Bifacial Technology Research Articles

Outdoor Performance Analysis of Semitransparent Photovoltaic Windows with Bifacial Cells and Integrated Blinds

The stricter requirements for the energy performance of buildings are creating a market for several building‐integrated photovoltaic (BIPV) technologies, including photovoltaic (PV) windows. Herein, an innovative multifunctional PV window concept designed to enhance energy generation while providing overheating protection for better indoor thermal and visual comfort is presented. This concept utilizes bifacial c‐Si solar cell strips combined with venetian blinds, all embedded in a unique insulating glazing unit. The bifacial technology increases the energy yield by using the blinds as reflectors, directing more irradiance to the cells’ rear side. The goal of this study is to analyze the outdoor performance of this concept under real operating conditions. Twelve demonstrators are installed and monitored. Various measurement campaigns are conducted, examining the impact of different blind types, tilt angles, sun positions and sky conditions. The highest energy boosts occur when the blinds are fully closed at a 75° angle with their convex side facing outward. Blinds with the highest specular reflectance achieve a maximum performance increase of 25% on sunny days and a daily average increase of 12% compared to the case of no blinds.

PVSails: Harnessing Innovation With Vertical Bifacial PV Modules in Floating Photovoltaic Systems

AbstractIn the context of offshore floating photovoltaic systems (FPVs), this paper explores the use of bifacial photovoltaic modules installed in the vertical position. The energy harvested from the rear face of vertically configured bifacial PV modules compensates for the reduced production at the front face of the module, and this demonstrates the potential of bifacial technology for offshore applications. By comparison, most existing horizontally tilted bifacial FPV systems gain only a small benefit in production from the rear face of the module due to the minimum radiation received, and what also must be taken into consideration is the negative effect of significant soiling owing to the low tilt angle of the PV modules. Hence, to overcome these drawbacks, we have developed the innovative “PVSail” concept, which explores the deployment of vertical FPV systems on floats, buoys, or poles/minipiles. Floating vertical bifacial PV systems (VBPVs) have huge potential to harness all the energy generation capabilities enhance by reflected light, especially from snow‐covered surfaces in northern regions. Our analysis considers a patented mooring and vertical PV system that allows the VBPV structure to align with the prevailing wind direction to shed wind loads, and our numerical analysis explores the potential of VBPV applied to Catania in Italy and Nigg Bay in the United Kingdom. Our analysis study has revealed that across an azimuth angle range (0°–180°), vertical bifacial modules experience roughly a 9% decrease in energy yield at Catania and about a 5% energy yield gain in higher latitude regions like Nigg Bay. Additionally, increasing the latitude of the installation location of VBPV reduces the energy yield sensitivity to the orientation, that is, azimuth angle. The PVSail concept opens the door to novel deployment possibilities in offshore renewable energy projects.

Characterization of bifacial technology Pv systems

Bifacial solar technology has experienced exponential growth in recent years and its trend is increasing for the coming years. Considering the advantages that it offers over monofacial technology such as its current price equivalence, the increase in performance thanks to the production of the rear face and the consecutive reduction of the LCOE, it is logical that more and more photovoltaic plants with this technology are been installed. Nowadays, there are some regulatory gaps regarding bifacial technology and, due to this growing trend, it is necessary to study, research and implement the optimal way to evaluate these systems. This article has experimented with a 3.3 kW bifacial photovoltaic system, divided into two strings with different configurations, whose monitoring system has all the instrumentation included in the IEC 61,724 standard, with the addition that it has several rear irradiance sensors arranged in different locations of the system to evaluate the variability of this parameter. After an experimental campaign of 9 months, a power estimation analysis and the calculation of the PR and PR25°C have been carried out using the different rear irradiance sensors. The variability of this parameter depending on the location of the sensor has affected the results in such a way that the RMSE committed in the power estimation has varied between 10.22% and 2.63%, while the PR and PR25°C of the system has oscillated between 0.84 for the most unfavorable case and 0.95 in the most favorable case. Assumed the great variability between performance ratios, it is necessary to establish a specific normative standard for the evaluation of Bifacial PV systems.

Performance Analysis of Triple‐Cation Mixed‐Halide Bifacial Perovskite Solar Cell with 17% Rear and 25% Front Efficiency

The goal of bifacial technology is to increase the efficiency of solar cells (SC) by capturing albedo sunlight and converting it to electrical energy. The use of triple‐cation mixed‐halide perovskite solar cells (PSC) has sparked a lot of curiosity and could be the potential for improved power conversion efficiency (PCE) associated with traditional PSCs. Herein, n–i–p‐configured triple‐cation mixed‐halide‐based bifacial PSC is studied using the SC capacitance simulator 1D tool. Through our simulation, the impact of thickness in electron and hole transport layers (ETL and HTLs), defect density, doping density, and the thickness of the light‐harvesting layer on the device performance is examined. With an optimal design, the device exhibits an absolutely staggering efficiency of 25.28% from the front side and around 17.19% from the rear. This cell, due to its high albedo absorption, linearly enhances the short‐circuit current; hence, it overcomes the classical current‐matching limit of ordinary PSCs. The proposed device FTO/TiO2/[Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3]/CuSbS2 has a remarkable efficiency that increases linearly with albedo, making it very appealing for new, high‐efficiency solar applications.

Accurate modelling of the bifacial gain potential of rooftop solar photovoltaic systems

Bifacial solar modules have emerged as a promising technology in utility-scale photovoltaic systems, experiencing significant growth and capturing a substantial market share worldwide, as reported by the International Technology Roadmap for Photovoltaic (ITRPV) 2023. Despite this progress, the potential of bifacial modules in rooftop applications remains largely unexplored. This paper aims to address this knowledge gap by conducting a comprehensive study utilizing Monte Carlo Ray Tracing techniques coupled with detailed electrical modelling. The primary objective of this study is to investigate the viability of implementing bifacial solar modules on rooftops by examining the potential energy yield gains. By conducting a detailed analysis on a representative rooftop in Canberra, Australia, real-world conditions, and variations are incorporated, providing a more accurate assessment of the energy yield gains achievable in such settings. The simulation results reveal that the implementation of bifacial solar modules on rooftops within Australia can result in energy yield gains of up to 22.6%. These findings demonstrate the considerable potential of bifacial technology in maximizing solar energy production in rooftop applications. The analysis shows significant implications of module and system design on the potential gain. For example, electrical optimisation of individual modules in a system accounted for 1.4% of the bifacial gain. The analysis considers full annual time-step simulation, typical mechanical mounting components, installation orientations and module characteristics, ensuring practical relevance and reliability of the results.

Exploring Acheulean biface diversity in the central Narmada Valley, Madhya Pradesh, India

Central India occupies a pivotal place in the study of the Indian Palaeolithic. It is rich in Lower Palaeolithic records, with over 300 occurrences reported, and the region's antiquity is at least 800 Ka or older. The central Narmada Valley remains one of the crucial regions in Central India with a high frequency of Acheulean sites, which are primarily observed in the regolith deposits derived from the Vindhyan Supergroup. It is observed that most of the Acheulean sites are to the north of the Narmada River, and with fewer sites to the south. One possible reason could be that multiple hominin populations occupied this region, and the central Narmada Valley acted as a corridor for multidirectional movement in the past. This paper presents preliminary research on different lithic bifacial forms at various Acheulean sites in the central Narmada Valley. This study presents an analysis of 733 bifaces which are typologically divided into cleavers (57.1%), handaxes (35.1%) and miscellaneous (7.8%) specimens. The spatial distribution of these biface forms shows that cleavers are prominently present in the Northern zone, while handaxes are more prevalent in the Central zone. This research discusses various technological aspects of Acheulean bifacial technology in the central Narmada Valley and provides broad implications regarding the hominin occupation in the Indian Subcontinent.

Thermal or photovoltaic rear sides? A parametric comparison between photovoltaic thermal and bifacial technology

The photovoltaic generation has experienced high growth in recent years. However, more effort is needed to get on track with the net-zero scenario. The use of the photovoltaic modules' rear part can increase their electricity generation by controlling their temperature (hybrid photovoltaic/thermal solutions) or by adding conversion capability to the backside (bifacial modules). However, which solution is more effective in increasing energy yield, and under what conditions? To answer these questions, the authors conducted a worldwide comparative parametric study considering a wide range of site conditions and photovoltaic module specifications. Two relevant results came from the study. The first is a global technical competitive analysis to determine favorable site and module specifications for each rear-side utilization alternative. The second is the mathematical expression of a new parameter named “critical bifaciality,” which expresses the minimum bifaciality rate required to obtain a performance superior to similar monofacial photovoltaic-thermal modules. This parameter serves as a design rule for the selection specification of the bifacial system, which depends on both the location’s climate and site conditions. It also permits determining the feasible locations for adopting either technology based on electricity production. The study concludes that using bifacial modules is the most effective way to increase electricity generation. For typical site conditions (albedo = 0.3), module specifications (cell efficiency = 20%, and Temperature coefficient (-0.3%/°C), the energy benefit can range from 1 to 5% near the equator and more than 25% near the poles.

Optimal ground coverage ratios for tracked, fixed-tilt, and vertical photovoltaic systems for latitudes up to 75°N

General guidelines for determining the layout of photovoltaic (PV) arrays were historically developed for monofacial fixed-tilt systems at low-to-moderate latitudes. As the PV market progresses toward bifacial technologies, tracked systems, higher latitudes, and land-constrained areas, updated flexible and representational guidelines are required. Using our 3D view-factor PV system model, DUET, we provide formulae for ground coverage ratios (GCRs –i.e., the ratio between PV collector length and row pitch) providing 5%, 10%, and 15% shading loss as a function of mounting type and module type (bifacial vs monofacial) between 17-75°N. Fixed-tilt arrays span a wide range of GCR (0.15–0.68, 5% loss) compared to single-axis tracked arrays (0.17–0.32) and vertical east–west arrays (0.11–0.16). We additionally optimize fixed-tilt module tilt, finding that the optimum tilt can vary from 7° above latitude-tilt to 60° below latitude-tilt in certain cases. We demonstrate that tracked and fixed-tilt PV arrays should have similar GCRs >55°N, but tracked systems are more sensitive to row-to-row shading losses <55°N. The GCR of fixed-tilt arrays at lower latitudes can reach 0.55 without introducing >2.5% shading loss, whereas tracked and vertical arrays reach 2.5% shading loss by GCRs <0.22 and <0.10, respectively. We additionally find that bifacial PV arrays require GCRs up to 0.03 lower than monofacial GCRs. These results can inform future deployment designs for latitudes >15°N.

Multiphysics simulation of bifacial photovoltaic modules and software comparison

The solar energy industry is in constant evolution and the use of bifacials photovoltaic (PV) modules is one of the most recent innovations the industry adoptions. And even though bifacial technology has been present for as long as the monofacial technologies, bifacial solar modules have started to attract a lot of market attention; in fact, recent studies point out that the increasing interest for bifacial PV has aroused so much to predict a market share of 70% in 2030. The key feature that makes this possible is its design, which allows the module to capture sunlight from both sides of the panel increasing solar generation capacity by up to 25%, however this depends on factors such as: the irradiance factors, the module efficiency, the ground albedo, the tilt angle, the elevated height to the ground of the structure, the inter-row spacing and the array shading. Modeling and simulation of photovoltaic (PV) modules play an important role for technology development and evaluation of new designs and their interaction with the previously mentioned key factors. The project intends to analyze and comparing two irradiance numerical models. This comparison is made by simulating an identical bifacial PV solar installation (set-up) but using two different software with the capacity to carry out this type of analysis. Firstly, the study using PVsyst software, known for its widespread application in solar energy, and the other software was COMSOL Multiphysics, a Finite Element Method (FEM) based multiphysics simulation software to study and analyze optical and thermal performance of PV modules. For this comparative study, fixed irradiance conditions (during the year) were established, such as the equinoxes and solstices, to have different irradiance conditions and study their effect on the modeled bifacial modules. Finally, parametric studies of the following factors (design parameters) were carried out: ground albedo, tilt angle, inter-row spacing and height to the ground. In order to study the changes that these cause in the behavior of our system and also as a complement to this study and considering the great importance of the albedo for a bifacial installation, a field work has been carried out to measure it experimentally and validate the simulations.

Leaf wax isotopes reveal distinct hominin paleoenvironments in the Eastern Qinling Mountains of central China

Here, we present the first leaf wax record in association with Paleolithic occupations in the Eastern Qinling Mountains of central China. This region has been the focus of numerous archaeological projects, as it contains evidence of some of the oldest (∼2.0–1.2 Ma) hominin occupations in eastern Eurasia and is one of the key areas yielding bifacial handaxe technology. Previous research demonstrates that these mountains represent a physio-geographic barrier that separates the semi-arid north from the sub-tropical south and defines northern and southern Paleolithic industries. Although evidence suggests models associated with the Qinling Mountains need refinement, our results demonstrate that there are observable differences between the southern and northern Qinling Mountains and are in good agreement with previous observations. Here, we use the carbon isotopic values (δ13C) of leaf wax lipids to reconstruct the ratio of C3 to C4 vegetation at long-term Pleistocene Homo erectus occupations of the Hanzhong and Luonan Basins of the Eastern Qinling Mountains. In Hanzhong, isotopic range is low (1.5‰) and vegetation was dominated by C3 vegetation (85–90%) throughout the middle to late Pleistocene. Paleolithic technologies associated with these stable vegetation regimes are dominated by expedient Mode I technologies throughout the entire record. Conversely, in Luonan, isotopic range is significantly higher (4.2‰) and C4 vegetation increases to approximately 40% during some periods, which represents the expansion of forest-grassland mosaics. These fluctuating vegetation regimes are also associated with the emergence of Mode II bifacial technology, suggesting variable environments triggered the need for multifunctional handaxe technology. Our research demonstrates that there are key differences between the southern and northern Qinling Mountains, and that the northern Qinling Mountains are associated with both forest-grassland mosaics and less expedient technologies. Finally, in both basins our records demonstrate that patterns in C3:C4 track Marine Isotope Stages and appear to operate on interglacial-glacial timescales.

Overview of the Fundamentals and Applications of Bifacial Photovoltaic Technology: Agrivoltaics and Aquavoltaics

Bifacial technology is attracting the attention of the photovoltaic community. Although considered premature, research and development activities still need to be carried out to improve bPV performance. In addition, the need for a standard test reference will aid bankability and increase confidence in this technology. This article describes the state of the art of bifacial technology, going through the bPV cell and its difference compared to conventional monofacial cells and listing the different sources of limitations, with an identification of different parameters that characterize the performance of the bifacial. Then, the paper reviews the different modeling methods that allow predicting the performance of bPV systems, and ends with the most important applications, whether for dual use of land to produce energy and food (agrivoltaic) or for placing bPV modules on water bodies instead of on the ground (aquavoltaics), or for vertical use as solar fences, acoustic barriers, or building-integrated photovoltaic modules.

Current-matching erases the anticipated performance gain of next-generation two-terminal Perovskite-Si tandem solar farms

The bifacial gain of various optimally-tilted, and tracking bifacial farms based on single-junction PERC and HIT technologies are well established. The solar module technology is, however, evolving rapidly with the commercial development of two, three, and four-terminal mono and bifacial HIT-Perovskite tandem cells underway. Given the complexity of current-matching in two-terminal tandem cells and significant variation of the weather conditions across the world, one wonders if the benefits of fixed-tilt and tracking cells obtained for single-junction solar cells would remain for tandem solar cells. In this paper, we use a detailed illumination and temperature-dependent bifacial solar farm model (supported by a detailed physical model for bifacial HIT-Perovskite tandem cells) to show that (a) row-to-row shading in solar arrays significantly suppresses the effective albedo collection and thereby the two-terminal (2T) tandem cell efficiency and relative gain compared to an optimal bifacial HIT cell, (b) the global energy yield potential of fixed-tilted and solar-tracking topologies would improve by adopting a 2T tandem design at optimal albedo, with maximum gain arising for tracking farms, (c) the 2T tandem cell/modules (subcell bandgaps, thickness) must be optimized for maximum benefit, and (d) even a relatively small deviation from the optimum will negate all benefits. Our results will broaden the scope and understanding of the emerging tandem bifacial technology by demonstrating global trends in energy gain for worldwide deployment and the need for location-specific tailoring of the module design.

Feasibility Assessment of Bifacial Rooftop Photovoltaic Systems in the State of Gujarat in India

Bifacial solar photovoltaic (PV) modules are one of the recent interventions in the widespread commercial deployment of solar energy. This study intends to analyze the adoption of bifacial solar panels in rooftop PV systems to enhance energy generation as compared to their mono-facial counterparts. The technical and economic advantages of a typical 5-kW single-phase solar rooftop photovoltaic system using bifacial Si-modules are presented and compared with those using traditional polycrystalline Si (poly c-Si) modules in the urban location of the state of Gujarat in India. This methodology allows one to find optimal performance under the same irradiation and load conditions. As the majority of terraces in this location have a surface of white or gray tiles, which have a high albedo factor, bifacial modules generate more than 10% excess energy as compared to the poly c-Si systems. Although bifacial modules have an initial cost higher than the polycrystalline counterparts, the cost of their balance of system and space is reduced by 2 to 13%, respectively. Analysis shows that a 5kW bifacial technology can generate an excess of 13 MWh as compared to the traditional poly-Si over a period of 25 years. Finally, it is seen that an optimized bifacial system that is tilted between 15 and 20° will reduce the levelized cost of electricity (LCOE) by 5.5% as compared to the traditional poly c-Si system.

«Тонкие» листовидные бифасы начала верхнего палеолита Алтая: технология, формообразование и каменное сырье

The tradition of producing bifacial leafshaped points in Altai demonstrates a relationship with the culture and life support strategies of its earliest Upper Palaeolithic inhabitants. Here we present the reconstruction of bifacial technologies, based on the study of published data and archaeological collections, the latest results of geological and mineralogical data and experiments. The application of the well-known techniques of processing thin flint bifaces characteristic of the Russian Plain to the raw materials of Altai and to the local canons of producing bifacial tools makes it possible to reveal a number of factors that have a considerable effect on the morphology of the bifacial end products. We concluded that the transition from the massive Middle Palaeolithic bifaces to the thin and symmetrical leafshaped forms of the Initial and Early Upper Palaeolithic was associated with changes in stone processing. We found that the peculiarities of the Altai raw materials with their specific consumer characteristics and a high level of petrographic diversity did not exert much influence on the techniques of biface manufacture, but had a profoiund effect on the process of secondary thinning. As a result, the finished products turned out to be more massive than those made of flint. The results of the study confirm the need for a flexible approach to understanding the term «thin» biface.

Study of energy improvement with the insertion of bifacial modules and solar trackers in photovoltaic installations in Brazil

To improve the performance of photovoltaic systems, solar trackers have been widely used in photovoltaic power plants. Recently, bifacial modules also have started being widely used in the photovoltaic market for the same purpose. Bifacial technology is currently being widely discussed by the scientific community due to the considerable challenges and possibilities, such as modelling and mismatch of irradiance on the rear side of the module, albedo databases, optimum orientation and heights, and the meagre amount of measurement and study data for specific locations. This work presents and compares simulation results of a photovoltaic plant with monofacial and bifacial modules installed on a fixed structure and solar trackers in seven localities in Brazil. Bifacial gains, tracker gains, and bifacial-tracker gains were calculated and compared for each location. A comparison of system gains was also made by varying ground coverage ratio and clearance height in two locations. The results showed that the bifacial gain varies from 3.78% to 8.16%, and the tracker gain varies from 13.40% and 18.20% depending on weather conditions and system configuration. The total gain from the application of bifacial modules and trackers varies between 19.39% and 27.39%. Therefore, the potential of combining these technologies to enhance the technical and economic viability of photovoltaic plants is emphasised.

Middle Stone Age Bifacial Technology and Pressure Flaking at the MIS 3 Site of Toumboura III, Eastern Senegal

Over the past decade, the increasing wealth of new archaeological data on the Middle Stone Age (MSA) in Senegal and Mali has broadened our understanding of West Africa’s contributions to cultural developments. Within the West African sequence, the phase of Marine Isotope Stage 3 (MIS 3, ca. 59-24 ka) yielded so far the best known and extensive archaeological information. The site of Toumboura III encompasses an occupation dated by optically stimulated luminescence (OSL) to between 40 ± 3 ka and 30 ± 3 ka. It provides the largest, well-dated, and stratified lithic assemblage in West Africa for the MSA and sheds light on an unprecedented cultural expression for this period, adding to the notable diversity of the late MSA in this region. We conducted a technological analysis of the lithic components following the chaîne opératoire approach. The lithic assemblage features a prevalence of bifacial technology and the exploitation of flakes as blanks for tool production. The craftspeople manufactured distinct types of bifacial tools, including small bifacial points shaped by pressure technique. The new data from Toumboura III demonstrate behavioral patterns that are entirely new in the region. By revealing behavioral innovations and technological particularities, these results on the techno-cultural dynamics during the MIS 3 phase of the MSA enhance our understanding of the complex Pleistocene population history in this part of Africa.

New morpho-technological studies to enhance the knowledge of Fell point variability in southeastern South America

In the wide field of archaeology, stone tools are one of the major pieces of evidence to assess the knowledge and understanding of the peopling of the Americas. To answer anthropological questions concerning migration routes, colonization events, and further socio-cultural developments in the Americas, long term research has been directed to deepening the knowledge and understanding diverse technological topics of terminal Pleistocene/Early Holocene lithic remains, with particular focus on “fishtail”, “Fell’s cave”, or just “Fell” projectile points. Resulting from the research advances, this paper provides further detailed information to enlarge the database and morpho-technological knowledge of Fell points from north of the La Plata River, in the southern cone of South America. The analyzed sample has shown that there is broad technical and dimensional variability. Based on specific technological features and well-dated coeval finds, with some caution I consider the hypothesis that in certain places, the Fell points makers might have developed a regional variant with barbs or highly acute shoulders. The new observations have significant implications for understanding one of the earliest bifacial technologies in the archaeology of the Americas.

Origine des différentes traditions culturelles au Paléolithique supérieur ancien en Europe Centrale

In the early phase of the Upper Palaeolithic the cultural traditions that were expressed in lithic technology, way of life, also in various elements of symbolic culture had a complex nature. They can be divided in terms of derivation, occupied territory, chronology, and – partially – the anthropological type of a given population. The traditions whose origins were local were in all likelihood related to the Neanderthals, whereas those whose origins were exogeneous were connected with Anatomically Modern Humans. In terms of technologal-stylistics in the initial phase of the Upper Palaeolithic, we can distinguish autochthonous traditions rooted in a local Levallois or Moustero-Levallois substratum, traditions developped from a local Micoquian substratum with bifacial technology, and traditions rooted in the industries with blade and bifacial technologies of the Middle Palaeolithic. These are opposed to allochtonous traditions that can be related to the migrations of Anatomically Modern Humans from the Near East.

Pezmogty 3B – a small Neolithic dwelling on the Middle Vychegda (Komi Republic)

The paper publishes the results of a study of complex B of Pezmogty 3 site. The author has studied traces and remains of a depressed small dwelling with an excavation area of 81 m. The spatial distribution of artefacts, faunal remains and their association with deposits of different genesis have been analysed. It is defined that the studied structure was rounded in the plan, 3,03,5 m in diameter, 79,5 m in area, and, probably, a cone-shaped roof. The assemblage contains stone objects, fragments of ceramic ware and indeterminable items, fragments of calcified bones. The morphology of the flint arrowheads; the signs of secondary bifacial thinning technology; the ceramic pots, made of clay with an admixture of silt and decorated with a comb-pit ornament, allow us to attribute these materials to the Lyalovo culture in the European North-East and date them to the first half of the V millennium B.C. Until now, the most informative data for the study of this culture in north-eastern Europe were the remains of medium and large dwellings with an area of 26 to 100 m, so the published materials expand our understanding of the way of life and house-building traditions of the Middle Neolithic people of this region.

Global analysis of next-generation utility-scale PV: Tracking bifacial solar farms

The bifacial gain of East-West vertical and South-facing optimally-tilted bifacial solar farms are well established. One wonders if bifacial gain and the associated levelized cost of energy (LCOE) may be further improved by tracking the sun. Tracking bifacial photovoltaics (PV) system has advantages of improved temperature sensitivity, enhanced diffuse and albedo light collection, flattened energy-output, and reduced soiling. Monofacial tracking already provides many of these advantages, therefore the relative merits of bifacial tracking are not obvious. In this paper, we use a detailed illumination and temperature-dependent bifacial solar farm model to show that bifacial tracking PV delivers up to 45% energy gain when compared to fixed-tilt bifacial PV near the equator, and ~10% bifacial energy gain over tracking monofacial farm with an albedo of 0.5. An optimum pitch further improves the gain of a tracking bifacial farm. Our results will broaden the scope and understanding of bifacial technology by demonstrating global trends in energy gain for worldwide deployment.