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• Policies and incentives are needed to trigger the adoption of ESS. • The proposed LCOS equation considers the hourly energy flow and ToU tariffs. • PV systems alone are the most profitable investment for residential costumers. • ToU tariffs and CAPEX are the main factors affecting rentability of PV + ESS systems. • ESS alone are not currently cost-competitive with PV alone or PV + ESS. Power distribution grids all over the world are experiencing exponential growth in the number of distributed generators (DG), especially for small-scale, residential, and commercial rooftop photovoltaic (PV) systems. Electrical energy storage systems (ESS) allow for the decoupling of generation from consumption, addressing the issue of PV supply intermittency in the traditional electricity grid, and improving the potential penetration and widespread deployment of PV on the distribution grid. Several articles were reviewed to list and better understand the different variables that influence the technical and economic evaluation of a PV + ESS system. By proposing and applying a novel hybrid Levelized Cost of Storage (LCOS) analysis, the effects of adopting ESS in the Brazilian regulatory framework were evaluated. The proposed method is universal, and the Brazilian case study is presented to illustrate it. Results are compared with an alternative of PV-only systems in a flat tariff scheme and show that a sharp drop in ESS initial costs is required before PV systems plus storage become the best investment alternative for the end user. However, the PV + ESS alternative results in a positive impact for the whole grid, suggesting that policies towards cost reductions and incentives, such as a wider Time-of Use tariff spread, should be designed to stimulate the adoption of ESS associated with DG solar PV. [ABSTRACT FROM AUTHOR]

• New findings about the optimization of perovskite solar cells by multidimensional numerical optimizations. • Design proposals which increase the efficiency of the state-of-the-art manufactured and simulated cells. • Highest efficiencies in perovskite cells with light trapping for a large range of absorber layer thicknesses. • Maximum efficiencies by light trapping and material property improvements. • 2.5-fold toxicity reduction. To obtain significant increases in the Power Conversion Efficiency (PCE) of solar cells, we argue that the substitution of the state-of-the-art one- and two-dimensional cell optimizations, by the simultaneous improvement of multiple material properties is of substantial advantage. In this context, researchers should know, which combined material properties and cell design parameters result in the highest efficiency increase. For the same objective, it is also of importance to know, which ideal relationships in-between these variables have to be adjusted. Such knowledge becomes available by simulations and numerical optimizations, which we present for a Perovskite Solar Cell (PSC) in a hypercube space of model variables. We prove that its PCE increases principally because of the nonlinearities inherent to its mathematical model, and therefore, we elucidate the importance of the multidimensional variable improvements in the PSC's optimization. We increased the PCE to a value of at least 27.6% by simultaneous improvements of the cell's material properties, and light trapping, for a large range of absorber layer thicknesses, from t 0 = 160 to 400 nm. The lower thickness results in a significant reduction of the device's Pb content. [ABSTRACT FROM AUTHOR]

Abstract This work assesses the electricity consumption profile of domestic solar hot water systems (DSHWS) and analyses, at high measurement-time resolutions for the first time, their economic viability in popular housing projects in Brazil. It analyses the impacts of the active power demand measurement-time resolution on the financial attractiveness of DSHWS. The predominance of a late-evening profile of electricity consumption for showering, coinciding with distribution utilities' peak demand hours, leads to over 40% avoided active power during peak hours per consumer unit when adopting DSHWS. There is potential to finance DSHWS in popular housing with very favourable conditions for the distribution utility. For discount rates ranging from 0 to 9.5%, payback times ranged between less than four and five years, NPV between $ 2,191 and $ 782, and IRR between 25% and 14%. The measurement of power demand at 15-min intervals, widely adopted by distribution utilities, is not adequate to properly evaluate the financial attractiveness of DSHWS, resulting in pessimistic financial analyses of the return on investment. The low load-factor of electric showerheads used in >90% of Brazilian households, leads to the accounting of only 37% of the real avoided cost of adopting DSHWS when measuring power demand in 15-min intervals. Highlights • Demand measurement time resolution has strong impact on the economics of DSHWS. • Benefits of DSHWS cannot be fully assessed at 15-min measurement-time resolution. • 15-min measurement-time resolution leads to accounting of <40% of DSHWS benefits. • Only 1-min measurement-time resolution reveals full benefits of solar water heating. • Subsidised tariffs for low-income dwellings make DSHWS attractive to the utility. [ABSTRACT FROM AUTHOR]

Highlights • Electricity consumption in Brazil will grow 3.9% annually from 2017 until 2024. • Brazil's northeast houses the majority of projects contracted in the energy auctions. • Around 28% of annual irradiation was at irradiance levels at or above 1000 W/m2. • PV modules cost reductions led to higher inverter loading ratios in system design. • A methodology was developed for estimating the optimal inverter sizing in the region. Abstract This study is aimed at performing and analyzing the inverter sizing optimization process for large-scale grid-connected solar photovoltaics (PV). The local solar resource was evaluated and compared to the available satellite data. Analyses of the solar irradiance distribution and its potential effects on inverter sizing were performed. The performance of five different, commercially-available PV module technologies was also evaluated by means of remote data analysis of irradiation and temperature, as well as electrical parameters. This was performed using the metrics of energy yield and performance ratio (PR) for PV systems. A methodology was developed for estimating the optimal inverter sizing in the region considering overload losses and economic aspects, aiming at the optimization and cost reduction of PV-generated electricity. Considering the five technologies, the mean yield was 150 kWh/kWp on a monthly basis. The annual PR ranged from 77% to 85% depending on technology. The local solar resource, measured during three years, was compared to five distinct satellite-derived solar databases. Cloud enhancement and cloud edge effects were observed through the monthly solar irradiation distribution over the three years of measurements. Around 28% of the incident annual irradiation was at irradiance levels at or above 1000 W/m2. The methodology developed for the optimal inverter loading ratio (ILR) was applied over one full year of solar generation data for the five technologies. It was observed that for inverter loading ratios commonly used on utility-scale PV power plants (around 120%), the overload losses varied from 0.3% to 2.4%, depending on technology. The optimal ILR for the more traditional crystalline Si PV technology was estimated to be 126%. [ABSTRACT FROM AUTHOR]

This work presents a method to evaluate, from the distribution utility's perspective, the impacts of adopting Domestic Solar Water Heating (DSWH) systems in Brazil, based on demand measurements carried out on two groups of residential households. For the 12 months period evaluated, the case-study shows that using DSWH results in savings of 198 kWh (38%), and active power demand savings at peak times of 860 W (42%) per individual unit. For the distribution utility and per individual unit, using DSWH leads to avoided costs of $ 27.59 (38%), avoided costs due to peak time demand reduction of $ 170.2 (42%), and annual avoided costs of $ 197.79 (41%). This work clearly shows that in the residential section the tariff model and structure is strongly distorted, since it only accounts for the energy consumption per residential unit, and completely disregards the costs associated with power demand availability. Our results show that in Brazil the distribution utility charges only some 15% of the real cost of a hot shower based on electric showerheads. [ABSTRACT FROM AUTHOR]

This paper proposes a simplified method to determine an index to quantify the influence of partial shadings on the performance of BIPV systems based on the relation between the shading percentages and the reduction of the incident irradiation on a given surface. The research is divided in two papers: Part 1: Theoretical study and Part 2: Application in case studies. Part 1 consists in identifying and quantifying the shading on a surface, and relates the fraction of shaded area with the percentage of incident irradiation reduction during the same period, in order to propose a shading index (SI) that represents the energy losses due to shadings on PV systems. The method was developed for a theoretical shaded case study simulated in two cities located at low latitude, tropical regions: Singapore (1.35°N) and Florianópolis-Brazil (27.48°S). Results showed that the shading percentage on the analysed surface on an annual basis is closer to the percentage of incident irradiation reduction at same period than when these values are compared on other time bases, as hourly, daily or monthly. Therefore, in this case, the annual percentage of shading can be adopted as the SI. SI was validated using different computer software packages and it was proved to be a convenient way of estimation the PV generation of similar cases of partially shaded PV systems, that could be used even before the PV electrical desing has been done. [ABSTRACT FROM AUTHOR]

This is the second part of the paper “Simplified method for shading-loss analysis in BIPV systems”. The objective of Part 2 is to apply the simplified method described in Part 1 in order to estimate the influence of partial shadings on the performance of four installed and in operation BIPV systems. The method consists in identifying and quantifying the shading on a surface, relating the fraction of shaded area with the percentage of incident irradiation reduction during the same period, in order to propose a shading index (SI) that represents the energy losses on partially shaded PV systems. SI was validated through the analysed case studies and it was proved to be a convenient way of estimating the PV generation of partially shaded PV systems. This method is independent from the electric configuration and can be used for already installed PV systems, or surfaces under investigation for PV installations, both through manual calculations and also through calculations using dedicated software packages. [ABSTRACT FROM AUTHOR]

The electrical resistance showerhead is the water heating technology used in over 70% of the Brazilian dwellings. These high power (5–8 kW are typical) instant heating devices contribute significantly to the demand peak in the early evening, and are a major burden to distribution utilities in Brazil. The objective of this paper is to define consumer showering patterns, and analyze the influence of the power demand measurement time resolution on the potential of peak time power demand reduction provided by Domestic Solar Hot Water (DSHW) systems. Results show that the measurement of electrical power demand in a 15-min interval is not adequate to evaluate and verify the benefits provided by the use of DSHW systems, because it heavily underestimates the active power demand reduction at peak hours. This work suggests that a 1-min time resolution can be considered appropriate to assess the potential impacts caused by the use of DSHW systems on the peak hours demand reduction. [ABSTRACT FROM AUTHOR]

The Brazilian territory is irradiated with solar energy ranging from 1500 to 2300 kWh/m 2 /year, compared to 900 to 1850 kWh/m 2 /year in Germany, France, Italy and Spain. Despite that, photovoltaic (PV) technology is only now starting to penetrate the Brazilian electricity mix. Until recently, the high costs of PV generation had prevented this technology from competing in Brazil. However, the consistent PV price reductions and the worldwide scale reached, has brought attention to the Brazilian planners and actions have been taken recently in Brazil to help PV start its progress. In this paper, two of the recent government actions are analyzed, namely the National Electrical Energy Agency ANEEL Resolution RN482/2012, and the announcement of support by the Brazilian Development Bank offering loans at low interest rates for solar PV projects. The effects of these actions for residential PV systems are positive where the conventional electricity tariff is high with respect to the average in the country, and less relevant elsewhere. We compare these tariffs with the calculated Levelized Cost of Energy of rooftop PV generation. The influence of these policies on the return on investment of residential rooftop PV generation is studied for different climatic zones in Brazil. [ABSTRACT FROM AUTHOR]

Abstract: Photovoltaic (PV) generation depends directly on the amount of radiation received by solar modules at a given temperature, and annual irradiation varies according to site location and PV array position. In this paper, the limitations and the solar irradiation levels received by building surfaces in different positions (with azimuth and tilt angle variation) in capital cities in Brazil are shown, making use of the Brazilian global horizontal solar irradiation data provided by the SWERA (Solar and Wind Energy Resource Assessment) project. These data were processed to generate figures on the irradiation at various PV module orientations and slopes for each city, which show the relative radiation levels received on specific azimuth and tilt angles in relation to the ideal position. Results were validated using four real and operating PV systems. In general, variations in azimuth or slope did not cause large annual irradiation losses up to around 20° tilt angles. This shows to PV system planners that under these fairly flexible conditions it is possible to install PV on any orientation, keeping high levels of annual irradiation, and that limitations in orientation and tilt can be relatively low. It also allows a quick analysis of PV retrofit in building-applied photovoltaics (BAPV), when seeking the best building surfaces to incorporate PV. [Copyright &y& Elsevier]

Abstract: Domestic solar hot water systems (DSHWS) have been used worldwide for many decades. Activities in this area are usually targeting middle- or upper-class residential dwellings, and solar collector design and sizing is carried out aiming at this market. In developing countries of the sunbelt, however, there is a huge potential for low-cost DSHWS in low-income residential dwellings. We have assessed the technical and economic viability of this technology, both from the electric utility''s perspective, and from the standpoint of low-income residential consumers. We have analysed data of 12 months of continuous monitoring of a statistically representative sample of consumers at a low-income residential building in Florianopolis – Brazil (27°S, 1550 kWh/m2/year solar irradiation average). We have studied the power consumption of 60 residential units equipped with a commercially available, low-cost DSHWS, and a 30 units control group, where hot water was supplied with the electronic showerhead typical of Brazilian dwellings. Annual electricity savings averaged 38%, and peak-time electricity demand was reduced by 42%. For discount rates of up to 9.5%, this technology is attractive from a utility''s perspective for large-scale deployment. The financial benefit from avoided CO2 emissions has limited economic attractiveness, and can only be justified under a large-scale deployment program. [Copyright &y& Elsevier]

Abstract: The integration of solar modules on buildings’ roofs and façades is one of the most elegant applications of photovoltaics (PV). With the declining costs of this technology, building-integrated and building-applied photovoltaics (BIPV and BAPV) can efficiently and cost-competitively assist in delivering electricity in urban environments. We have quantified the potential of BIPV and BAPV generators on existing single-family detached residential buildings in Florianopolis–Brazil (latitude 27°S, solar irradiation 1550kWh/m2/year), in supplying each house and a fraction of the local utility feeder''s electricity demands. We have measured and compared the annual output performance of thin-film amorphous silicon, and traditional crystalline silicon solar PV technologies, and proposed solar PV kits to be installed on all of the existing 496 residential buildings roof tops in the mixed residential–commercial area studied. The typical single-family, detached home roof covers can easily accommodate the proposed PV kits, with 87% of these generators yielding at least 95% of the maximum theoretical generation output of an ideally oriented and tilted PV system. Low-pitched, existing roof covers in residential houses represent excellent areas for PV integration at low latitudes. Installing BIPV on all of the available roof areas can make each and every house a net energy-positive building. [Copyright &y& Elsevier]

Abstract: In Brazilian low-income households, water-heating requirements are typically met by electrical showerheads. On average, 73.1% of all residential units in the country are equipped with these resistance-heating devices, with nominal powers ranging from 3 to 8kW. This situation imposes a considerable burden on the electricity utility companies, since electrical showerheads typically represent the highest load but the lowest utilization (load factor) in a residential consumer unit. Furthermore, typical utilization times coincide with, and contribute to, the electrical power demand peaks in Brazil, rendering these low-cost, high-power electrical devices a high-cost consumer for the electrical system to cater for. For low-income residential consumers, electricity tariffs are subsidized, and utilities must therefore make a considerable investment in infrastructure for a limited return. In this paper we analyze the impacts of solar water heating in low-income households on the distribution utility active, reactive and apparent power demands. We have monitored a statistically representative group of low-income residences equipped with a compact domestic solar water heater in Florianopolis – Brazil for 1year. We show that in comparison with identical residential units using electrical showerheads, with the adoption of solar water heating the reductions in the active, reactive and apparent power demands on the distribution utility were 49%, 29% and 49% respectively. [Copyright &y& Elsevier]

Abstract: Especially in warm climates, a considerable fraction of the electricity demand in commercial buildings is due to the intensive use of air-conditioning systems. Airport buildings in sunny and warm regions present a perfect match between energy demand and solar resource availability. Airport buildings are also typically large and horizontal, isolated and free of shading, and have a great potential for the integration of solar photovoltaic (PV) systems. In this work, we assess the potential impact in energy demand reduction at the Florianopolis International Airport in Brazil (27°S, 48°W) with the use of building-integrated photovoltaic (BIPV) systems. We analyse the building’s hourly energy consumption and solar irradiation data, to assess the match between energy demand and potential generation, and we estimate the PV power necessary to supply both the total amount and fractions of the annual energy demand. Our results show that the integration of PV systems on airport buildings in warm climates can supply the entire electric power consumption of an airport complex, in line with the general concept of a zero-energy building (ZEB). [Copyright &y& Elsevier]

Abstract: Because of the intermittent nature of the solar radiation resource, photovoltaic (PV) solar energy generation is considered a non-dispatchable power source. However, under some conditions, in sunny urban areas with electricity load curves dominated by air conditioning loads, there is a high correlation between PV generation and utility feeder loads. In these situations, a considerable fraction of a given PV generator can be considered dispatchable power. In this work, we assess the potential of grid connected, building integrated photovoltaic (BIPV) generation in the state capital, Florianópolis, in south Brazil (27°S, 48°W), which is supplied by the local utility company through 56 feeders. Our interest was to identify which feeder could obtain more benefits with implementation of a PV plant with a specific nominal power. Two factors are important in this analysis: the peak demand reduction value, and the LOLP (loss of load probability, in failures per year), or LOLE (loss of load expectation, in hours per year). We analyzed the hourly demand curves of the 56 feeders and compared them with the PV power generation values obtained from a 2kWp BIPV installation that has been operating continuously for nearly 10 years connected to one of these feeders. For our calculations, we defined a PV installation of 1000kWpAC, which corresponds to penetration level values between 10% and 20%, depending on the specific feeder considered. Our results demonstrate that the use of PV power plants can reduce significantly the summer demand peaks in regions where the load reflects commercial customers demand for midday air conditioning. [Copyright &y& Elsevier]

Abstract: Building-integrated photovoltaic (BIPV) generators are typically small and distributed solar power plants that occupy virtually no space because they are part of the building envelope, and they generate power at point of use. A more widespread use of grid-connected photovoltaics (PV) is hindered by a number of reasons which include the declining, but still high costs of the photogenerated kilowatt hour, and the lack of knowledge about the benefits of distributed generation with PV in the urban environment. When strategically sited, PV generators integrated to building façades and rooftops in urban areas at limited penetration levels can benefit local feeders with these distributed “negative loads”. A number of studies have been published, with learning curves demonstrating the cost-reduction potential of large-scale PV production, and in some markets the cost of PV electricity is approaching residential tariffs, the so-called grid parity. Due to the intermittent nature of the solar radiation resource, PV is considered non-despatchable power, but under some conditions, in sunny urban areas with electricity load curves dominated by air-conditioning loads, there is a high correlation between PV generation and feeder loads. In these situations, a considerable fraction of a given PV generator can be considered despatchable power. In this work we assess the potential of building-integrated, grid-connected PV generation in the state capital Florianópolis, in South Brazil. The deployment of six different commercially available PV technologies is compared with total roof area availability, solar generation profiles, and local feeder load curves for a selected number of urban areas in the city. Our results demonstrate the advantages of strategically siting PV generators in the urban environment. [Copyright &y& Elsevier]

Abstract: Inverter sizing strategies for grid-connected photovoltaic (PV) systems often do not take into account site-dependent peculiarities of ambient temperature, inverter operating temperature and solar irradiation distribution characteristics. The operating temperature affects PV modules and inverters in different ways and PV systems will hardly ever have a DC output equal to or above their STC-rated nominal power. Inverters are usually sized with a nominal AC output power some 30% (sometimes even more) below the PV array nominal power. In this paper, we show that this practice might lead to considerable energy losses, especially in the case of PV technologies with high temperature coefficients of power operating at sites with cold climates and of PV technologies with low temperature coefficients of power operating at sites with warm climates and an energy distribution of sunlight shifted to higher irradiation levels. In energy markets where PV kWh’s are paid premium tariffs, like in Germany, energy yield optimization might result in a favorable payback of the extra capital invested in a larger inverter. This paper discusses how the time resolution of solar radiation data influences the correct sizing of PV plants. We demonstrate that using instant (10s) irradiation values instead of average hourly irradiation values leads to considerable differences in optimum inverter sizing. When calculating inverter yearly efficiency values using both, hourly averages and 1-min averages, we can show that with increased time resolution of solar irradiation data there are higher calculated losses due to inverter undersizing. This reveals that hourly averages hide important irradiation peaks that need to be considered. We performed these calculations for data sets from pyranometer readings from Freiburg (48°N, Germany) and Florianopolis (27°S, Brazil) to further show the peculiarities of the site-dependent distribution of irradiation levels and its effects on inverter sizing. [Copyright &y& Elsevier]

The outdoor operation and monitoring of amorphous silicon (a-Si) solar modules present unique features when compared to the more traditional and quite well understood operation of the crystalline silicon (c-Si) technology. The peculiarities of a-Si contrast to such extent with those of c-Si solar cells that in the field, while the former performs better during summer, the latter is more efficient in winter. Concepts usually applied to describe phenomena in c-Si devices are often inadequate to describe the performance of a-Si cells. When looking at module performance, the fill factor (FF) can be regarded as one of the characteristic photovoltaic quantities of major interest. Under outdoor illumination, cells are seasonally exposed to different solar spectral contents and intensities, which vary considerably from summer to winter. The FF depends on both the quality (spectrum) and quantity (irradiation) of the incident light. In this context, we report results showing spectral effects on the FF of amorphous silicon solar modules deployed outdoors. While "blue" spectra improved the FF of a-Si devices, the contrary was observed for "red" spectra. The voltage-dependent spectral response of a-Si devices is also described and quantified. Our results reveal that a-Si modules can perform quite well at low irradiations and mainly diffuse spectra. We, thus, conclude that in system sizing programmes, the performance of a-Si modules should be treated more precisely with respect to spectra, to reveal their true operational characteristics and advantages. [ABSTRACT FROM AUTHOR]

In recent years, aerial infrared thermography (aIRT), as a cost-efficient inspection method, has been demonstrated to be a reliable technique for failure detection in photovoltaic (PV) systems. This method aims to quickly perform a comprehensive monitoring of PV power plants, from the commissioning phase through its entire operational lifetime. This paper provides a review of reported methods in the literature for automating different tasks of the aIRT framework for PV system inspection. The related studies were reviewed for digital image processing (DIP), classification and deep learning techniques. Most of these studies were focused on autonomous fault detection and classification of PV plants using visual, IRT and aIRT images with accuracies up to 90%. On the other hand, only a few studies explored the automation of other parts of the procedure of aIRT, such as the optimal path planning, the orthomosaicking of the acquired images and the detection of soiling over the modules. Algorithms for the detection and segmentation of PV modules achieved a maximum F1 score (harmonic mean of precision and recall) of 98.4%. The accuracy, robustness and generalization of the developed algorithms are still the main issues of these studies, especially when dealing with more classes of faults and the inspection of large-scale PV plants. Therefore, the autonomous procedure and classification task must still be explored to enhance the performance and applicability of the aIRT method. [ABSTRACT FROM AUTHOR]

• The five most widely used solar radiation databases were reviewed and compared. • The two most popular PV system sizing software tools were compared. • Hundreds of isolated minigrids in the Amazon are supplied by diesel gen sets with precarious diesel supply. • Combinations of solar radiation database and PV system simulation tools were compared. • Differences in PV sizing and energy generation amounted to over 20% for the same diesel minigrid. • Differences are much more due to solar radiation database than to simulation software. This study evaluated the outcome differences when adopting five different solar irradiation databases on the sizing of hybrid solar photovoltaic-diesel generators designed to supply electricity to isolated minigrids. To do this, the two most widely adopted photovoltaic (PV) simulation packages in the market, namely PVsyst® and HOMER Energy® were used. The different origins, data timespan, space and time resolution, of the five most relevant solar irradiation databases available for the region were compared. A case study was presented to illustrate the influences of the solar irradiation database and the solar simulation tool on the resulting PV generator. Furthermore, the hourly behavior of the energy supply to an existing load in a minigrid in the Brazilian Amazon was evaluated, together with the savings in diesel obtained with the resulting PV generator. Evaluating the five options of solar radiation databases, for the same PV plant configuration, variations of up to 19.7% were found in the expectation of PV generation. When the simulation software package was varied, the combined effect (radiation database X PV system sizing tool) showed differences of up to 20.6%. This demonstrates that despite having different algorithms, computational tools have a small influence (less than 1%) on results. These combined differences, taking into account the load curve behavior and the total diesel generation capacity installed at the site, resulted in over 100% differences in the optimum PV generator size in the case study. The total savings in diesel fuel, over a 15-years period, ranged from $ 6.5 million to over $ 16 million (>2.5 times) for the smallest PV system. This demonstrates the importance of the correct choice of database. These evaluations can be extended to minigrids of any size elsewhere. The novelty and originality of this study is to demonstrate and quantify for the first time the influence of the solar radiation database and the PV simulator package on the sizing of PV-diesel generators. The consequences of this study are not only of scientific and academic importance, but of economic and commercial interest as well. [ABSTRACT FROM AUTHOR]

• Proposed method to evaluate PV + BESS economic landscape for brazilian dwellings. • Positive impact of adopting a BESS in the PU from the energy perspective. • BESS costs impact economic viability and need government incentive. • Method can be adapted to other scenarios. This paper proposes a methodology to assess the energy and economic impact of adopting small-scale residential photovoltaic (PV) systems paired with lithium-ion battery energy storage (BESS) systems in single-family homes, under the current energy feed-in legislation. The suggested methodology was applied to a case study of a prosumer unit (PU) in Brazil. Data from energy bills, measured PV generation, BESS behaviour, and energy consumption were analysed to compare different viewpoints and estimate key economic indicators. As a result, the PV + BESS combination increases residential users' energy self-consumption and self-sufficiency, resulting in respective increases of 15 % and 2 %. Under the conventional tariff, adopting the PV + BESS system led to an average 29 % reduction in electricity costs compared to scenarios without PV + BESS. Furthermore, by transitioning to the white tariff mode in conjunction with PV + BESS, the PU achieved a 49 % reduction. This result emphasizes the advantages of time-of-use adoption for PV + BESS consumers. A greater discrepancy between tariff periods enhances the feasibility of storing off-peak energy for use during peak periods. Currently, BESS implementation costs impede competitiveness, with attractive LCOS metrics achieved only at costs below $600.00/kWh and MRAs below 9 %. BESS + PV lowers generation costs compared to off-peak rates, increasing the viability of shared usage. Integrating PV + BESS systems with rate switching significantly diminishes electricity expenses. The substantial BESS implementation cost necessitates a noteworthy rate differential for viability, which could potentially impact non-PV and non-BESS consumers. [ABSTRACT FROM AUTHOR]

• aIRT equipment equipped with a RGB camera improves inspection. • Post-flight image analysis provides a faster aIRT inspection. • The most common problem detected were hot spots caused by soiling and vegetation. • The most common defect in the power plants were disconnected cell substrings. • The defect with higher impact on the PV plant performance are disconnected strings. The uptime of utility-scale solar photovoltaic (PV) power plants is of utmost importance for meeting contractual energy yields and expected capacity factors. Aerial Infrared Thermography (aIRT) is a non-destructive, no-downtime, fast and cost-effective method for monitoring large-scale PV power plants and assisting in fault detection. The use of aIRT techniques aims at increasing the quality and service life of PV plants especially in sunny and developing countries such as Brazil, where there is a shortfall of specialised workforce and the costs for a detailed supervisory system of utility-scale PV power plants are high. This paper presents an analysis of an aIRT flight campaign over four utility-scale PV plants in the northeast of Brazil. Two types of measurement equipment have been tested and compared, resulting in more stability and efficiency using a commercially available solution. This solution was also equipped with a RGB camera that accelerated the inspections, since it helped to differentiate defects from hot spots caused by soiling and vegetation over the modules, which were common. Different methods for fault detection were also tested and it was concluded that post-flight image analysis provides faster results. The most common faults that can happen in the early operation of PV power plants and how operators should address and prevent them were also discussed. The most common defect detected during the campaign were disconnected cell substrings. However, disconnected strings had the most impact on the power plants energy performance. [ABSTRACT FROM AUTHOR]

• SMARTS + satellite method led to good results for field IV curve spectral correction. • CdTe showed spectral factors of up to 10% for Northern and 2% for Southern Brazil. • Average spectral factor for mc-Si in Florianópolis showed 2% spectral losses. • SMARTS + satellite data method yielded good irradiance-weighted averaged SF results. This paper presents an analysis of spectral impacts on mc-Si and new generation CdTe in two distinct regions of Brazil: Florianópolis-SC (27°S, 48°W) in the South, and Assu-RN (5°S, 37°W) in the Northeast. As utility-scale PV power plants are progressively being deployed in the Brazilian Northeast, the need for evaluation of the spectral effects of local blue-biased spectra on the energy yield of different PV technologies arises, as well as the need for spectral correction of field peak-power measurements done during commissioning and system performance tests. Considering the high cost of adequate spectral measurement equipment, this paper proposes a new approach for the estimation of spectral impacts without the need for in loco measurements. The proposed methodology consists of the use of satellite data acquired from NASA's Giovanni platform as inputs for the SMARTS 2.9.5 spectra model. Results for measured spectra showed that, for both locations, new generation CdTe (i.e. First Solar Series 4 and 6) has significant spectral gains: up to 10% for Assu-RN (Northeastern Brazil) and 2% for Florianópolis-SC (Southern Brazil). A seasonal variation could also be detected for the Florianópolis site, with lower spectral gains for CdTe - and higher for mc-Si - close to the Southern Hemisphere's winter solstice, due to higher air mass values and lower precipitable water content of the atmosphere. The proposed method using Giovanni data and SMARTS spectra modeling produced very similar spectra to those measured for clear days in the field at both sites, yielding good results for the calculation of spectral factors for both mc-Si and CdTe. For days with a higher diffuse fraction the results were not as satisfactory, as expected. The proposed method was also applied to instantaneous measurements for three different times (and AM values) of the day for Florianópolis: 9:00, 12:00 and 15:00, yielding satisfactory results for IV curve spectral correction. [ABSTRACT FROM AUTHOR]

Rooftop residential photovoltaic (PV) generation is becoming more widespread among homeowners. A proper PV system design is crucial in order to avoid annual electricity production in excess of residential demand in countries where a net metering scheme is in place like in Brazil. It is therefore important that the information related to the average solar irradiation incident on the solar modules is accurately assessed, allowing precise estimates of photovoltaic electricity production. This work defines the criteria for the proper choice of a freely available irradiation database for the Brazilian territory and compares the results with the PVsyst-Meteonorm, a well-known modeling system. We demonstrate that, for Brazil, the Global Horizontal Irradiance (GHI) information provided by Openei-SWERA series is the best fit to different locations in the Brazilian territory, after introducing the corrections made by the horizontal to the plane-of-array transposition algorithms. [ABSTRACT FROM AUTHOR]

• Development of a fault detection algorithm on aIRT images highlighting its main challenges, shortcomes, and workarounds; • Utilization of an orthomosaic reconstruction software package describing the challenges that the workflow impose for the automatic fault detection algorithms; • Evaluation of the impact of different flight configurations and dataset on the processing time and results; • Application of the proposed framework in real cases, evaluating the challenges imposed by real datasets. As large-scale Photovoltaic (PV) power plants are being expanded in installation number and capacity, aerial infrared thermography (aIRT) has proven to be effective in detecting at different phases of their development, construction and commissioning to operation and maintenance. However, evaluating the aerial imagery over hundreds of hectares fields of PV arrays is very time-consuming and subject to human error. This paper proposes a complete framework for automatically detecting faults in large-scale PV power plants and their physical location inside the plant site. To this end, a Mask-RCNN algorithm is developed and fine-tuned for instance segmentation using a dataset of 93 samples collected in an aIRT flight campaign in Brazil. The results are combined with orthomosaic techniques to create an orthomap of the PV system with the highlighted faults. The proposed method has been tested to automatically detect the faults in two power plants. Several tests were performed to improve the algorithm's accuracy, resulting in high-accuracy results for detecting and localizing hot spots in PV plants and disconnected substrings. The resulting maps could successfully show the location of these faults with high accuracy (10% of false positives). [ABSTRACT FROM AUTHOR]

The proposition of Net Plus-energy Buildings (NPEB) leads to the need to carry out studies of load matching in contrast with the grid impacts of distributed generation (DG). This paper performs simulations with the EnergyPlus software tool concerning a NPEB operating in four Brazilian metropolitan areas. The analyses include photovoltaic (PV) performance parameters and Load Matching and Grid Interaction indicators (LMGI). New grid impact indicators are defined in order to study the impacts of DG in the power grid. In the second stage, the work investigates economic aspects under net metering supporting. Results show the annual amount of electrical demand covered by PV varies from 29 to 51% with more potential in situations with higher PV production and higher cooling load, and the annual PV electricity that supplies the loads varies from 24 to 36% according to the seasonal variations of PV-load correlation. The levels of exported electricity into the grid are high in Brazil with annual mean power peaks surrounding 0.7 but can surpass 0.8 in the sunniest periods. The economy demonstrates the building achieves grid parity from 6 to 18% discount rates and the payback time is given for different scenarios of investment costs, discount rates and electricity tariffs. [ABSTRACT FROM AUTHOR]

Abstract: Vehicle-to-grid (V2G) energy transfer in a smart grid environment opens a new revenue opportunity for electric-drive vehicles (EVs), and might reduce grid operation costs in demand-constrained urban feeders where peak-electricity prices are high. This paper analyses the peak demand energy market for V2G in the urban region of Florianópolis, Brazil. The article describes known V2G-concepts and introduces two different dispatch strategies developed for the Brazilian energy market in the light of new tariff regulations, which are expected to go into effect starting in 2014. It turns out that electric-drive vehicles may be used as a grid-stabilisation strategy, but the announced tariff regulations may lead to a destabilisation if there are too many cars offering their internal storage for V2G grid support. Adequate energy policy strategies must be introduced to avoid the conflicting interests that might stem from the different perspectives of grid operators and EV owners. In contrast to previous analyses, this research assumes the battery degradation as a function of depth of discharge (DOD), which is known for a specific battery. [Copyright &y& Elsevier]

With the declining costs of photovoltaics (PV), a recent and widespread uptake of residential rooftop PV is underway in Brazil and many other sunbelt countries. Electricity consumers produce some or all their energy and become prosumers = producers + consumers. We present a method to evaluate the role and benefits of residential rooftop PV to prosumers and show a case-study using one of the 1250 PV-powered households in the "Celesc PV Bonus Project", promoted by the local distribution utility Celesc to demonstrate our method in Florianópolis-Brazil. The methodology was divided into five principal stages: (i) Solar resource at the site; (ii) PV system performance indicators; (iii) Consumption profiles; (iv) CO 2 emissions avoided and; (v) Comparative analysis between the individual PV rooftop case study with the average of PV households in the Florianópolis region. From the utility's perspective, the annual electricity consumption was reduced by 18% after PV integration. From the prosumer's perspective, the total annual consumption increased by 8%. However, the annual reduction in electrical utility expenses was 54%. The adoption of rooftop PV in residential households in Brazil was demonstrated to be advantageous, and payback times are still on a downward trend due to the continuing price reductions experienced by the PV technology. • Legislation and declining costs led to a widespread adoption of rooftop PV in Brazil • 1250 identical rooftop PV systems were installed by local distribution utility • Annual electricity bill was reduced by over 50% • As conventional energy prices are increasing, payback times will further decline • Instantaneous self-consumption of PV generation was below 20% [ABSTRACT FROM AUTHOR]

Highlights: [•] New bis-perylene dyads synthesized. [•] Photophysical and spectroscopic properties determined. [•] Energy matches for triplet–triplet energy transfer with C60 ideal. [•] Non-coherent photon upconversion observed and characterized. [Copyright &y& Elsevier]

Brazil faces challenges of both food insecurity and energy poverty, particularly affecting its rural and marginalized populations, despite being a global agricultural powerhouse. Simultaneously, Brazil has exceptional solar radiation resources and the solar photovoltaic (PV) technology has been rapidly growing. Agrivoltaic technology (AV) can represent a promising PV application for more efficient land-use, combining energy generation with agricultural activities. While Agrivoltaic Systems (AVS) have gained traction globally, Brazil is still in the early stages of implementation, with only a few pilot projects so far. To assess the potential of AVS in the Brazilian context, a comprehensive study of the global state-of-the-art in AV was carried out, along with an assessment of the existing regulatory energy framework in Brazil and the diverse agricultural characteristics of the country. Among the results, the existing distributed generation regulations and financing opportunities offer potential, particularly for small-scale farmers, and the adaptability of the AVS can generate technical and social benefits across the diverse Brazilian agricultural regions. However, addressing challenges such as adapting the technology to local agricultural practices and conditions, the lack of specific AV regulations or guidelines, and the lack of specialized professionals is crucial. Drawing from international experiences, Brazil can leverage AVS to promote clean energy access and empower rural communities, bridging its agricultural and energy potential with critical social needs. • Agrivoltaics demonstrate adaptability across diverse Brazilian agricultural regions. • Small-scale farmers can benefit from agrivoltaics within existing regulations. • Main challenges are the high CAPEX, professional training and absence of guidelines. • There are existing funding possibilities adequate for agrivoltaics in Brazil. • Agrivoltaics can enhance food and energy security in the country. [ABSTRACT FROM AUTHOR]

Abstract: The typical electrical distribution system shows a passive characteristic in relation to power flows (i.e. unidirectional power flows from substation to loads along the feeder). However, with the inclusion of solar photovoltaic (PV) generators along the feeder, this behavior is changed, and characteristics related to power quality, such as voltage level and total harmonic distortion (THD), may be affected. This paper presents the analysis of power quality in a feeder of the urban grid in the city of the Florianopolis, Brazil, with the integration of grid-connected PV systems as distributed generation. The analysis of power quality is based on real measurements of THD on an existing 12kWp PV pilot plant installed in the urban environment, and power flow simulations of a hypothetical PV system of 4.2MWp distributed in the same area, using the ANAREDE software. The power flow simulations allowed assessing the voltage level, the direction of power flow and loading of the distribution lines. The introduction of limited amounts of PV generation as distributed generation in the urban environment was found to be beneficial in several aspects: better voltage profile; power loss reduction and improvement in total harmonic distortion of the voltage (THDv). Furthermore, photovoltaics as a distributed generation source can also postpone feeder capacity upgrading investments. [Copyright &y& Elsevier]

An analytical approach to evaluate and to optimize the life cycle savings of hybrid diesel-photovoltaic plants is carried out. The life cycle savings is evaluated, considering one or more diesel generator sets, operating in different fixed power levels, with special attention to the case of high specific fuel cost. The condition under which optimum photovoltaic module area exists is analyzed. In the particular region of the northern part of Brazil, it is shown that there are several favorable conditions to implement photovoltaic generation, in the range of current electricity tariffs and diesel oil costs practiced in the market. [Copyright &y& Elsevier]

• Analysis involving BIPV integration, orientation, shadings and performance were conducted. • High-time resolution energy and irradiance data were collected from PV systems at the same site. • PV systems oriented from 0° to 270° and tilted from 0° to 20° had less than 4% in losses of irradiation. • BIPV systems can perform well even when not ideally tilted and/or oriented, and/or shaded. • PV modules can be more freely used as building materials in architectural integration. In a positive-energy building (PEB), the energy generation is higher than the required for the building's operation, including charging electric vehicles. That is the case of the Fotovoltaica-UFSC Laboratory, a solar energy research building, located in Florianópolis – Brazil (27°S; 48°W), and its electric bus (eBus), supplied by on-site building-integrated (BIPV) and ground-mounted (GM) photovoltaic (PV) systems. In order to assess the performance of BIPV systems from architectural perspectives, three not ideally positioned BIPV systems that use different technologies (c-Si, CdTe and CIGS), tilt angles, and azimuthal deviations were compared with two ideally oriented and tilted GM systems (CdTe), operating at the same warm and sunny site with simultaneous irradiance and energy data collected at high time resolution. All PV systems are installed in an urban environment, with complex aspects of architectural integration, orientation, partial shadings and performance. These aspects were analyzed in detail in this study. In addition, comparisons between real data measurements of all PV systems and PVSyst® software simulations were carried out. Results have shown that BIPV systems presented, in average, higher yields and performance ratios (PRs) than GM systems, and the real measurements validated the expected energy, even for PV systems with complex environment and tilt angle variations connected to the same inverter. In conclusion, PV modules can be more freely used as building skin and/or materials in architectural integration, as BIPV systems can perform well even when not ideally positioned and partially shaded, since the electrical system design supports architectural decisions. [ABSTRACT FROM AUTHOR]

• Area-intensive PV power plant topology scenarios were optimized. • Simulation of over 26,700 combinations using a PV system sizing software tool (PVsyst) were carried out. • Area-related utility-scale solar power plant optimization method was developed. • Best topology leads to 12.4% reduction in LCOE, and 91% higher area-related energy yield. This paper deals with the optimization of utility-scale, single-axis tracking PV power plant design, and suggests the use of a new evaluation metric Y AREA , represented by the annual energy yield normalized by the PV power plant area. This metric takes into account both the energy yield (MWh/MWp) and the total energy production efficiency of the PV plant (MWh/m2), performing an optimization of both yield and available area. To illustrate and validate the proposed method, historical solar irradiation data were treated and used as input data for the creation of a large number of PV power plant topology scenarios spread over the Brazilian 8.5 million km2 national territory, and a case study was presented to illustrate the proposed method. The new metric showed important results for the PV plant design decision-making process, indicating a technical optimization complemented by the evaluation of the LCOE, leading to an economic optimization. While the topology defined through Y AREA presents an average of 12.4% reduction of the maximum LCOE found, it presents a 58.9% enhanced Y AREA and 91.4% more energy generated per surface area, almost doubling the investment potential over an area. [ABSTRACT FROM AUTHOR]

• Solar and wind resources have a relevant temporal complementarity in the Brazilian NE. • Energy mix 40% wind and 60% solar requires minimal storage capacity to supply Brazilian NE load. • Role of storage in reducing the transmission infrastructure needs for renewable energy is evaluated. • Storage increases dispatchability of utility-scale wind and solar power plants. • _______________________________________________________________________________________________ Solar and wind sources together provided more than half of the Brazilian Northeast electricity generation in 2019. This growing share of renewable energies in the Brazilian energy matrix increases the importance of portfolio optimization and the energy storage management. This paper assesses the complementary nature between wind and photovoltaic generation in the Brazilian Northeast, and how this complementarity, together with energy storage, can reduce the shortcomings that the corresponding natural resource intermittency imposes on these sources. The work consists of two main analyses: (i) analysis of the capability in supplying the Brazillian Northeast region power demand with a hybrid wind + solar + storage power plant; and (ii) contingency optimization analysis for hybrid wind + solar + storage power plants. The results show that wind and solar resources are consistently complementary in the region, with a daily Pearson's Correlation Coefficient of −0.51. Also, the load supply analysis shows that a renewable energy mix based on a 40% wind and 60% solar share would require the equivalent of only 6% of its annual generation in storage capacity. An energy curtailment analysis showed that the complementary nature of the wind and solar resources, together with energy storage, can lead to a reduction of up to 11% in transmission capacity demand. [ABSTRACT FROM AUTHOR]

Utility-scale photovoltaic (PV) generation is being ramped-up in Brazil in recent years, as a result of intense price reductions. Extreme operating temperatures, high humidity levels, and a blue-biased distribution of irradiance in comparison with the standard ASTM G-173 spectrum, lead to contrasting operational outputs of the various commercially-available PV technologies. The performance assessment of six different PV technologies installed at eight different climatic regions in Brazil is presented. This R&D project evaluates eight identical, 54 kWp Evaluation Sites (ESs), all with the following PV technologies: amorphous-silicon (a-Si), microcrystalline-silicon (μc-Si), cadmium-telluride (CdTe), copper-indium-gallium-diselenide (CIGS), mono- and multi-crystalline silicon (c-Si and m-Si). All installations operate at a fixed-tilt equal to the corresponding local latitude. Electrical and environmental parameters at all sites are measured continuously at 1-s intervals. Results show a detailed energy loss analysis for all technologies. Thin-film PV modules with a low temperature-coefficient of power presented superior performance. Crystalline silicon modules revealed intense degradation in areas with high relative humidity and temperature. Cloud-edge and cloud-enhancement effects of solar irradiance resulted in irradiance peaks of 1823 W/m2, with long overirradiance events which lasted many minutes over 1600 W/m2, resulting in frequent blowing of string fuses when manufacturers maximum fuse ratings were observed. • c-Si modules revealed intense degradation in areas with high humidity and temperature. • Thin-film technologies presented a superior performance for most regions in Brazil. • Overirradiance led to blowing of string fuses when maximum fuse ratings were observed. • Optimum time resolution for irradiance data averaging is 1 min. [ABSTRACT FROM AUTHOR]

• The highest overirradiance event in Brazil at an altitude of 32 m sea level is 1845 W/m2. • Overirradiance led to blowing of string fuses when maximum fuse ratings were observed. • Optimum time resolution for irradiance data averaging is one minute. In contrast to the decades-long accumulated experience of photovoltaic (PV) installations in more temperate climates, the effects of some extreme operating temperatures and extreme solar irradiance levels start to become more noticeable with the uptake of large-scale PV in the sunbelt regions of the world. One such effect is caused by extreme solar overirradiance events, which up to now have been reported in the literature much more for their scientific interest than as a potential problem affecting the operational performance of PV power plants. Solar overirradiance events with a time span of tens of seconds or minutes are associated with the high operating temperatures prevailing in the field at many sites where utility-scale PV power plants start to become widespread, deleterious effects can be observed, which will negatively impact the performance of these generators. Using irradiance data from seven solar measuring stations deployed over distinct regions in Brazil, many of which are hosting megawatt-scale PV power plants, this paper reports on several extreme solar overirradiance events, with measured values above 1367 W/m2 up to 1845 W/m2, lasting from many seconds to a few minutes. Analysis of impacts and consequences from these events on the operational performance of PV generators are addressed, mainly focused on combiner box fuses, inverter overload losses, and inverter maximum power point tracker. [ABSTRACT FROM AUTHOR]

With the substantial growth of solar photovoltaic installations worldwide, forecasting irradiance becomes a critical step in providing a reliable integration of solar electricity into electric power grids. In Singapore, the number of PV installation has increased with a growth rate of 70% over the past 6 years. Within the next decade, solar power could represent up to 20% of the instant power generation. Challenges for PV grid integration in Singapore arise from the high variability in cloud movements and irradiance patterns due to the tropical climate. For a thorough analysis and modeling of the impact of an increasing share of variable PV power on the electric power system, it is indispensable (i) to have an accurate conversion model from irradiance to solar power generation, and (ii) to carry out irradiance forecasting on various time scales. In this work, we demonstrate how common assumptions and simplifications in PV power conversion methods negatively affect the output estimates of PV systems power in a tropical and densely-built environment such as in Singapore. In the second part, we propose and test a novel hybrid model for short-term irradiance forecasting for short-term intervals. The hybrid model outperforms the persistence forecast and other common statistical methods. [ABSTRACT FROM AUTHOR]

Challenges such as partial shading and non-optimal tilt and azimuthal deviations are common in building-integrated photovoltaic systems (BIPV). Therefore, it is important to be aware of the consequences on systems performance metrics, namely annual specific yield and performance ratio for these specialised applications. This paper describes detailed analyses of shading effects, irradiation resource availability and module temperature on the performance metrics of individual subsystems of a rooftop BIPV installation in a high-rise building embedded in a high-density environment in Singapore. The study indicates that a shading analysis during the design phase can highly improve PV systems performance by giving careful consideration about shaded modules to optimise the PV module string design. [ABSTRACT FROM AUTHOR]

Anthropogenic haze, caused at least in parts by forest and agricultural land clearing fires in Sumatra (Indonesia), is occasionally causing air quality issues in Singapore, located 150–300 km east of the majority of these “hot spots”. The resulting air pollution partially blocks sunlight from reaching the ground, and consequently affects the electric power generation of solar photovoltaic (PV) systems in Singapore. In this work, a methodology is presented to estimate the haze-induced reduction of the light intensity reaching PV panels and the corresponding loss in the electric energy yield. An assessment of a major haze event in June 2013 is the basis for the loss analysis, which takes into account data filtering techniques in order to isolate cloudless conditions for inter-comparison between clear and hazy days. Data from previous years in non-hazy conditions serve as baseline for the determination of the clear sky conditions for Singapore. The novel method is further applied to investigate the power output of ten PV systems in Singapore during the June 2013 haze event. It is found that poor air quality levels during this event caused yield losses of PV systems in Singapore in the range of 15–25%. [ABSTRACT FROM AUTHOR]

Highlights: [•] Airport building envelopes can receive 90–95% of the maximum available annual solar irradiation. [•] The choice of PV technology has a large impact on the annual energy generation potential. [•] Compared with BIPV, BAPV leads to lower installed peak power capacity and annual energy density. [•] Compared with BIPV, BAPV leads to higher annual energy yields. [•] Differences in performance ratio (PR) between BIPV and BAPV are negligible. [Copyright &y& Elsevier]

Abstract: Brazil faces a continuous increase of energy demand and a decrease of available resources to expand the generation system. Residential buildings are responsible for 23% of the national electricity demand. Thus, it is necessary to search for new energy sources to both diversify and complement the energy mix. Building-integrated photovoltaic (BIPV) is building momentum worldwide and can be an interesting alternative for Brazil due its solar radiation characteristics. This work analyses the potential of seven BIPV technologies implemented in a residential prototype simulated in three different cities in Brazil (Natal, Brasília and Florianópolis). Simulations were performed using the software tool EnergyPlus to integrate PV power supply with building energy demand (domestic equipment and HVAC systems). The building model is a typical low-cost residential building for middle-class families, as massively constructed all over the country. Architectural input and heat gain schedules are defined from statistical data (Instituto Brasileiro de Geografia e Estatística—Brazilian Institute for Geography and Statistics (IBGE) and Sistema de Informações de Posses de Eletrodomésticos e Hábitos de Consumo—Consumer Habits and Appliance Ownership Information System (SIMPHA)). BIPV is considered in all opaque surfaces of the envelope. Results present an interesting potential for decentralized PV power supply even for vertical surfaces at low-latitude sites. In each façade, BIPV power supply can be directly linked to local climatic conditions. In general, for 30% of the year photovoltaic systems generate more energy than building demand, i.e., during this period it could be supplying the energy excess to the public electricity grid. Contrary to the common belief that vertical integration of PV is only suitable for high latitude countries, we show that there is a considerable amount of energy to be harvested from vertical façades at the sites investigated. [Copyright &y& Elsevier]