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Purpose: Energy consumption and renewable energy sources are included in the goals for the 2030 Sustainable Development Goal 7 (SDG7) agenda, and target buildings are the biggest electricity consumers. In turn, Netzero energy buildings (NZEB) contribute to achieve SDG7 goals. This paper aims to identify which Brazilian higher education institutions (HEIs) practices contribute to developing the NZEB concept. Design/methodology/approach: Case studies were selected to identify which implanted practices applied by HEIs in Brazil, listed in the UI GreenMetric 2020 Ranking, are related to the NZEB concept. The implemented sustainable practices were also analyzed to evaluate the connections and impact between universities and the local community. Findings: Results show the lighting and air conditioning retrofit were among the most common practices related to energy efficiency to reduce consumption. For renewable energy generation, photovoltaic solar energy is the most common practice used by HEIs. Research limitations/implications: Only Brazilian HEIs listed in the UI Green Metric Ranking were analyzed. No standard regulation or formal reports support the wide dissemination of the strategies adopted by HEIs in Brazil. Practical implications: The strategies adopted by HEIs related to Netzero buildings can reduce emissions, optimize operating costs and improve building comfort conditions, which connect all SDGs. Social implications: HEIs can promote awareness related to energy use and clean energy generation within the local community. Originality/value: This paper presents the most common strategies adopted by Brazilian HEIs. However, limitations related to lack of strategies, data transparency and specific Netzero energy regulation were also found. These issues can hinder other HEIs to adopt similar strategies and contribute to the promotion of SDG7 in Brazil. [ABSTRACT FROM AUTHOR]

The world is moving towards a low-carbon economy through renewable energy sources. In this context, concentrating solar power (CSP) technologies can exploit the rich solar resource in Brazil, diversifying the national electricity mix. The aim of this paper is to support the insertion of CSP generation in the Brazilian bottom-up model MATRIZ by analyzing the environmental performance of three CSP technologies: (i) solar tower power (STP) with a thermal storage system (TSS) of 7.5 h; (ii) solar thermal parabolic trough (STPT) with a TSS of 6 h; and (iii) STPT without TSS. From a life cycle perspective, their freshwater consumption and greenhouse gas (GHG) emissions are addressed by employing the software SimaPro, the Ecoinvent database, and the ReCiPe 2016 method, as well as information from the system advisory model (SAM) and the literature. As a result, STP is the most environmentally sound CSP alternative, presenting lower GHG emissions and water consumption than the two STPT technologies. In general, CSP generation proves to be more environmentally attractive than some fossil-fired power plants and renewable energy sources. Moreover, moving the manufacturing of CSP technologies to Brazil has the potential to reduce GHG emissions from the upstream processes of their value chain. [ABSTRACT FROM AUTHOR]

This paper aims to analyze the information about protection of technologies related to distributed generation (DG) of electric energy, available in the Brazilian patent bank, in the period between 2011 and 2020. Considering that the energy sector has strategic role for companies and countries, analyzing technological trends in the area can help management and decision making. As a methodological procedure, (1) data were collected from the national database of the Instituto Nacional de Propriedade Industrial - INPI (National Institute of Industrial Property) -- in July 2020, (2) associated with keywords and the Classificação Internacional de Patentes - IPC (International Patent Classification) for research and (3) treated with the aid of Microsoft Excel and IBM SPSS Statistics version 25 software. The variables found and analyzed were: nature of the patent; order status; international classification; year of filing; publication of request; countries of origin of depositors; main depositors; state of origin of depositors; electrical system structure; and types of energy sources. The results demonstrated that the number of patent filings fluctuated over the years; that there was a significant growth in the number of deposits in the years that normative resolution n° 482/2012, responsible for regularizing DG in Brazil, was published or revised and that most of the technologies deposited are intended for power generation, with emphasis on that use wind energy. [ABSTRACT FROM AUTHOR]

After harvest, usually a significant amount of crop residues are available and part of it can be a feedstock for biomass energy. This paper's objective is to quantify sustainable residual biomass from corn harvesting, husk leaf, and cob, and its solid-fuel characterization for energy co-generation assessment. The methodology considers geographical distributions of corn production on a municipal basis, at Mato Grosso do Sul (MS) State in Brazil. Residual biomass from corn harvest has its mass fractions and energy characteristics determined via proximate and ultimate analyzes, bulk density, and heating values. Also, assessment of energy and power obtained by using co-generation power plants technology. The conclusions identify that residual biomass from corn harvest (husk leaf and cob) have large amounts available for energy use (~190.106 kg), and a main one geographic micro-region at MS. Its characteristics as solid fuel, i.e., HHV~18 MJ.kg-1 and TMC,db <10%, as well as high availability for oxygen for combustion (TO ~43%) and low ash content (TAsh < 4%) corroborate with its energy use, as in co-firing with sugarcane bagasse or coal thermal power plants. Bulk density values suggest densification as an interesting option for the commercialization of pellets or briquettes. Assessment of energy and power has a significant contribution to the Dourados micro-region (~2 GWElectric) and could attend farm and other rural energy demands through co-generation power plants. Altogether, husk leaf and cob are adding-values co-products that can play a significant role in the corn productive chain. [ABSTRACT FROM AUTHOR]

This paper performs Fourier cointegration and causality tests to analyze the effect of renewable energy generation, globalization, and agricultural activities on ecological footprint and carbon dioxide (CO 2) emissions in BRIC countries for the period 1971–2016. The Fourier ADL cointegration test supports a long-run relationship between the considered variables in Brazil and China. The long-term elasticities indicate that globalization increases the pollution indicators, while renewable energy generation significantly reduces environmental pressure in China. Moreover, globalization increases CO 2 emissions, while renewable energy generation improves environmental quality in Brazil. The causality results show the existence of bidirectional causality between agriculture and environmental degradation; unidirectional relationships from globalization to the ecological footprint and CO 2 emissions; and renewable energy generation to the ecological indicators. Overall, these findings reveal the importance of renewable energy in combating environmental degradation. Based on the above results, renewable energy generation can significantly reduce environmental pollution in Brazil and China. However, renewable energy does not affect environmental pressure in Russia and India. Therefore, these countries should differentiate the current renewable energy generation policies to achieve their sustainable development goals. [ABSTRACT FROM AUTHOR]

The vulnerability of electric potential generation from water resources has been evidenced due to uncertainties of climatic origin and energy planning. Changes in rainfall regimes are multifactorial phenomena difficult to model. Rainfall is the main natural way of restoring the reservoir levels of hydroelectric power plants. The reduction in rainfall levels may increase in the coming years, resulting in a probable change of the energy matrix configuration of the state of Minas Gerais (MG). This could reduce the share of renewable sources increasing dependence on the importance of energy from fossil fuels, which are the immediate primary sources of energy available. Prior examinations have portrayed the depletion of hydroelectricity in Brazil, or its macro-regions, however this work tries to supply a more focused look at the effects on the electricity and social sectors of the state of Minas Gerais. The study developed in this paper aims to investigate the hydrological potential alteration impacts and consequences on the energy matrix of the state, the greenhouse gas emissions and the social reflexes of these changes due to scenarios motivated by climate change. The investigation intends to show the importance of the water-energy-emissions nexus for energy planning and decision-making, in order to evaluate the best options for dealing with adverse and potentially destabilizing conditions. The results of the analyses show that while hydropower demand was 5.24 Mtoe in 2015, in 2030 the supply of hydropower will be 5.81 Mtoe and 4.72 Mtoe, for the conservative and severe scenarios, respectively. In addition, the effect of climate change may require an increase in the share of non-renewable sources in the energy matrix, which could increase CO 2 e emissions from 4.2% to 7.4% by 2030, compared to the levels in 2016. • Reduction in rainfall levels will change the energy matrix configuration of MG state. • Population growth will boost demand for energy. • It is shown the importance of the water-energy-emissions nexus for energy planning and decision-making. • The energy matrix may considerably increase the CO 2 e emissions by 2030, compared with 2016 levels in the MG state. [ABSTRACT FROM AUTHOR]

Summary: Alternative sources of electricity have been growing recently despite their intermittence, which makes it impossible for these sources to guarantee constant and uninterrupted supply of electricity. Energy storage systems, such as pumped‐storage (PS) power plants, can help to mitigate the intermittence of these sources. In Brazil, intense growth of intermittent sources has led the generation sector to high exposure to the spot market. Thus, Brazilian electricity sector has recently turned its attention to energy storage methods as a way of diminishing such exposure. However, Brazilian electricity‐sector regulatory framework is not prepared for energy storage systems remuneration. This paper proposes a regulatory framework to insert hybrid electric generation units composed of PS and intermittent sources in Brazilian energy market. A linear optimization model exemplifies the operation of such system by minimizing costs for 1 day. The model was tested in three different scenarios, allowing comparison of operational costs and other aspects of the operation. The results demonstrate how a PS can help covering peak demand by storing energy to be used at moments when generation from intermittent sources is not sufficient. In the proposed regulatory framework for hybrid plants, expenses with spot market purchases can be diminished either by completely avoiding it or by purchasing only during lower demand level periods. [ABSTRACT FROM AUTHOR]

Abstract The Brazilian electricity system is an important example of a large country relying on a high renewable energy matrix with a major focus on hydropower, which has historically allowed for low carbon electricity production. However, the increase in the demand and climate change impacts on the availability of these renewable resources represent important challenges for long-term power planning. The contribution of this paper is twofold: Firstly, a first attempt to use the EnergyPLAN model for the analysis of the Brazilian electricity sector and in particular to study future scenarios is presented. Secondly, the possibility of achieving a 100% RES system is also addressed. The 100% RES scenario is found to be theoretically possible but a substantial increase in the overall installed capacity would be required, to support the grid mainly during the spring and summer season. The results underline the importance of seasonal complementarity of hydro and wind power and reveal how an increase in RES would add exportation potential, reducing also the Brazilian external energy dependency. The study identifies risk factors for these high RES scenarios and outlines several avenues for future research to address cost, environmental and technical uncertainties of the system. Highlights • The Brazilian power sector is analysed with EnergyPLAN computer model. • Renewable scenarios are compared for technical, cost, emissions and risk parameters. • The importance of seasonal complementarity of hydro and wind power is outlined. • The 100% RES scenario results in full decarbonization of the system at higher cost. • The 100% RES scenario results in higher exportation and lower importation potential. [ABSTRACT FROM AUTHOR]

The ethanol production chain is a complex system with a considerable number of actors and relationships. While Brazil stands out as a major producer of sugarcane ethanol, the production model in the north-eastern and southern regions is typically formed by small and medium production units, mostly associated to family-farming and associative production. This feature changes the relationships and profiles of the production chain, requiring understanding for the development of appropriate environmental, political, economic, social, ethical, and technological actions. This paper systemically maps variables that act in ethanol production chain in Southern Brazil, seeking to understand the interrelationships among its actors. Data collection was based on a review of the technical and academic literature and semi-structured interviews with different experts and actors of the chain. Systems dynamics diagrams model how the chain is configured and the main cause-effect interrelationships between the actors identified. Scenario analysis supports the analysis and discussion of the modelled context, seeking to contribute to the discussion about the competitiveness and economic sustainability of biofuel chains integrating associative production and family-farming. [ABSTRACT FROM AUTHOR]

The technology of photovoltaic power generation has been increasingly regarded in many countries as an alternative to reduce the environmental impacts associated with climate changes and dependence on fossil fuels. Countries such as Germany and other European countries have been developed specific regulatory mechanisms to encourage its use either by government programs or by financial and/or tax incentives. In Brazil, despite the large existing solar potential, the encouragement to technology is still incipient. This paper aims to demonstrate the key aspects of the evolution of regulatory incentives to use photovoltaic solar energy in Brazil and present the technologies and characteristics of photovoltaic power generation. [ABSTRACT FROM AUTHOR]

Stabilization at concentrations consistent with keeping global warming below 2 °C above the pre-industrial level will require drastic cuts in Greenhouse Gas (GHG) emissions during the first half of the century; net negative emissions approaching 2100 are required in the vast majority of current emission scenarios. For negative emissions, the focus has been on bioenergy with carbon capture and storage (BECCS), where carbon-neutral bioenergy would be combined with additional carbon capture thus yielding emissions lower than zero. Different BECCS technologies are considered around the world and one option that deserves special attention applies CCS to ethanol production. It is currently possible to eliminate 27.7 million tonnes (Mt) of CO 2 emissions per year through capture and storage of CO 2 released during fermentation, which is part of sugar cane-based ethanol production in Brazil. Thus, BECCS could reduce the country’s emissions from energy production by roughly 5%. Such emissions are additional to those due to the substitution of biomass-based electricity for fossil-fueled power plants. This paper assesses the potential and cost effectiveness of negative emissions in the joint production system of ethanol and electricity based on sugar cane, bagasse, and other residues in Brazil. An important benefit is that CO 2 can be captured twice along the proposed BECCS supply chain (once during fermentation and once during electricity generation). This study only considers BECCS from fermentation because capturing such CO 2 is straightforward, thus potentially representing a cost-effective mitigation option for Brazil compared to other alternatives. The assessment shows that fuel prices would increase by less than 3.5% due to the adoption of BECCS from fermentation, while increasing investors’ revenues are sufficient to compensate for the investment required. With appropriate government subsidies, or by sharing BECCS costs between all car fuels and all electricity supplied by hydro and bioelectricity, the increment in ethanol and electricity prices could be less than 1% for the final consumer. Meanwhile it would supply 77.3% of all cars’ fuel (private cars) and 17.9% of all electricity in Brazil. [ABSTRACT FROM AUTHOR]

This paper presents a comparative analysis of energy governance regarding nonconventional renewable energy sources (NCRES) in Brazil and Germany. Brazil is a world leader in the use of conventional renewable energy sources, such as hydro power, while Germany has been achieving outstanding results in fostering NCRES. The focus is on two critical issues: the legal and regulatory framework and the institutions created to support the NCRES market development. The comparison shows that, despite the very different energy situations and policy drivers, valuables lessons can be extracted from the German experience. The main lesson for Brazil is to think NCRES as a strategic opportunity to rely less on fossil fuel and large hydroelectric power plants, to decentralize the electric power sector, to use the huge solar, biomass and wind power potential available in the country and to create a environment-friendly NCRES industry. To this end, three critical points were identified: (1) the legal and regulatory framework should be improved; (2) long-term energy planning taking into account social, economic and climate issues and; (3) the current institutions supporting NCRES in Brazil should be upgraded and/or new ones, such as more specific energy agencies, should be created. [ABSTRACT FROM AUTHOR]

Hydropower is the backbone of the Brazilian electricity generation sector. Even though the use of this resource is advantaged in terms of greenhouse gas emissions, last years׳ severe droughts have exposed the country׳s huge dependency on hydroelectricity. Brazil׳s electricity supply system has shown to be vulnerable to electricity shortages and has demanded significant overhaul in order to address its challenges. The present paper provides a comprehensive review of the current status of the Brazilian electricity sector and discusses diversification of electricity generation mix as a strategy to improve electricity supply security in the country. An overview of the main features of the energy sources applied in Brazil is also presented through a review of the latest available generation data. The central section of this work is a discussion of the main causes of the current crisis and the future role of renewable energy sources in a 10-year perspective. [ABSTRACT FROM AUTHOR]

The potential for sugarcane ethanol from Brazil to mitigate GHG emissions is undeniable, but the way that ethanol is produced during the agricultural and industrial phases will ultimately determine its benefits to society. In this paper, we evaluate the environmental impacts of sugarcane agriculture and ethanol production in Brazil as management practices continue to change and production expands to new frontiers. We focused our evaluation on the impacts on water, atmosphere, and soils, including how the application of organic and inorganic fertilizers and the accumulation of crop residue in the field affect emissions of greenhouse gases (GHG). We also addressed the impacts of land use changes on threatened biomes and discussed some of the present obstacles regarding conservation and restoration efforts. We concluded that, since a similar assessment was put forth in 2008, our knowledge about the environmental impacts of sugarcane ethanol in Brazil has advanced with regard to soil degradation, nitrogen dynamics, and soil carbon stocks. However, more information is still needed about the impacts of the increasing use of pesticides, herbicides, and fertilizers in sugarcane agriculture, especially on water resources. Furthermore, without a better understanding about how landscape fragmentation affects the biodiversity of terrestrial and aquatic tropical ecosystems and the services they provide, policies created to protect and restore them may be ineffective. On the other hand, the use of presently available scientific information to end unsustainable farming and the implementation of conservation strategies proposed by the Brazilian Forest Code could be a first step to guarantee that ethanol is produced more sustainably in Brazil. [ABSTRACT FROM AUTHOR]

The key objective of this paper is to analyze the techno-economic feasibility of this alternative for the Brazilian municipalities, classified according to population subgroups, using this parameter as a basis for the calculation of the municipal solid waste generated, the project costs and revenues. Different expenses were taken into consideration, like equipments and installation costs, operation and maintenance costs and the interest rate of the investment. In relation to revenues, they come from of the sale of electricity, the incomes of the recyclable materials, the fees paid by the Brazilian municipalities for the disposal of municipal solid waste in sanitary landfills and incomes by the carbon credits. An analysis of each population subgroup, combining three different economical scenarios was done, with an annual rate of interests of 10.58% for Scenario 1, 7.5% for Scenario 2 and 15% for Scenario 3. The economic feasibility was evaluated using as economic indicators the net present value and the internal rate of return. The net present value was positive for the municipalities with more than 60,714 inhabitants for the Scenario 1, 34,203 for Scenario 2 and 259,845 for Scenario 3. A hypothetic gasification plant is capable to generate 905 kW/ton municipal solid waste for a population of 60,714 inhabitants (Scenario 1), 794 kW/ton municipal solid waste for a population of 34,203 inhabitants (Scenario 2) and 1065 kW/ton municipal solid waste for a population of 259,845 inhabitants (Scenario 3). It is concluded that the economic feasibility increases with the installation of bigger units, showing a positive scale up gains, therefore as higher the capacity of the installation lower the specific costs and higher are the benefits. [ABSTRACT FROM AUTHOR]

• Vector Shift Relay islanding detection capability versus system stability; • The need of Vector Shift Relay standardization for its secure applicability; • A Vector Shift Relay adjustment procedure for grid-tied synchronous generators; • A case study on Brazil's anti-islanding commissioning for distributed generation. The increasing electricity demand has encouraged consumers to invest in distributed energy resources and, among these, synchronous generators fed by biogas. One of the main concerns over this is the possibility of these sources feeding a section of the grid while a loss of mains, known as islanded operation. To prevent it, distributed generators must have protection devices that can identify this loss of connection. Vector Shift Relays are one of the most popular methods for island detection applied to synchronous generators. However, an increasing concern on false tripping of these relays has led the Brazilian electricity regulatory agency to ponder about their removal. In this paper, a detailed analysis of the Vector Shift Relay operation and configuration is done and a new procedure to determine the relay threshold value is proposed, considering different power-load mismatches. It is shown that this protection device is quick to detect islanding when there is a power unbalance greater than 30% but it may risk false tripping if adjusted to a lesser power mismatch. Finally, a discussion is presented to show that there are issues with correctly using this device and still complying with current standards, and further investigations are recommended. [ABSTRACT FROM AUTHOR]

The micro- and mini-distributed generation (MMDG) has significantly increased after the normative resolution No. 482/2012 in Brazil; the installed capacity surpassed 7 GW in 2021. In the international context, a similar event was observed, whose process generated a cross-subsidy for other consumers, in addition to other problems that affect the economic balance of concessionaires. To mitigate this issue, the National Electric Energy Agency (ANEEL) is in the process of revising current rules. Thus, this study estimates the weight of this decision, through a methodology adapted from international assessment models, based on information from the Brazilian regulatory system. In order to achieve it, this paper presents metrics to define the potential market MMDG, based on the consumption patterns of consumers. Then, through time series analysis, the MMDG demand curve is estimated under two scenarios up to 2030. Finally, the economic impact on tariff adjustments and revisions, and their effect on the electric power concessionaires are evaluated. In the distribution companies of the Enel Group alone, economic losses are estimated at USD 1.2 billion by 2030; 53% of this will be passed on to consumers' tariffs. Thus, based on international experiences, it can be concluded that the best model is the adequate grid remuneration. [ABSTRACT FROM AUTHOR]

Abstract: This paper aims to identify and quantify the main potential environmental impacts of the sugarcane bagasse electricity generation in Brazil. To do so, it was employed the Life Cycle Assessment (LCA) technique based on primary and secondary data from three previous studies encompassing electricity generation, transmission and distribution processes. It was identified that the main impact potentials of this type of electricity generation in Brazil that should be addressed by decision-makers are the photochemical ozone, the human toxicity via soil and the nutrient enrichment ones, which are caused mainly by the sugarcane straw burning prior harvesting and the chemical application. In addition, it was found that non-renewable resources, renewable resources and energy consumption are also important issues that should be addressed mostly in the process of electricity transmission. [Copyright &y& Elsevier]

Abstract: Successful development of renewable energy technologies like solar photovoltaic energy (SPV) critically relies on its understanding and acceptance by consumers and institutional customers. Even in contexts of favorable support at the general level like in Brazil, their implementation faces multiple challenges, including low awareness, misperceptions, insufficient communication, and eco-labels' mixed record as information enhancing tools. This paper discusses how market research has been instrumental in developing the first SPV venture in Brazil, by identifying public's beliefs and level of support for alternative energies, and by testing reactions to a solar energy eco-label scheme proposed as key communication tool. The study indicates that expectations for return on investment are affected by a sustainability penalty, as well as by price and adaptation barriers. It also reveals an assessment gap between the concept and design of eco-label, which led to a new eco-label design capable of better addressing unfavorable beliefs, integrating expectations, and improving overall acceptance. [Copyright &y& Elsevier]

Abstract: The growing demand for electrical power and the limited capital invested to provide this power is forcing countries like Brazil to search for new alternatives for electrical power generation. The purpose of this paper is to present a technical and economic study on a 15kW solar plant installed in an isolated community, highlighting the importance of the need for financial subsidy from the government. It evaluates the importance of parameters such as the annual interest rate, specific investment, the marginal cost of expanding the electrical power supply and the government subsidy on amortization time of capital invested. [Copyright &y& Elsevier]

Abstract: The Brazilian North and Northeast regions have possibilities on harnessing tidal power, where the greatest tidal amplitudes are to be found. In the 1970s, a barrage constructed in the Bacanga estuary, a civil construction project for reducing the distance between the city of São Luís do Maranhão and the port of Itaqui, was planned to be the first Brazilian tidal power plant. The favorable conditions associated with the considerable tidal heights, which can be as much as 6.5m, made this an ideal place for building a pilot plant. Although, a scheme had been proposed to harness tidal energy in a conventional way with the use of the reservoir, the tidal plant in its original form was not implemented due economic and technical restrictions originated from the turbo generators chosen at that time. This paper presents an alternative concept for tidal power plant when the reservoir presents limitations caused by urban occupation, silting up and deterioration of the original structures. These limitations have been verified following the construction of the Bacanga barrage which led to an alternative proposal for the future installation of a pilot tidal power plant. The power generation possible to be harnessed was simulated through a model for each hour from the water head data, outflow, levels, areas and volumes of the reservoir and estuary. The development of the conceptual project, with the utilization of low-head turbines, a floating platform for the turbines and, particularly, taking into consideration those restrictions to be found at the present time, it can be concluded that Bacanga tidal power plant of is technically viable. [Copyright &y& Elsevier]

Hybrid polygeneration systems offer a great opportunity to meet growing energy demands with cost efficiency and environmental benefits. The identification of the optimal solution (configuration and operational strategy) is strongly affected by the relationship between the system and its surroundings. Previous studies have analyzed the influence of boundary conditions on the synthesis of polygeneration systems for buildings. However, local regulations are often disregarded or oversimplified in those studies. Therefore, this paper aims to evaluate the influence of legal conditions on the integration of renewable energy technologies in polygeneration systems for buildings. A comprehensive synthesis model is developed, including different types of legal conditions, such as power exchange modalities, subsidies/surcharges on energy prices and investment costs, and total ban on fossil fuels. Then, the model is applied to the case study of a Brazilian hospital. The current Brazilian net metering scheme is implemented. Results show that natural gas cogeneration is an attractive solution to cover the hospital's energy demands with or without the possibility of selling/exporting electricity. Also, the Brazilian net metering scheme, by itself, is not enough to ensure renewable energy deployment. An in-depth discussion about the conditions that would promote renewable energy integration is reported and recommendations are made on how current policies can be improved, including the need to explicitly address renewable technologies, the application of minimum renewable fractions, and the role of renewable heat/cooling. While the case study considers the specific circumstances in Brazil, it provides insights that can be extended to other countries or applications. • Synthesis model of hybrid renewable polygeneration systems for buildings. • Influence of legal constraints on the integration of renewable energy technologies. • Power exchange modalities, subsidies/surcharges, and fossil fuel ban are considered. • Technical, economic, and environmental analysis of a Brazilian hospital case study. • The Brazilian net metering scheme did not promote renewable energy technologies. [ABSTRACT FROM AUTHOR]

The global electricity sector is responsible for a large share of greenhouse gas. Renewable energy (RE) is a feasible alternative to maintain sustainable growth and economic development, as it appears to be a means to reduce emissions and decarbonize economies. Renewable energy projects present some uncertainties and flexibilities that are ignored by traditional methods of evaluation, such as the net present value (NPV), which can lead to undervaluation. This paper aims to assess the switch-output option and defer option for RE projects according to their features in the Brazilian electricity market. The real options approach (ROA) for RE projects seeks to capture the value of uncertainties and flexibilities that all projects have from an investor's point of view. Then, when we adopted a more sophisticated approach that values flexibilities and uncertainties for RE projects, it was possible to conclude that there was a clear increase in value when compared to traditional investment analysis methods like the NPV. • The penetration of renewable energy in the Brazilian Electricity Market is growing. • The Real Options Approach represents an alternative to traditional methods of investments analysis. • Real options deals with the inherent characteristics of renewable energy projects. • Real Options show an increase in value when compared to traditional methods. [ABSTRACT FROM AUTHOR]

This paper focuses on the estimation of annual energy production (AEP) by simulating the flowfield on a complex terrain located in the northeast region of Brazil using different numerical approaches: CFD RANS with k-ε and k-ω turbulence models (WindSim), simple mass-conserving (WindMap), and refined mesoscale (SiteWind). The last two are run through OpenWind software. Wind observations from five meteorological masts are used to adjust the models. Optimal layouts for a hypothetical wind farm with 50 wind turbines are obtained over each of the four wind fields to predict the power generation. As non-negligible differences are found on the spatial distribution of the winds simulated by the different models, the layouts are also substantially different. The AEP is calculated to compare scenarios varying the layouts over the wind fields. The distinct micrositing generate differences of up to 13 % on AEP prediction, which could mean the impact of an improper siting on the wind farm profitability. It is not plausible to categorically claim the superiority of accuracy of one model over the others. Nonetheless, the observed data provide an indicative that the refined mesoscale model was able to better capture the wind acceleration in the western region of the studied site. • CFD, mass-conserving and refined mesoscale approaches are used for micrositing study. • AEP prediction for a high wind farm potential area but scarce published works. • Wind power exploitation can be harmed if the turbine positioning is not well suited. • An improper siting of wind turbines can impact up to 13 % on AEP prediction. • A given numerical tool can not be categorically claimed as the most accurate. [ABSTRACT FROM AUTHOR]

This paper proposes a novel dynamic pricing scheme for demand response with individualized tariffs by consumption profile, aiming to benefit both customers and utility. The proposed method is based on the genetic algorithm, and a novel operator called mutagenic agent is proposed to improve algorithm performance. The demand response model is set by using price elasticity theory, and simulations are conducted based on elasticity, demand, and photovoltaic generation data from Brazil. Results are evaluated considering the integration effects of renewable energy sources and compared with other two pricing strategies currently adopted by Brazilian utilities: flat tariff and time-of-use tariff. Simulation results show the proposed dynamic tariff brings benefits to both utilities and consumers. It reduces the peak load and average cost of electricity and increases utility profit and load factor without the undesirable rebound effect. [ABSTRACT FROM AUTHOR]

Torrefaction has been investigated to improve the desirable properties of biomass as solid biofuel, usually used in natura as firewood in several countries. This paper has the main objective to present a broad characterization of the biomass Prosopis juliflora (P. juliflora), investigating its potential as a solid biofuel after its torrefaction process. The methodology was based on different procedures. The experimental runs were carried out at 230, 270, and 310 °C for 30 min, using a bench-scale torrefaction apparatus, with an inert atmosphere. In order to investigate the effect of temperature in constant time, torrefaction parameters were calculated, such as mass yield, energy yield, calorific value, base-to-acid ratio (B/A), and the alkaline index (AI). The physicochemical properties of the torrefied samples were determined and thermogravimetric analysis was used to determine the kinetic parameters at four different heating rates of 5, 10, 20, and 30 °C/min. Pyrolysis kinetics was investigated using the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) isoconversional methods. Highly thermally stable biofuels were obtained due to the great degradation of hemicellulose and cellulose during torrefaction at higher temperatures. The highest heating value (HHV) of the samples varied between 18.3 and 23.1 MJ/kg, and the energy yield between 81.1 and 96.2%. The results indicate that P. juliflora torrefied becomes a more attractive and competitive solid biofuel alternative in the generation of heat and energy in northeast Brazil. [ABSTRACT FROM AUTHOR]

There is consensus that the use of renewable energy must be expanded. More and more restrictions on the use of fossil derived fuels may open the way for an increased consumption of biomass event those so far not perceived as feasible, such some biomass residue. Energy derived from biomass residues may provide even more benefits because it may replace other sources of higher-grade energy while providing proper destination for residues. Biomass from pruning residue has been overlooked as an energy resource due to many limitations. This paper addresses the issue and the means for energy valuation of pruning residues while provides final destination for them. It presents a framework to overcome most of today's challenges across the world. A case study was carried out to determine the main constraints and how they can influence the decision-making process. The variety of urban pruning residues and their rate of generation, handling, storage, logistics, economic and environmental issues, institutional regulations for a small city in Southern Brazil were taken into consideration in the analysis. Pruning residues were sampled in the field, then handled, shredded, dried, specified, stored and burnt in a concurrent woodburning furnace for testing. The diagnostics of the constraints and the lab tests were summarized and organized in a framework that aimed to assess the energy valuation of pruning residues. Results show that with proper assessment tools, projects, biomass analyses and burning technology energy valuation of pruning residues can be feasible. • Energy valuation of biomass pruning residues is feasible given proper conditions. • A novel assessment framework provides routes to overcome most of today's challenges. • A case study of energy valuation of urban pruning biomass residue in Brazil showed feasible to generate 1 to 1.5 MWe. • Information and data of bulk density, moisture content, heating value, of residues of five urban tree species. • Estimate of opportunity costs of disposal of biomass pruning residues in landfills. [ABSTRACT FROM AUTHOR]

Although several studies have recognized the challenges brought about the high integration of Renewable Energy Sources (RES), research has yet to systematically investigate the effects of different levels of Energy Efficiency Measures (EEMs) on power systems with a high share of RES. The primary aim of this paper is to quantitatively evaluate the economic impact of different levels of energy efficiency investments in systems with a high share of RES, based on the case of Brazil. Our review analysis revealed a lack of understanding of how to calculate the Long-term Average Cost of Saved Electricity (LACoSE). Therefore, the methodological contribution of this research also lies in the proposition of a step-by-step procedure to estimate this variable. Findings of this study suggest that EEMs may result in a reduction in the expected new installed capacity between 1.9% and 10.3%, and from 0.4% to 4.3% for the total CO 2 emissions (for reductions in the final electricity demand varying from 1% to 5% respectively). This comes with a decrease in the overall system costs between 1.9% and 7.7%. The results provide further support for the hypothesis that the economic impacts of energy efficiency investments and its cost-effectiveness are affected by the share of RES in the power system and these type of measures may provide holistic benefits including not only economic advantages but also environmental and social improvements. The proposed methodology largely extends beyond the case addressed as it may provide valuable lessons for other electricity systems. • Cost-effectiveness of energy efficiency measures is assessed for a renewable system. • A methodology is proposed to calculate the Long-term Average Cost of Saved Electricity (LACoSE). • The economic benefits are positive for the power system evaluated. • Results are not highly influenced by the estimated LACoSE. • Findings would support the development of effective energy efficiency policies. [ABSTRACT FROM AUTHOR]

• Modeling interdependency between production and investment decisions is critical. • Investment in anaerobic digestion for vinasse treatment is advisable. • Second-generation ethanol via hydrolysis of surplus bagasse is still uncompetitive. • Long-term electricity contracting could hedge the risks accrued from investment. The past decades have seen a diversification of the sugarcane industry with the emergence of new technology to produce bioenergy from by-product and waste process streams. Given Brazil's ambitious goal of reducing green-house gas emissions by over 40% below 2005 levels by 2030, it is of paramount importance to develop reliable decision-making systems in order to stimulate investment in these low-carbon technologies. This paper seeks to develop a more accurate optimization model to inform risk-conscious investment decisions for bioenergy generation capacity in sugarcane mills. The main objective is for the model to enable a better understanding of how Brazilian government policies, such as the electricity price in the regulated market, may impact these investments, by taking into account the uncertainty in sugar, ethanol and spot electricity markets and the interdependency between production and investment decisions in terms of saleable product mix. The proposed methodology combines portfolio optimization theory with superstructure process modeling and it relies on simple surrogates derived from a detailed sugarcane plant simulator to retain computational tractability and enable scenario analysis. The case study of an existing sugarcane plant is used to demonstrate the methodology and illustrate how the model can assist decision-makers. In all of the scenarios assessed, the model recommends investment in extra bioelectricity capacity via the anaerobic digestion of vinasse but advises against investment in second-generation ethanol production via the hydrolysis of surplus bagasse. Furthermore, the decision to upgrade the cogeneration system with a condensation turbine is highly sensitive to the electricity price practiced in the regulated market, capacity constraints on the sugar-ethanol mix, and the accepted level of risk. Another key insight drawn from the case study is that recent market conditions have favored a production focused on the sugar business, making it challenging for policy-makers to create attractive scenarios for biofuels. Long-term electricity contracting appears to be the main hedging strategy for de-risking other products and investments in the sugarcane business, provided it is priced adequately. [ABSTRACT FROM AUTHOR]