying voltage ratios on the string-end losses. If the subcells are connected in series, the module integration requires insulation layers and significantly longer interconnects compared to devices with reverse-connected subcells. Tandem devices with a reverse connection and a voltage ratio between top and bottom cell of 2:1 allow a lean interconnection design and low integration losses. We present an approach for the integration of bypass diodes for the protection against shading effects that allow to minimize string-end and shading losses for a system of modules featuring 3T cells.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}