Progress in Photovoltaics最新文献

We assess the accuracy of two steady-state temperature models, namely, Ross and Faiman, in the context of photovoltaics (PV) systems integrated in vehicles. Therefore, we present an analysis of irradiance and temperature data monitored on a PV system on top of a vehicle. Next, we have modeled PV cell temperatures in this PV system, representing onboard vehicle PV systems using the Ross and Faiman model. These models could predict temperatures with a coefficient of determination (R²) in the range of 0.61–0.88 for the Ross model and 0.63–0.93 for the Faiman model. It was observed that the Ross and Faiman model have high errors when instantaneous data are used but become more accurate when averaged to timesteps of greater than 1000–1500 s. The Faiman model's instantaneous response was independent of the variations in the weather conditions, especially wind speed, due to a lack of thermal capacitance term in the model. This study found that the power and energy yield calculations were minimally affected by the errors in temperature predictions. However, a transient model, which includes the thermal mass of the vehicle and PV modules, is necessary for an accurate instantaneous temperature prediction of PV modules in vehicle-integrated (VIPV) applications.

Levelized cost of electricity (LCOE) is a crucial metric for assessing the socio-economic cost-efficiency potential of various energy sources including solar photovoltaics. Nevertheless, accurate LCOE estimations for commercialized high-efficiency Si solar modules with passivated emitter and rear cell (PERC) and silicon heterojunction (SHJ) structures have been lacking. In this study, we present the first global LCOE estimates for a PERC module (20% cell efficiency) and a SHJ module (23% cell efficiency), which have been derived by (i) performing rigorous energy-yield calculations with full-spectral and temperature-dependent simulations that incorporate all essential meteorological effects and (ii) considering country-specific capital costs and discount rates. Moreover, to determine the universal global LCOE, the LCOEs for three distinct installation capacities (100 MW for a utility, 500 kW for a commercial, and 5 kW for a residential system) have been unified by selecting an appropriate system size at each location based on a population density. We find that the LCOEs of both PERC and SHJ systems are below 3 cents/kWh in 2020 US dollar in many areas of China, Saudi Arabia, the United States, Australia, Chile, and Botswana, where the conditions of a high energy yield, low population density, low capital cost, and low country-risk premium are satisfied simultaneously. In contrast, many European countries exhibit a moderate LCOE of 3~5 cents/kWh. Notably, Japan and Russia exhibit quite high LCOEs (6~10 cents/kWh) primarily due to significantly higher installation costs and moderate energy yields. Importantly, the global LCOEs of the PERC and SHJ modules are quite similar, with the SHJ module showing a slightly better cost performance in the regions near the equator due to its low temperature coefficient. Conversely, the PERC module demonstrates a cost advantage in the Northern Hemisphere due to a lower module cost.

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 January 2024 are reviewed.

Solar electricity is set to play a pivotal role in future energy systems. In view of a market that may soon reach the terawatt (TW) scale, a careful assessment of the performance of photovoltaic (PV) systems becomes critical. Research on PV fault detection and diagnosis (FDD) focuses on the automated identification of faults within PV systems through production data, and long-term performance evaluations aim to determine the performance loss rate (PLR). However, these two approaches are often handled separately, resulting in a notable gap in the field of reliability. Within PV system faults, one can distinguish between permanent, irreversible effects (e.g. bypass diode breakage, delamination and cell cracks) and transient, reversible losses (e.g. shading, snow and soiling). Reversible faults can significantly impact (and bias) PLR estimates, leading to wrong judgements about system or component performance and misallocation of responsibilities in legal claims. In this work, the PLR is evaluated by applying a fault detection procedure that allows the filtering of shading, snow and downtime. Compared with standard filtering methods, the addition of an integrated FDD analysis within PLR pipelines offers a solution to avoid the influence of reversible effects, enabling the determination of what we call the intrinsic PLR (i-PLR). Applying this method to a fleet of PV systems in the built environment reveals four main PLR bias scenarios resulting from shading losses. For instance, a system with increasing shading over time exhibits a PLR of −1.7%/year, which is reduced to −0.3%/year when reversible losses are filtered out.

An aluminum oxide (AlO_x)/silicon nitride (SiN_y) dielectric stack was developed using an industrial plasma-enhanced chemical vapor deposition (PECVD) system with low-frequency (LF) plasma source for the surface passivation of undiffused textured p-type crystalline silicon. The median recombination current density is 4.3 fA cm⁻² as determined from photoconductance decay lifetime measurements and numerical device modeling. To the best of our knowledge, this is the first time to present a high-quality LF-PECVD AlO_x/SiN_y passivation stack on undiffused textured p-type crystalline silicon wafers, which are cleaned with industrial processes using HF, HCl, and O₃. The simulation agrees well with the measured effective carrier lifetime if the velocity parameters of 5.6 cm s⁻¹ for holes and 803 cm s⁻¹ for electrons are applied with a fixed negative charge density of −3 × 10¹² cm⁻². The process integration of developed AlO_x/SiN_y dielectric stack is successfully demonstrated by fabricating p-type back junction solar cells featuring a poly-Si-based passivating contact at the cell rear side. As the best cell efficiency, we achieve 24.2% with an open-circuit voltage of 725 mV on a M2-sized Ga-doped p-type Czochralski-grown Si wafer as independently confirmed by ISFH CalTeC.

Desert regions have emerged as ideal places for GW utility-scale photovoltaic (PV) module installations because of their ultra-large spaces, abundance of high-irradiance sunshine hours, and clear sky. However, the harsh desert climate presents challenges to the reliability and bankability of PV modules. This review provides an in-depth understanding of the unique desert parameters impact, desert-induced degradation modes, status, and required properties of the bill of materials (BOMs) and suggestions for the development of desert standards. The review reveals that the climatic conditions in the desert are considerably harsher than those in the moderate climate. The main degradation mechanisms caused by the desert are ultraviolet (UV)-induced discoloration, thermomechanical flaws of interconnects, and glass abrasion (because of soiling). The development of desert modules may necessitate the use of new-generation modules with low-temperature coefficients, high efficiency, high bifaciality, stability under UV light, and elevated temperatures. For the desert module application, options include advanced back sheets and encapsulants that are thermally and UV stable, free of acetic acid groups, and have a low water vapor transfer rate. The degradation modes induced by desert climate are not sufficiently addressed by the present environmental and safety standards through accelerated aging tests. As a result, this article provides a summary of current standards and recommends creating a new testing proposal called the “Hot Desert Test Cycle (HDTC)” sequence that is specific to the desert climate. This comprehensive review catalyzes the PV community to explore novel designs and develop desert PV modules while adhering to localized standards.

Modeling of solar modules and their components is essential to quantify geometrical, optical, and electrical losses and to improve the designs and technologies in terms of performance. In most loss analysis models, the current share among the busbars of the solar cell is assumed to be equal since a symmetrical distribution of the metallization is given. The impact of string terminal connection on the current distribution among the ribbons and the resulting changes in ohmic losses has not been studied yet. In this study, a MATLAB model is developed to consider the impact of the string connector terminal position on the current distribution and the ohmic losses in the ribbons and in string connector. The model allows for the analysis of the impact of contact defects scenarios in ribbons and string connectors on the current distribution. Results show that the highest current flows at the closest busbar to the string connector terminal while the current decreases at the busbars farther away from the terminal due to higher ohmic resistance of the current path. The higher the ohmic resistance of the string connector, the more inhomogeneous the current share at busbars. Simulating a 9 busbar M6 half-cell with 1 × 0.08 mm² string connector, positioning the string connector terminal at the leftmost or rightmost ribbon results in 0.4 W less power compared to center connection configuration, where the string connector terminal is positioned at the center ribbon. Furthermore, simulation results show that inhomogeneity of current causes about 2.1% reduction in module power compared to the case of evenly distributed cell current, considering a 120-haf-cell module with the same string connector. Regarding contact defect analysis, exemplary simulations show the impact of the position of detached ribbons on the power or efficiency loss. Considering left or right connection configuration, detaching the leftmost or rightmost ribbon results in higher power loss compared to other ribbons. Detaching one cell ribbon completely from the string connector results in about 0.2%_abs decrease in cell efficiency, while detaching the outer ribbon along all strings of a 120-half-cell module results in power loss of about 0.8%. The developed model is validated by performing magnetic field imaging (MFI) measurements, in which the magnetic flux density induced by the current carried by the ribbons is measured.

This work presents a practical approach to designing an optical filter for thermal management for photovoltaic modules. The approach emphasizes the practicality of manufacturing over optical performance. Simulation work demonstrates that, for an interdigitated back contact solar cell architecture, complete rejection of infrared radiation offers limited thermal benefits requiring highly complex optical filter designs. An alternative approach consists of reducing thermalization losses by providing reflectance at lower wavelength values. An optical filter design that fulfills this requirement is possible using simple structures based on two materials and taking advantage of the harmonics present in quarter wavelength optical thickness designs. The filter is later optimized for angular performance via second-order algorithms, resulting in a device consisting of only 15 thin-film layers. Performance simulations on two locations, Delft (the Netherlands) and Singapore, estimate a temperature reduction of 2.20°C and 2.45°C, respectively. In a single year, the optical loss produced by the filter is not compensated via temperature reduction. However, improvements in the annual degradation rate show that in Singapore, the overall effect of the filter on the lifetime DC energy yield is positive.

The manuscript is a digest, which puts forward findings from previous research papers, combined with new proposals. Approaches comprise two full models' derivation for photovoltaic (PV) systems energy conversion predictability. It brings in several models for key physical observables formulated as functions of the operating conditions. The proposals encompass mean spectral reflectance, coefficient for reflections and spatial geometry, incident angular losses factor, angular losses, and fill factor along with its coefficient of temperature. Applying the superposition principle, these models are integrated into two full approaches for performance predictability. The underlying physics description is mathematically consistent with experimental measurements of the physical observables involved, reported in other studies. To the authors' knowledge, these full models have been reported previously nowhere. Simulation results from the more inaccurate of two full models show good agreement of these findings with the experimental evidence, reported of its performance. The resulting key performance indicators (KPIs), after simulating a grid-connected PV system located in Cuba, yield 1.61%, 13.10%, −1.61%, 2.02%, and 0.81 of MAE, MAPE, MBE, RMSE, and R², respectively, which they confirm the model's good behavior. Approaches formulations, as functions of solar irradiance and module temperature, its derivations, applications, and model's simulation results are considered the main manuscript novelties.

Integration of photovoltaics (PV) into the built environment (BIPV) and infrastructure (IIPV) is required to increase the installed capacity of PV worldwide, while still leaving sufficient area for other land uses. Although BIPV applications have proven to play a significant role in the energy transition, road integrated IIPV concepts are less developed and bring challenges in mechanical and electrical stability and safety that still need to be addressed. In this work, the feasibility of integrating thin-film CIGS (Copper Indium Gallium Selenide) modules into road tiles is investigated. PV road stacks were produced by gluing CIGS laminates onto concrete tiles and covering them with epoxy and glass granulates to form impact- and anti-skid layers. IV (current–voltage) characteristics show that, respectively, a thin and thick epoxy layer results in 2% and 6.6% relative loss in power conversion efficiency. Although a thin protective layer would be beneficial to the power conversion efficiency of road modules, raveling tests show increased risk for electrical failure when a thin top layer is used. Pull-off tests showed that the weakest adhesive strength (0.8 N/mm²) is between the thin-film laminate and concrete, offering sufficient adhesive strength to at least withstand light traffic loading. Raveling and wheel tracking tests show no mass loss and only minor deformation of the stack, respectively, indicating no real risk of raveling or rutting. Thermal cycling and damp heat exposure of the PV road tiles show that yellowing of the top layers can significantly reduce performance over longer periods of outdoor operation. Damp heat exposure after mechanical loading shows no indication of moisture ingress on any of the tested configurations, suggesting the proposed CIGS laminate stack is able to withstand light traffic loading. From the measurement results, it can be concluded that thin-film CIGS modules are mechanically and electrically suitable for road integration. Power conversion efficiencies over 12% can be attained with this technology, indicating its potential for renewable energy generation in road infrastructure. Performance stability can especially benefit from alternative top layer materials that maintain high transparency over long lifetimes. Additionally, pilot tests are required to demonstrate the potential of the technology in a controlled outdoor environment.