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This study investigates the impact of degradation in perovskite‐silicon tandem solar cells by means of energy yield (EY) modelling over the entire lifetime. First, we assess the impact on EY of degradation in the individual solar cell parameters of the perovskite top cell. Our analysis reveals that degradation in fill factor, due to a decline in perovskite top cell shunt resistance (RSh), has the most severe impact on the EY, emphasizing the imperative to rectify perovskite imperfections in thin film processing causing RSh decline. Second, we investigate implications of degradation in the perovskite top cell on the EY of current mismatched tandem solar cells. Third, we examine critical thresholds for the "acceptable degradation levels" in the perovskite top cell with regard to degradation in each solar cell parameter, assuming that the total loss in EY must be comparable to the degradation in state‐of‐the‐art silicon. Overall, our study highlights that degradation of the perovskite top cell needs to be assessed with care when extrapolating the impact on the lifetime EY of perovskite‐silicon tandem solar cells. The severity of degradation for different degradation mechanisms in a single junction perovskite solar cell cannot be translated one‐to‐one to tandem devices. [ABSTRACT FROM AUTHOR]

We provide a comprehensive analysis of the effect of spectral albedo on photovoltaic (PV) module measurements and system model predictions. We demonstrate how to account for albedo in indoor bifacial device measurements by adjusting the applied irradiance using the scaled rear irradiance method, exemplified on fabricated silicon heterojunction (SHJ) modules. System model performance is studied using a detailed 3D finite‐element model, DUET, for fixed‐tilt and horizontal single‐axis tracked (SAT) arrays between 15 and 75°N. Spectral effects cause variations in measured SHJ module short‐circuit current up to 2% and efficiency variation up to 0.3% abs. We further demonstrate that rear‐side spectral mismatch factors (SMMs) resulting from including or omitting spectral albedo in PV system modeling vary between ±13%, while total (front+rear) SMMs vary up to 3%, depending on the deployment configuration and latitude. SAT array SMMs are weakly correlated with latitude, while fixed‐tilt array SMMs increase with latitude, driven by an increasing proportion of ground‐reflected light on the front‐side of modules. Ground‐reflections can constitute between 2% and 32% of total incident module irradiance, with notably high (>10%) contributions for fixed‐tilt arrays at high latitude. Effects of spectral albedo are most significant for: (1) fixed‐tilt deployments at high latitudes, (2) wide bandgap technologies such as perovskite and cadmium telluride cells, (3) albedos which vary steeply over the technology's absorption range, and (4) high albedo ground covers. Overall, we demonstrate that omitting spectral albedo effects can result in PV measurement and system‐level modeling uncertainties on the order of several percent in these cases. [ABSTRACT FROM AUTHOR]

This research explores the potential of electric field enforcement in dielectric barrier discharge using specially designed pyramid‐shaped μ‐electrodes for a plasma‐assisted nitrogen fixation process. The obtained results are compared under varying conditions, including the presence and absence of titanium dioxide (TiO2 ${TiO_2 }$), different oxygen concentrations in the nitrogen‐feeding gas, and residence time. The results demonstrate that the μ‐electrodes lead to an enhancement of nitrogen oxidation, which is further intensified by TiO2 ${TiO_2 }$. The introduction of 60–70 % oxygen with nitrogen achieves the highest level of NOX ${NO_X }$ production. The synergistic effect of plasma and the catalytic effect of TiO2 ${TiO_2 }$ increase the rate of NOX ${NO_X }$ production by 20 %, resulting in a 23 % increase in energy yield. The introduction of TiO2 ${TiO_2 }$ leads to a sharp increase in NOX ${NO_X }$ production even at lower oxygen concentrations. The crucial role played by ultraviolet light‐induced electron‐hole pairs in TiO2 ${TiO_2 }$ is highlighted to promote nitrogen oxidation. Nevertheless, it is crucial to emphasize that prolonged residence times may cause the photocatalytic effect to generate alternative byproducts rather than NOX ${NO_X }$ , consequence of excessive oxidation that could prove counterproductive. These findings emphasize the potential of plasma‐assisted nitrogen fixation technology in reducing energy costs and meeting the growing demand for sustainable nitrogen‐based fertilizers. [ABSTRACT FROM AUTHOR]

The photovoltaic (PV) module energy rating standard series IEC 61853 does not cover bifacial PV modules. However, the market share of bifacial PV modules has dramatically increased in recent years and is projected to grow. This work demonstrates how Parts 3 and 4 of the IEC 61853 standard could be extended to bifacial modules. First, we develop an irradiance model that uses the data already given in the standard IEC 61853‐4 to calculate the irradiance on the rear side of the module. Second, we propose a way to extend the energy yield calculation algorithm IEC 61853‐3 to include bifacial modules and make it available to the PV community. This rear irradiance and bifacial energy yield calculation procedure is tested using real outdoor measurements for a nine‐month period with a root mean square difference between measured and simulated energy yield of 4.65%. To conclude, we investigate the impact of different climates and normalization on the bifacial module energy rating results. [ABSTRACT FROM AUTHOR]

Biomass is a renewable alternative energy source with almost zero‐carbon footprint. This work focused on the physicochemical analysis and wet torrefaction of shea nut chaff (SNC) biomass. The SNC is a semi‐solid waste generated during the production process of shea nut butter and is least studied for its bioenergy potential. Wet torrefaction or hydrothermal carbonization studies of sun‐dried SNC were conducted at different temperatures (180–260°C), residence times (15–30 min) and water‐to‐biomass (W/B) ratios (5–15:1). Characterization studies of the torrefied biomass for different temperatures were conducted using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM) analyses. The best‐fit analysis of variance (ANOVA) model for wet torrefaction mass yield was 2FI, with p‐values of <0.05, and a regression coefficient (R2) of 0.9443. The yield of torrefied SNC attained at 260°C, 45 bar, W/B ratio of 5, and 10‐min residence time was 55.5 wt.%, and the corresponding energy yield was 89.5%. Both temperature and W/B ratio had significant effect on torrefaction yield. There was a significant improvement in the volatile matter, fixed carbon, moisture, and heating value reduction in the torrefied SNC compared to the raw SNC making it a potential bioenergy source. However, high ash content is a major concern even after torrefaction. [ABSTRACT FROM AUTHOR]

The temperature experienced by reactants during preparation in a reactor is a key component in determining the yield and homogeneity of usable chemical products such as biomass particles. Thermocouples with sensors can be used to monitor spatial temperature gradients within reactors but these sensors are often too expensive and/or invasive. The present work proposes a strategy to identify optimal machine learning models to infer the maximum effective temperature experienced by particles during oxidative biomass torrefaction using key thermochemical combustion parameters. The maximum rate of weight loss, the corresponding temperature, and fixed carbon content on a dry‐ash‐free basis are used as literature‐based predictor variables obtained from thermogravimetric analysis. The evaluation of 24 machine‐learning models using the standard tenfold cross‐validation method suggests that the exponential Gaussian process regression (GPR) model is the most effective, followed by other GPR models. These high‐performing GPR models were also utilized to predict the effective preparation temperature distribution of reactor‐produced biomass particles under eight conditions of varying residence time and air‐to‐biomass ratio. The effective preparation temperature and residence time of individual biomass particles were then encoded into the torrefaction severity factor and used to estimate the energy yield of the reactor output as a novel quality control method. © 2023 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

As photovoltaic modules are increasingly used in renewable energy systems, ensuring energy efficiency by reducing the levelized cost of electricity has become the focus of current research. Herein, the 1‐year performances of both monofacial and bifacial photovoltaic modules were monitored, compared, and analyzed at a solar carport system in the Korean peninsula. The environmental parameters during the four seasons were investigated for both systems under ambient conditions. Irradiance was determined as the primary influencing parameter in the system. The energy yield of the bifacial module system was 3.08% higher than that of the monofacial system owing to rear‐side absorption during the study period. The loss mechanism for this lower yield was determined by investigating the irradiance effect. It was attributed to low bifaciality due to cell properties (optical and electrical properties, and the sorting effect) and module properties (shading effects from the junction box cable and frame design, and glass grid effect), design of the carport system, and the albedo effect. These analyses revealed that the photovoltaic energy yield can be increased further by reducing these loss parameters at the carport system. This study can contribute to achieving higher energy yield from photovoltaic systems during field applications. [ABSTRACT FROM AUTHOR]

Bifacial perovskite (PVK)/crystalline silicon (c‐Si) tandem photovoltaic (PV) modules provide an effective strategy to further improve the efficiency and energy yield (EY) of c‐Si PV modules. In this work, the energy outputs of bifacial tandem PV modules under outdoor conditions are analyzed by combining optical modeling, one‐diode equivalent circuit model, module tilt angle, and meteorological data, and a detailed comparative study with bifacial silicon heterojunction (SHJ) PV modules is also performed. The bifacial PVK/c‐Si tandem modules exhibit higher EY in locations with strong direct normal irradiance regardless of the ground type with any albedo, while bifacial SHJ modules exhibit similar or even higher EY than tandem modules in locations with strong diffuse horizontal irradiance (DHI) such as Chengdu. Considering factors such as EY and levelized cost of electricity, Eg_PVK in the range of 1.58–1.62 eV is suitable for most application scenarios, while the deployment of bifacial SHJ PV modules is preferred in areas dominated by DHI, as represented by Chengdu. Herein, important implications for policy making in determining the cost‐effective type of PV modules are provided to generate renewable electricity. [ABSTRACT FROM AUTHOR]

In this work, a method to calculate the aerosol content in the atmosphere and the prevailing spectral irradiance of the sunlight is introduced. This method does not aim for low measurement uncertainty but for cost effectiveness and does not require sophisticated equipment. The bases of the method are the clear sky direct normal irradiance (DNI) and a look‐up table calculated with the software tool SMARTS2. The ratio of clear sky DNI to the prevailing DNI in combination with the look‐up table allows the determination of aerosol optical depth (AOD), spectral matching ratios (SMR), and spectral irradiances. Besides the prevailing DNI, the following ambient condition parameters are required: Air pressure, relative humidity, and ambient temperature. This means a weather station and a pyrheliometer are sufficient for the determination of the prevailing spectral irradiance. Obviously, this method cannot guarantee the same accuracy as conventional spectral irradiance measurement methods (e.g., using a spectroradiometer). However, in this work, we demonstrate the potential of this new method as a fall‐back strategy for missing spectral irradiance data. This method is worth using when (C)PV module power output data needs to be evaluated in dependence of the composition of the spectral irradiance, but no regular spectral irradiance data are available. In this paper, the AOD and SMR values determined with the introduced method are compared to measurement data with common measurement devices demonstrating a satisfying agreement. The spectral irradiances calculated with this method are successfully tested for using as the basis for energy yield calculations and for the determination of the CPV module power output at Concentrator Standard Conditions according to IEC 62670‐1. [ABSTRACT FROM AUTHOR]

A comprehensive algorithm for calculating the energy yield (EY) is used as the most important figure‐of‐merit in determining the capabilities of PV devices in realistic operation. The model is based on advanced optical modeling and extensive opto‐thermo‐electrical characterization. It takes the realistic environmental and device installation data fully into account, as well as the complete set of device specifications including all relevant temperature‐induced variations. A detailed analysis and optimization of two‐terminal perovskite‐silicon tandem devices are done in terms of long‐term electrical energy production at different geographical locations from distinct Köppen–Geiger–Photovoltaic climate zones (KGPV). It is shown that the optimal perovskite bandgap (EG,PK) in a tandem device operating under realistic conditions is in all cases higher than the one optimized under STC, yet does not differ significantly from location to location, which is beneficial from the manufacturing point of view. The optimal EG,PK is influenced primarily by the spectral distribution of incident irradiance, and not so much by the operating temperature conditions. Moreover, a clear linear dependency between the optimal EG,PK and the weighted average photon energy of the incident irradiance is demonstrated, which presents an important rule for rapid tandem design. [ABSTRACT FROM AUTHOR]

All‐perovskite two‐terminal tandem photovoltaics offer high power conversion efficiencies (PCEs) that can surpass the limits of single‐junction photovoltaics. In this study, energy yield (EY) simulations are performed to assess the performance of bifacial all‐perovskite tandem solar cells. Under standard test conditions, in the absence of albedo, bifacial tandems demonstrate a 4.9% relative lower PCE compared to equivalent monofacial tandems due to transparency losses at the semitransparent rear side. However, under realistic irradiation conditions, albedo irradiation leads to an enhancement in EY for bifacial cells. This enhancement enables bifacial cells to produce more energy than monofacial cells, even over relatively low average reflectance (RA) ground such as dark sandstone (RA = 9%). The EY gain for bifacial cells rises to a maximum of 40–50% for ground modeled as a perfect reflector (RA = 100%), accompanied by a shift in optimum top subcell bandgap to 1.56 eV. This shift is of particular interest as low‐bandgap perovskite semiconductors (with lower bromide concentrations) offer enhanced stability under realistic operation conditions. Finally, this work presents a route to increase the PCE of simulated monofacial and bifacial cells, to 31.9% and 30.8%, respectively, by optimizing the optical and electrical performance of the cells. [ABSTRACT FROM AUTHOR]

Energy yield calculations for CPV modules that use tandem solar cell technology have been performed and analysed in this work. Two BSQ D280 CPV modules were used as specimen: one located in Freiburg, Germany, and one in Greater Noida, India. The current–voltage curves of both modules were measured for several months together with the prevailing ambient conditions. The energy yield in the respective measurement periods were calculated using the software PVsyst. It has been found that the energy yield modelled with PVsyst has a good agreement with the one measured in Freiburg, but deviates by 10% from the one measured in Greater Noida. The reason is most likely the high aerosol content in Greater Noida and thus the non‐appropriate consideration of spectral irradiance impact by PVsyst, which uses air mass and DNI as the only atmospherical parameters. The accuracy of the PVsyst calculation has been strongly improved in this work by using SMR corrected DNI values as input for the PVsyst calculation. In this manner, the impact of spectral irradiance variation on (C)PV module power output can be considered in energy yield calculations by PVsyst. The deviation of the calculated and measured energy yield could be reduced to below 1%. [ABSTRACT FROM AUTHOR]

Accurate photovoltaic (PV) power forecasting is an essential tool that enables the efficient integration of solar electricity and energy trading. This work proposes a novel methodology for the implementation of a forecasting tool that provides aggregated PV production day‐ahead forecasts for the PV systems installed at a distribution level. Specifically, the tool is a cloud‐based platform, comprising of a data quality block, a weather forecasting model, a machine learning power prediction step and an up‐scaling aggregation stage. In this context and in the absence of a fully observable distribution system, the aggregated PV generation was estimated using a clustering approach and up‐scaling the measured generation of reference systems to the aggregated installed capacity. The results demonstrated that the implemented tool exhibited high forecasting accuracies, lower than 10% given by the mean absolute percentage error when applied to the distribution system of Cyprus. Furthermore, the comparative benchmarking of the up‐scaling techniques against the estimated aggregated PV generation demonstrated that the best‐performing approach was the hybrid model, which provided a normalised root mean square error of 10.29% and mean absolute percentage error of 9.11%. Finally, useful information is provided for establishing a robust day‐ahead forecasting methodology that is based on an optimal supervised learning and hybrid up‐scaling approach. [ABSTRACT FROM AUTHOR]

Energy production of perovskite‐based photovoltaic (PV) technology can be increased not only by improving device efficiency of perovskite solar cells (PVSCs) but also by innovative concepts such as bifacial and tandem configurations which require low‐damage and highly transparent top electrodes. Herein, an amorphous CdO‐In2O3 alloy film with high transparency and low resistivity and its application in a bifacial PVSC and a perovskite/Si 4T tandem solar cell are reported. Due to the high optical transmittance, the CdO‐In2O3‐based PVSC shows a high bifaciality factor of 84.0%, and the CdO‐In2O3‐based perovskite/Si 4T tandem solar cell achieves a champion power conversion efficiency of 25.12%, much higher than the indium tin oxide based tandem cell. Finally, a yearly energy yield calculation and levelized cost of energy (LCOE) analysis for these PV technologies (together with Si single‐junction solar cells as a reference) in Singapore, Australia, and Germany are conducted. The results demonstrate the potential of CdO‐In2O3‐based perovskite PV technologies, yet more efforts are still required to further reduce the manufacturing cost to achieve competitive LCOE values in countries with relatively low PV installation cost. [ABSTRACT FROM AUTHOR]

Dairy industry effluent will pollute the environment if not properly treated. In the present work, the feasibility of nonthermal plasma (NTP) for the treatment of dairy industry effluent is assessed. The effect of energy yield and plasma intensity on reduction of Chemical Oxygen Demand (COD) removal is investigated. Box–Behnken design (BBD) is employed to optimize the operating parameters such as initial pH (5–9), reaction time (4–8 h), effluent flow rate (10–90 ml/min) and applied voltage (20–30 kV) where COD and energy yield are taken as responses. The optimum condition for COD removal and energy yield is same with a pH of 9, effluent flow rate of 10 ml/min and applied voltage of 30 kVp‐p, whereas reaction time differs as 8 and 4 h, respectively. COD reduction of 52% indicates that NTP process is a promising technology for dairy effluent treatment. [ABSTRACT FROM AUTHOR]

Spectral differences affect solar cell performance, an effect that is especially visible when comparing different solar cell technologies. To reproduce the impact of varying spectra on solar cell performance in the lab, a unique classification of spectra is needed, which is currently missing in literature. The most commonly used classification, average photon energy (APE), is not unique, and a single APE value may represent various spectra depending on location. In this work, we propose a classification method based on an iterative use of the k‐means clustering algorithm. We call this method RISE (Representative Identification of Spectra and the Environment). We define a set of 18 spectra using RISE and reproduce the spectral impact on energy yield for various solar cell technologies and locations. We explore effects on yield for commercially available solar cell technologies (Si and CdTe) in four locations: Singapore (fully humid equatorial climate), Colorado (cold arid), Brazil (warm, humid, and subtropical), and Denmark (fully humid warm temperature). We then reduce our findings to practice by implementing the spectrum set into an LED current–voltage (IV) tester. We verify our performance predictions using our set of representative spectra to reproduce energy yield differences between Si solar cells and CdTe solar cells with an average error of less than 1.5 ± 0.5% as compared to over 5% when using standard testing conditions. [ABSTRACT FROM AUTHOR]

Summary: Building‐integrated photovoltaics (BIPV) is an innovative green solution that incorporated energy generation into the building façade with modification on the building material or architectural structure. It is a clean and reliable solution that conserves the aesthetical value of the architecture and has the potential to enhance the building's energy efficiency. Malaysia's tropical location has a high solar energy potential to be exploited, and BIPV is a very innovative aspect of technology to employ the available energy. Heriot‐Watt University Malaysia (HWUM) has a unique roof design that could be utilized as an application of the BIPV system to generate electricity, reducing the carbon footprint of the facility. Eight BIPV systems of different PV technologies and module types and with capacities of 411.8 to 1085.6 kW were proposed for the building. The environmental plugin software has been integrated with a building geometry modelling tool to visualize and estimate the energy potential from the roof surface in a 3D modelling software. Additionally, detailed system simulations are conducted using PVSyst software, where results and performance parameters are analysed. The roof surface is shown to provide great energy potential and studied scenarios generated between 548 and 1451 MWh yearly with PR range from 78% to 85%. C‐Si scenarios offer the best economical profitability with payback period of 4.4 to 6.3 years. The recommended scenario has a size of 1085.5 kW and utilizes thin‐film CdTe PV modules. The system generates 1415 MWh annually with a performance ratio of 84.9%, which saves 62.8% of the electricity bill and has an estimated cost of 901 000 USD. Installation of the proposed system should preserve the aesthetical value of the building's roof, satisfy BIPV rules, and most importantly, conserves energy, making the building greener. [ABSTRACT FROM AUTHOR]

The efficiency of solar panels declines from its rated (standard testing conditions) value under low irradiance which typically occurs in the mornings, evenings and on cloudy days. In this work, the authors evaluate cadmium telluride (CdTe) thin film panels due to their increasing market share and assess their low irradiance performance in comparison with conventional crystalline‐Silicon (c‐Si) panels. The performance of both material systems is analysed for a 4‐year period to evaluate their performance in terms of their relative change in efficiency and energy yield. Further analysis on a high‐resolution 8‐day measured data for winters and summers shows that CdTe panels provide ∼1.09% higher specific energy yield compared to c‐Si panels. This primarily occurs due to higher CdTe bandgap and better spectral response at lower insolation levels resulting in an enhanced relative efficiency with respect to c‐Si panels. [ABSTRACT FROM AUTHOR]

In future power systems with little system inertia, grid operators will require the provision of synthetic inertia (SI) from renewable energy sources. Unlike today, grid operators may require continuous provision of SI. This can lead to an unwanted disconnection of wind turbine generators (WTGs) from the grid, and has the potential to cause a significant decrease of the energy yield and financial losses for the turbine operator. In order to avoid such situations a controller is proposed, which interprets the grid codes to the benefit of all parties involved. This can be achieved by a variable inertia constant, which changes with the operating point of the WTG. In this study, the behaviour of the variable inertia constant controller is described, assessed and verified with time domain simulations. [ABSTRACT FROM AUTHOR]

This study presents a new formulation for real‐time active network management (ANM) control of distribution networks to maximise energy yield from distributed generation (DG). Coordinated scheduling of renewable DG and distribution network control assets can limit DG curtailment and significantly increase energy yield and economic performance of DG in weak or congested networks. Optimal power flow (OPF) has been employed in the literature for this purpose. However, single time frame snapshot formulations are limited by their narrow interpretation of temporal constraints. Here a formulation is presented for a new receding‐horizon OPF technique to better control real‐time ANM in distribution networks with high levels of temporally and spatially variable renewable DG. It is shown to improve the coordination between time sequences of system dispatch and improve voltage performance. [ABSTRACT FROM AUTHOR]

Greenhouse gas ( GHG) intensity is frequently used to assess the mitigation potential of biofuels; however, failure to quantify other environmental impacts may result in unintended consequences, effectively shifting the environmental burden of fuel production rather than reducing it. We modeled production of E85, a gasoline/ethanol blend, from forage sorghum ( Sorghum bicolor cv. photoperiod LS) grown, processed, and consumed in California's Imperial Valley in order to evaluate the influence of nitrogen (N) management on well-to-wheel ( WTW) environmental impacts from cellulosic ethanol. We simulated 25 N management scenarios varying application rate, application method, and N source. Life cycle environmental impacts were characterized using the EPA's criteria for emissions affecting the environment and human health. Our results suggest efficient use of N is an important pathway for minimizing WTW emissions on an energy yield basis. Simulations in which N was injected had the highest nitrogen use efficiency. Even at rates as high as 450 kg N ha−1, injected N simulations generated a yield response sufficient to outweigh accompanying increases in most N-induced emissions on an energy yield basis. Thus, within the biofuel life cycle, trade-offs across productivity, GHG intensity, and pollutant loads may be possible to avoid at regional to global scales. However, trade-offs were seemingly unavoidable when impacts from E85 were compared to those of conventional gasoline. The GHG intensity of sorghum-derived E85 ranged from 29 to 44 g CO2 eq MJ−1, roughly 1/3 to 1/2 that of gasoline. Conversely, emissions contributing to local air and water pollution tended to be substantially higher in the E85 life cycle. These adverse impacts were strongly influenced by N management and could be partially mitigated by efficient application of N fertilizers. Together, our results emphasize the importance of minimizing on-farm emissions in maximizing both the environmental benefits and profitability of biofuels. [ABSTRACT FROM AUTHOR]

The current-voltage (I-V) characteristics of 15 different photovoltaic modules are monitored during more than 2 years of operation at four locations (Germany, Italy, India and Arizona) corresponding to four different climate zones. The electrical stability of the photovoltaic modules during the time of outdoor exposure is investigated in terms of measured I-V curve translated to standard test conditions. This translation compensates the influence of module temperature, irradiance, spectral effects and soiling on the I-V curves. The changes of output power after these corrections are attributed to initial consolidation phases, to long-term degradation of the electrical properties and to seasonal cycles associated with metastabilities. Modules made from crystalline Si turn out to show no or only minor effects. Thin-Film modules (CdTe, Cu(In,Ga)Se2 and thin-film Si) exhibit a wide spread of metastable behaviour with consistent patterns for identical modules in different climates but with significant differences amongst different manufacturers of the same thin-film technology. We show further that this metastable behaviour influences the energy yield of the modules. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper quantifies the impact of distributed power electronics in photovoltaic (PV) systems in terms of end-of-life energy-capture performance and reliability. The analysis is based on simulations of PV installations over system lifetime at various degradation rates. It is shown how module-level or submodule-level power converters can mitigate variations in cell degradation over time, effectively increasing the system lifespan by 5-10 years compared with the nominal 25-year lifetime. An important aspect typically overlooked when characterizing such improvements is the reliability of distributed power electronics, as power converter failures may not only diminish energy yield improvements but also adversely affect the overall system operation. Failure models are developed, and power electronics reliability is taken into account in this work, in order to provide a more comprehensive view of the opportunities and limitations offered by distributed power electronics in PV systems. It is shown how a differential power-processing approach achieves the best mismatch mitigation performance and the least susceptibility to converter faults. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Nowadays plant monitoring and control of renewable energy sources can take advantage of the use of unmanned aerial technologies. This manuscript aims to develop an image post‐processing tool for remote aerial images able to help operation and maintenance operators in photovoltaic (PV) defects detection using light unmanned aerial vehicles (UAVs). In particular, PV systems deployed in the field in the last ten years show often critical behaviour with a range of failures able to compromise the performance and energy yield of the power plants, thus they can greatly benefit of such novel technologies and tools. The described procedures are here tested on real plant data, with different kind of sensors, in order to find out potential advantages in fast fault detection tasks, using an automatic system for PV plants' mapping. The results of this research will be reported in order to provide an understanding of potential impact of image processing techniques based on UAV in the renewable energy sector. [ABSTRACT FROM AUTHOR]

The energy yield of 15 different photovoltaic module technologies is measured during one year of operation at four locations (Germany, Italy, India, Arizona) corresponding to four different climate zones. The data are analysed in terms of a linear performance loss analysis for the module performance ratio (MPR) taking into account the influence of module temperature, low irradiance conditions, spectral and angular effects and soiling. This analysis is based on an independent characterisation of the modules in the laboratory combined with site specific data accumulated during operation. The model predicts trends of the measured MPR due to different module technologies and different locations. [ABSTRACT FROM AUTHOR]

For better conversion of sunlight into electricity, advanced architectures of multi-junction (MJ) solar cells include increasing numbers of subcells. The Achilles' heel of these cells lies in their increased sensitivity to the spectral distribution of sunlight, which is likely to significantly alter their performance during real working operation. This study investigates the capacity of MJ solar cells comprising up to 10 subcells to accommodate a wide range of spectral characteristics of the incident radiation. A systematic study is performed, aimed at a realistic estimation of the energy output of MJ-based concentrating photovoltaic systems at characteristic locations selected to represent a large range of climatic conditions. We show that optimal MJ architectures could have between 4 and 7 subcells. Beyond seven subcells, the slight gains in peak efficiency are likely outweighed by detrimental increases in dependence on local conditions and in annual yield variability. The relevance of considering either conversion efficiency or modeled energy output as the most appropriate indicator of the cell performance, when considering advanced architectures of MJ solar cells, is also discussed. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Partial shading causes power loss in a photovoltaic module by inducing a power mismatch within the module. This power loss can be significant in building-applied and building-integrated photovoltaic installations. Given the often repetitive nature of shade profiles in such applications, we propose to employ non-reconfigurable or static configurations. We use our simulation tool to precompute static configurations, apply shading scenarios, such as a chimney or tree shade, and make a comparison between the energy yields of different static configurations, which includes that of a conventional module. We then identify the configuration characteristics that consistently yield a higher energy. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We identify the key inputs and measurement data needed for accurate energy rating of concentrator photovoltaic (CPV) modules based on field observations of multiple CPV modules. Acceptance angle is shown to correlate with the observed module-level performance ratio (PR) for the modules studied. Using power ratings based on concentrator standard test conditions, PRs between 90% and 95% were observed during the summers with up to ~10% lower PRs during the winters. A module fabricated by Semprius showed 94% ±0.7% PR over almost 2 years with seasonal variation in PR of less than 1% showing how a module with relatively large acceptance angle may show very consistent average efficiency (calculated from the energy generated relative to the energy available), potentially simplifying energy ratings. The application of the results for translation of energy rating from one location to another is discussed, concluding that most of the translation differences may be correlated with temperature differences between sites with the largest variation happening when optical efficiency depends on temperature. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT The performance of concentrator photovoltaic systems can be characterised by the power output under reference conditions and the output energy yield under realistic solar illumination. For a range of locations, the frequency distribution of individual atmospheric parameters and their quantitative impact on power output of a concentrator photovoltaic system have been evaluated, with aerosols shown to have a substantial impact on performance at many sites. Limited knowledge of atmospheric parameters results in a difference of up to 75% in simulated energy yield over an annual period and up to 75% deviation in the expected levelised cost of energy. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT The effect of varying the averaging time of measured data used to calculate wind turbine power curves is examined. The effects of reducing the averaging time from 10 to 1 min, as recommended for small wind turbines, are investigated using power performance data recorded using a 15 kW wind turbine. Test site data have been processed according to the relevant international standard, IEC 61400-12-1, to provide power curves and annual energy yield predictions. A number of issues are explored: the systematic distortion of the power curve that occurs as averaging time is decreased, the errors introduced by the use of 1 min averaged power curves to calculate energy yield and the reduction of turbulence intensity as averaging time is reduced. Recommendations for improved small wind turbine testing and energy yield calculation are given. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Degradation of phenol in water was examined in a non-thermal plasma reactor combined with CeO2, Fe2O3/CeO2, and ZrO2/CeO2 catalysts. Plasma reactor was operated in a dielectric barrier discharge configuration, whereas, catalysts were characterized by XRD, BET, and Raman spectroscopy. The effect of applied voltage, phenol concentration and catalyst addition was studied. Typical results indicated that the degradation efficiency increases with increasing voltage, whereas, the best energy yield was obtained at lower applied voltage. Total organic carbon analyzer confirmed the mineralization of phenol, which was further enhanced by the catalyst addition up to 47.3%. The intermediate compounds formed during the plasma decomposition were identified by gas chromatography mass spectrometry (GC-MS). [ABSTRACT FROM AUTHOR]

In the search for new transport fuels from renewable resources, biodiesel from microbial lipids comes into view. We have evaluated the lipid yield and energy use of a process for production of biodiesel from agricultural waste using lipid-accumulating yeast and fungi. We included different bioreactors for submerged and solid-state fermentation in our evaluation. Using existing kinetic models, we predict lipid yields on substrate between 5% and 19% ( w/w), depending on the culture system. According to the same models, improvement of the yield to 25-30% ( w/w) is possible, for example by genetic modification of the micro-organisms. The net energy ratio of the non-optimized systems varies between 0.8 and 2.5 MJ produced per MJ used; energy use for pre-treatment and for oxygen transfer are most important. For the optimized systems, the net energy ratio increases to 2.9-5.5 MJ produced per MJ used, which can compete very well with other biofuels such as bioethanol or algal biodiesel. This shows that, although quite some work still has to be done, microbial lipids have the potential to be tomorrow's source of biodiesel. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

ABSTRACT Mathematical, empirical, and electrical models have long been implemented and used to predict the energy yield of many photovoltaic (PV) technologies. The purpose of this paper is to compare the annual DC energy yield prediction errors of four models namely the single-point efficiency, single-point efficiency with temperature correction, the Photovoltaic for Utility-Scale Applications (PVUSA), and the one-diode model, against outdoor measurements for different grid-connected PV systems in Cyprus over a 4-year evaluation period. The different models showed a wide variation of prediction errors, demonstrating a strong dependence between model performance and the different technologies. In particular, it was clearly shown that the application of temperature loss correction based on the manufacturer's temperature coefficients of power at maximum power point assisted in improving the energy yield prediction significantly especially for the crystalline silicon (c-Si) technologies. In most cases, the best agreement between the modeled results and outdoor-measured annual DC energy yield for mono-crystalline silicon (mono-c-Si) and multi-crystalline silicon (multi-c-Si) technologies was obtained using the one-diode model. The energy yield for the thin-film technologies was more accurately predicted using the PVUSA model with the exception of the copper-indium-gallium-diselenide (CIGS) technology, which was best predicted using the single-point efficiency with temperature correction and one-diode models, thus demonstrating similar physical properties to c-Si technologies. The paper further quantifies the combined uncertainties associated with the predicted energy yield as a function of the input parameters for the single-point efficiency, single-point efficiency with temperature correction, and the PVUSA models. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT The long-term performance and reliability of photovoltaic (PV) modules and systems are critical metrics for the economic viability of PV as a power source. In this study, the power degradation rates of two identical PV systems deployed in Florida are quantified using the Performance Ratio analytical technique and the translation of power output to an alternative reporting condition of 1000 W m−2 irradiance and cell temperature of 50 °C. We introduce a multi-pronged strategy for quantifying the degradation rates of PV modules and arrays using archived data. This multi-pronged approach utilizes nearby weather stations to validate and, if needed, correct suspect environmental data that can be a problem when sensor calibrations may have drifted. Recent field measurements, including I-V curve measurements of the arrays, visual inspection, and infrared imaging, are then used to further investigate the performance of these systems. Finally, the degradation rates and calculated uncertainties are reported for both systems using the methods described previously. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Sustainable cities require the generation of energy from waste that cannot be economically reused or recycled. This study focuses on slow pyrolysis that can generate a high yield of char along with liquid and gas products from waste. Char is high in energy content, storable and transportable with low cost so that it can be used as an intermediate medium for high efficiency energy conversion. Pre-processed municipal waste pellets, wood and grass were pyrolysed in a batch type reactor for a final temperature ranging from 350 to 700°C, and the char products were characterized. The mass yields of char ranged from 55 to 20% for the tested temperature range, recovering 70–30% of energy and 62–30% of carbon in the raw material. The gross calorific value of char was 30–35 MJ kg-1 on a dry ash free basis. The ash content of raw materials was a key parameter for the quality of char, since its proportion increased by 2–4 times in char depending on the mass yield. A significant amount of volatile metals such as Hg, As and Pb in the waste sample was evaporated at 500°C. Therefore, evaporation of volatile metals was another important parameter in determining the pyrolysis temperature and fuel residence time. The char did not show significant morphological change in the tested range of temperatures. It was concluded that slow pyrolysis of waste for char production should be performed below 500°C in order to increase the energy yield and also to reduce the evaporation of heavy metals. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this study, energy yield of a photovoltaic (PV) system is predicted from the output peak power of an individual PV module. Measured energy yield of an individual back contact single crystalline silicon PV module is scaled with total number of PV module within the PV array to calculate the energy yield. Regarding the conversion efficiency of the inverter in the PV system, calculated and measured energy yield of PV system were compared for selected dates. To confirm the accuracy of the proposed model, days with clear and cloudy irradiation profile were selected from August and November. The difference between calculated and measured energy yield of PV array were found to be insignificant. Thus, current method which is straightforward, feasible and reliable to predict the energy yield of PV array using just an individual PV module. [ABSTRACT FROM AUTHOR]

Malaysia targets to become the second‐largest producer of solar photovoltaic (PV) in the world by increasing the current output from 12% to 20% in 2020. The government also expects to achieve 45% reduction of greenhouse gas emission by 2030 through renewable energy mainly by solar PV. Large‐scale solar (LSS) aims to produce 2.5 GW, which contributes to 10% of the nation's electricity demands. The LSS system is held back by the grid‐scale integration, transmission, and distribution infrastructure. Thus, power system analysis is crucial to achieve optimization in LSS to power grid integration. This paper investigates various power system analysis models and recommends an optimized configuration based on Malaysia's LSS scenario. In stage 1, an optimal PV sizing is carried out based on real data of LSS installation in different locations. In stage 2, power analysis is carried out using to analyze the potential difference variation when connected to a nine‐bus power system. The potential variation at each bus of the system is assessed and hence provides a feasibility statement on the most effective configurations for LSS–grid integration. This paper serves as the reference model for LSS–grid integration in Malaysia and is expected to be replicated in the other countries with similar conditions. [ABSTRACT FROM AUTHOR]