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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]

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]

ABSTRACT This paper aims at investigating if the balance between aesthetics and performance in building-integrated photovoltaic (BIPV) systems is possible to be achieved in the tropics. To accomplish this objective, three BIPV systems located in Singapore with photovoltaic (PV) systems playing an aesthetically appealing role in their architecture were analysed in detail for a 1-year period. The systems were analysed regarding the available solar irradiation, the shading profiles and the resulting yield and performance ratio (PR) in order to compare the performance of different subsystems with variable architectural characteristics and string configurations. All systems are partially shaded in the early morning or late afternoon, a common situation inherent to BIPV systems. Results show that even with a theoretical non-optimal combination of azimuthal deviations and tilt angles, some PV systems show better performances in terms of yield and PR than those which are installed at more ideal conditions. The high ratio of diffuse irradiation in Singapore, the distance of shading obstacles and times when shading occurs and the subsystem and string configurations strongly influence the systems performance results. With the declining costs of PV systems, BIPV can offer attractive solutions with high integration appeal, architectural sophistication and the promotion of sustainable energy supply. In the tropics, rooftop BIPV systems can perform with relatively small losses and be aesthetically appealing when compared with optimally tilted and oriented PV generators. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

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: The integration of photovoltaic (PV) modules on building façades and rooftops is an ideal application of solar electricity generators in the urban environment. Maximum annual performance of grid-connected PV is usually obtained with modules tilted at an angle equal to the site latitude, facing the equator. The performance of PV systems not tilted and oriented ideally can drop considerably, depending on site latitude. With grid parity – when the cost of solar electricity becomes competitive with conventional electricity – expected in many countries in the present decade, a more widespread application of PV on buildings is expected, and in this context the main goal of this paper is to demonstrate that good compromises between form and function are possible. In this work we compare the annual energy generation of a curved BIPV system installed as a car port rooftop, with an ideally-oriented and tilted, flat BIPV system installed as a building’s rooftop cover at a low-latitude site (27°S). For the one-year period analysed, the curved-shape BIPV system annual yield was 12% lower than that of the reference BIPV system, and during the summer months (November to February), the curved BIPV installation presented a higher energy yield than the latitude-tilted generator. With these results we show that a good compromise can be reached between form and function in BIPV systems. [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]

• 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]

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]

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]

• 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]

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]

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]