1,721,106 research outputs found
Development and analysis of structural timber-glass façade systems with integrated photovoltaics
No full textThere is an increase in interest in timber as a material for the design of the load-bearing system of a building. At the same time, large glass façades are often desired in modern buildings. Additionally, the production of green energy is an increasingly important design principle for buildings. These three requirements can be combined in a structural timber-glass façade with integrated photovoltaics, which is the topic of this contribution. However, there is a lack of design rules for these systems. The timber-glass connection design is developed in this work to exploit the in-plane stiffness of the glass panel and increase the horizontal stability of the underlying timber structure. A detailed numerical model is validated with experimental tensile and shear tests on the connections. Additionally, the glass/glass photovoltaic elements are studied with a numerical model that predicts stresses and strains in the glass and the solar cells under various loading conditions. Experimental in-and out-of-plane bending tests are performed on glass/glass photovoltaic (PV) modules to validate the numerical results. With this combined numerical-experimental approach, reliable models are made that can be used for designing structural timber-glass façade elements with integrated photovoltaics
Ultrasonic bonding of aluminium ribbons to molybdenum back contacted CIGS modules
No full textThe connection of the output terminals of thin film photovoltaic (TFPV) modules with a molybdenum (Mo) back contact is challenging
because of the molybdenum diselenide (MoSe2) layer which is formed during the selenization process. MoSe2 is known to be highly resistive and previous research showed that high temperature soldering is not favourable for CIGS. In this work, we present the possibilities of ultrasonic bonding in order to create a low resistive and reliable connection of the output terminals
OPTICAL STRAIN AND TEMPERATURE SENSING WITHIN PHOTOVOLTAIC LAMINATES
No full textQuantifying the lifetime of photovoltaic modules is getting increasingly important with the aim to drive further technological developments, to reduce financial risks and to accelerate the deployment for new photovoltaic applications. Many lifetime limiting factors can be directly or indirect related to temperature and strain acting on the laminate constituents. In this work a novel optical sensing solution is proposed based on Fibre Bragg Grating sensors which enables a direct validation of the thermo-mechanical strain within a PV laminate. A combined sensor package enables a direct monitoring or validation of the thermo-mechanical stress of a PV cell during production, accelerated testing and field testing. Initial testing shows a high potential due to the non-invasive nature, high sensitivity, scalability and optical transparency
Temperature Cycling Test on Ultrasonic Aluminum Bonds and Conductive Adhesive of Copper Indium Gallium (di)Selenide (CIGS) Thin-Film Photovoltaic Solar Panel
No full textThis work assesses the bondability and temperature cycling reliability of ultrasonic Al bonds on Molybdenum (Mo) and Molybdenum (di)Selenide (MoSe2) layers of a Copper Indium Gallium (di)Selenide (CIGS) thin-film photovoltaic (TFPV) solar panel. The bondability and reliability of ultrasonic Al bonds were assessed using a qualitative load-displacement profile and quantitative peel force data obtained from a peel test, as well as contact resistance R-c measured using the transmission line method. It was discovered that using the peel test to examine the bondability and reliability of ultrasonic Al bonds and conductive adhesives was quite beneficial. Varied forms of ultrasonic Al bonds and conductive adhesives, either on Mo or MoSe2 layers, have different shapes of load-displacement profiles before and after the application of temperature cycling. Therefore, comparing the load-displacement profile, peel force, and R-c could offer a complete bonding mechanism, failure modes, and failure mechanism for ultrasonic Al bond on MoSe2 and Mo layers of CIGS TFPV solar panels before and after temperature cycling.Ministry of Higher Education of Malaysia
Fundamental Research Grant Scheme (Grant Number: FRGS/1/2020/TKO/UNIKL/02/10)
10.13039/501100009848-Universiti Kuala Lumpur (Grant Number: str19087
Ultrasonic bonding of aluminium ribbons to molybdenum back contacted CIGS modules
No full textThe connection of the output terminals of thin film photovoltaic (TFPV) modules with a molybdenum (Mo) back contact is challenging
because of the molybdenum diselenide (MoSe2) layer which is formed during the selenization process. MoSe2 is known to be highly resistive and previous research showed that high temperature soldering is not favourable for CIGS. In this work, we present the possibilities of ultrasonic bonding in order to create a low resistive and reliable connection of the output terminals
Effect of ultrasonic bonding and lamination on electrical performance of copper indium gallium (de)Selenide CIGS thin film photovoltaic solar panel
No full textThis paper aims to study the effect of ultrasonic aluminum (Al) bonding and lamination processes on the electrical performance of copper indium gallium (di)selenide (CIGS) thin film photovoltaic (TFPV) solar panels. Ultrasonic Al bonding on the MoSe2 layer of the CIGS TFPV solar panel was performed in three configurations: eight bonds, 16 bonds, and parallel configurations. The lamination process was performed on the Al bonds with MoSe2 layers of the CIGS TFPV solar panel. Ultrasonic bonding and lamination processes significantly affect the electrical performance of CIGS TFPV solar panels. Open circuit voltage, Voc is the least affected electrical characteristic with the application of ultrasonic bonding and lamination processes as compared to short circuit current (Isc), current density (Jsc), maximum power (Pmpp), fill factor (FF), and efficiency. 8-bonds configuration has the highest efficiency, ranging from 11.45% to 13.86% throughout unique connections of I-V measurement, compared to 16-bonds ranging from 7.99% to 10.77%, and parallel configurations, ranging from 9.14% to 11.92%. The notable variations in electrical properties with the processes used to create laminated CIGS TPFV solar panels with ultrasonic Al bonding can be explained by physical examination and lock-in infrared (IR) thermography. The ultrasonic Al bond is best suited to be used as the interconnection mean in the CIGS TFPV solar panel compared to that of conductive adhesive that has been widely applied nowadays.This work was sponsored by the Ministry of Higher Education of Malaysia under the Fundamental Research Grant Scheme [FRGS/1/2020/TKO/UNIKL/02/10] and Universiti Kuala Lumpur under Short Term Research Grant [str19087]
Real-time temperature sensitive electrical parameters and model- based condition monitoring for PV inverter applications
No full textTo improve the reliability of power converters, condition monitoring is a useful approach as this allows
to schedule maintenance more carefully or even implement adaptive control. The current state of the
art is focused on the measurement of damage sensitive parameters which can be used directly or
complementary with a digital twin. Several papers report successful experiments where these damage
sensitive parameters of switching devices are used to evaluate wear under constant power conditions.
This approach needs to be extended for PV inverter applications as these experience complex power
profiles in varying weather conditions. This poster presentation will focus on a methodology to monitor
the damage sensitive drain to source on-resistance in concession with the internal gate resistance which
is only sensitive to the junction temperature. This allows to separate the influence of temperature and
damage which allows the use of complex mission profiles. To simplify the evaluation even further, a
second approach is proposed where the additional gate resistance measurement is replaced by a
modeling strategy. The electrical part of the electro-thermal model is build using a two dimensional
lookup table approach and the thermal model is represented by a Cauer network. The thermal
resistances in each layer are determined by a FEM simulation. This poster presents the preliminary
results which show a validation of the model with measurements on an inverter prototype and the
proposed condition monitoring circuits simulated in spice
Real-Time MOSFET Condition Monitoring for Variable Mission Profiles With a Dual Extended Kalman Filter
No full textThe article proposes a methodology to detect real-time power mosfet degradation, in variable mission profile applications, using externally measurable electrical parameters. This complements the work done for fixed operation conditions in current literature. To achieve this, the damage and temperature sensitive drain to source resistance is accompanied with a gate resistance measurement only sensitive to temperature. Together, they allow for the detection of, and the distinction between, bond wire and die attach solder layer degradation. A dual extended Kalman filter is used to filter the measurement data and to estimate the change in thermal model. The article shows the measurement circuits together with proof of concept lab results in a solar photovoltaic use case. The main aim is to show that the resistance measurement can be compensated for mission profile temperature variations and that the thermal resistance can be estimated, reflecting bond wire and die attach solder layer degradation.Flanders Innovation & Entrepreneurship and Flux50 under project DAPPE
On The Susceptibility of PID in Perovskite Modules: A Comparison of ITO and Cu Contacts
No full textOrganic-inorganic perovskite lead halide solar cells (PSCs) have received increasing interest in the last decade. PSCs already achieve record efficiencies above 25%. However, long-term stability is still a problem, especially when transitioning from cells to modules.
One of the described long-term stability problems at the module level is Potential-induced degradation (PID), caused by the voltage build-up by modules connected in series.
PID is extensively investigated within crystalline silicon PV, while very little is known for perovskites. Carolus et al. reported nearly complete efficiency losses within 18 hours of a PID stress test, indicating their high susceptibility to PID[1]. In order to tackle PID-related stability issues and make commercialization a reality, it is crucial to retrieve insights into the physics of the PID mechanism.
This study investigates and compares the PID mechanism within p-i-n CsFAPbIBr perovskite modules with either a copper (Cu) or an indium tin oxide (ITO) rear contact. Several soda-lime glass-glass configured 5.5 x 5.5 cm² mini-modules were PID stressed from the p-side at 40⁰C and 1000 V for 192 hours using the foil method. Intermediate current-voltage measurements (IV) and electroluminescence (EL) images were taken to investigate the PID progress.
The ITO contacted perovskite modules illustrate an incubation period of about 100 hours. A slight drop in short-circuit current (Isc) and a modest increase in series resistance can be observed within this incubation period.
Subsequently, a significant drop in Isc and increase in series resistance are noticeable. Evidently, after 192 hours, an additional decrease in shunt resistance is noticeable, resulting in a total relative loss of efficiency of almost 80%. The EL images illustrate no significant differences in the incubation period, although the formation of inhomogeneities can be observed further in the degradation process[2].
The Cu-contacted perovskite modules are significantly more prone to PID than their ITO counterpart. Similarly, the drop in Isc and increase in series resistance can be observed; however, no incubation period is present.
Analogous to crystalline silicon, it is hypothesized that positively charged sodium ions migrate out of the cover glass towards the PV cell. Hence, the ions can alter the conductivity of the contacts or migrate deeper into the stack and form inhomogeneities in the perovskite material[3]. However, additional PID stress tests are ongoing to validate the hypothesized findings. Furthermore, microstructural analysis is necessary to designate this degradation mechanism's root cause and retrieve more insights into its physical behavior and kinetics
PET-based perovskite solar cells to avoid potential-induced degradation
No full textInterest in perovskite solar cells (PSCs) has grown, with advances in stability and scalability for commercialization. However, in real-world conditions, PSCs can encounter potential-induced degradation (PID), primarily due to sodium ion (Na+) migration from conventional soda-lime glass (SLG) substrates. This study investigates whether PID can be completely avoided using Na+-free substrates such as polyethylene terephthalate (PET). PET and SLG-based PSCs were subjected to -1000 V PID stress. The test was conducted in an inert environment to exclude other degradation factors. After 300 h, PET-based PSCs demonstrated only a 0.11% efficiency loss, staying well below the 5% stability threshold, compared to a 15% loss in SLG-based PSCs. The results confirm that using Na+-free substrates effectively prevents PID, and that Na+ migration is the primary cause of degradation during PID stress. These findings support further research to develop PID-resistant PSCs.This work was supported by “Fonds Wetenschappelijk Onderzoek” and the FWO SB PhD fellowship funding under Project No. 1SD8323N. Furthermore, the authors would like to sincerely thank Shanti Van Malderen for her contributions and insightful guidance throughout this research
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