Brazilian Generation Research Articles

ESTUDO DE VIABILIDADE TÉCNICA E ECONÔMICA DA IMPLEMENTAÇÃO DE UM SISTEMA FOTOVOLTAICO EM UMA RESIDÊNCIA EM PALMARES-PE

The growing attention to environmental and energy issues led to the search for renewable energy sources, which is gaining more and more space. In this context, photovoltaic solar energy is considered one of the most promising because it has advantages, such as ease of operation, possibility of integration in buildings, low level of proliferation during an operation and great potential for power generation in Brazil. Therefore, this work aims at a proposal to implement a photovoltaic system connected to the grid (On-grid) as an alternative to reduce the cost of energy consumption in a residence in the municipality of Palmares-PE. For the dimensioning of the photovoltaic system it was considered the monthly energy consumption of the residence and an irradiation of the place. Finally, a cost analysis was carried out to implement the system, which revealed that the use of this energy is economical and feasible. The solar generation capacity was projected at 6,27 kWp. The value of the project was R $ 32,049.98 and the payback period was 3 years and 8 months. Considering a Minimum Attractiveness Rate (TMA) of 6.5%, the NPV was R $ 225,707.88 and the Internal Rate of Return (IRR) of the system was a percentage of 43.55%.

The behaviour of a low voltage distribution network with crescent presence of photovoltaic generation and energy storage elements

This paper aims to examine the increasing integration of distributed energy resources in the low voltage distribution grid. Considering the current increasing of distributed photovoltaic generation in Brazil, there is a deterioration of specific indices related to power quality, such as overvoltage and voltage unbalance. In this sense, a survey of these problems, the severity assessment via simulation of a real system and the proposal of improvement in the associated indexes using energy storage devices are made. The resulting analyses contemplate both the current reality of growth in the distributed photovoltaic generation and the joint integration of these generators with energy storage systems, thus enabling a comparison of results focusing on the electricity grid impacts. The study has improved the network's operation, reducing the power quality aggravating factors and increasing the local consumption of the energy generated locally. The total losses on the original network were reduced by up to 52.6%, the voltage drop to 74.7% and the voltage rise was completely eliminated.

Economic feasibility study of ocean wave electricity generation in Brazil

Capturing wave power from the ocean is a renewable energy form which complements and diversifies energy grid sources. With its extensive coastline, Brazil has great potential for wave power generation. Economic viability is a key factor for energy generation projects, so the aim of this study is to conduct an economic assessment and Levelized Cost of Energy (LCOE) involved in implementation of wave energy converter devices to generate electricity in Brazil, given the various uncertainties associated with the parameters involved. To this end, the study was divided into two stages: an energy and economic analysis was carried out to implement wave energy converters in three regions of Brazil with two different converter devices; then, the levelized costs of electricity generation were calculated, given the multiple parameter variations involved, in order to observe the possible oscillations of these costs and the parameters responsible for the greatest impact. The results show that a high capacity factor has the best influence on LCOE values, making the ocean wave energy sales rate comparable with photovoltaic solar energy in Brazil. The study highlights the importance of investment in technology and development for ocean wave energy in order to see greater gains, thus making this type of project generation in Brazil greater possibility.

Increase in the irrigated area of sugarcane and its potential in the bioenergetic generation of Brazil

Sugarcane has alarge capacity for producing electricity using completely clean technology from a renewable source, contributing to environmental preservation. This study aimed to evaluate the increase in biomass resulting from the implementation of irrigation in Brazilian sugarcane plantations, estimate the potential for cogeneration, and calculate how much it will be possible to increase the Brazilian energy cogenerated with sugarcane bagasse and the impact on the Brazilian energy matrix. The increase in irrigation in the rainfed areas of Brazilian sugarcane plantations has substantial potential in increasing biomass for energy cogeneration. Considering an increase of 15% in the sugarcane plantation yields in rainfed areas achieved by the increase in irrigation, it leadsto a potential increase of 96.39 million tons of sugarcane and 26.80 million tons biomass produced. In the energy matrix, the potential impact is 1.42 GWh of cogenerated energy, which corresponds to a 12.47% increase in cogeneration in the sugar-energy sector and a 0.85% increase in Brazil's energy matrix. The expansion of the sugarcane irrigated area contributes to the increase in the production of bagasse and bioenergetic generation in Brazil.

Comparative analysis for distributed generation using ultra‐low head hydro, solar and wind energies

Brazil has one of the richest river basins in the world and an energy matrix based mostly on hydroelectric power. Current national policy is increasingly promoting renewable sources like wind power and solar photovoltaic power. Technologies used in generation energy via hydro, wind, and solar sources can be employed in decentralized generation. This study describes a turbine for hydro energetic use in flow sites with heads up to 2.5 (m). A hydrodynamic study was performed using computational fluid dynamics (CFD) analysis to evaluate the performance of this turbine. For this, a three-dimensional model of the turbine was considered, consisting of three computational domains, using periodicity to decrease the computational cost. The variation of the angular velocity and the volumetric flow were the boundary conditions. The turbulence model used was the shear stress transport. The draft tube geometry was modified according to the results of the CFD analysis. The efficiency and performance of the turbine improved from 79% to 80% as a result of this modification. A case study was conducted for a comparative financial analysis of the turbine proposed in this paper, with wind power and solar photovoltaic decentralized generation in Brazil.

The impacts of the construction of hydroelectrics on indigenous communities. Displacement, division and pilgrimage among The Tuxá peoples of Bahia state, Brazil

Due to the construction of the Itaparica Hydroelectric Plant in 1988, the Tuxás were displaced from their lands and resettled, generating internal conflicts and various socio-environmental impacts. Historically dedicated to agriculture and fishing, the resettlement of Tuxás changed their livelihoods, affecting nutrition and their relationship with their livelihoods. For those who still have access to fishing on the São Francisco River, the availability of fish has been reduced as a result of water polluting eutrophication, due to the disposal of sewage and fertilizers. The results include new elements, often disregarded, to reexplore the socio-environmental trade-offs of the installation of hydroelectric plants in Brazil. He concludes by proposing alternative perspectives (mainly from the bottom up), to rethink the delicate balance between economic progress driven by energy generation in Brazil and also the negative impact on the livelihood of the country's most vulnerable communities.

Theoretical and technical assessment of agroforestry residue potential for electricity generation in Brazil towards 2050

Bioeconomy, as a key strategic innovation pillar, supports energy transition and involves biomass resource assessment and its application. Biomass has an enormous potential to fulfil the domestic energy demand in Brazil. Hence, this study aims to quantify the theoretical, technical and techno-economic potential of agricultural and forestry residues to generate electricity via thermochemical processes in Brazil for the 2018–2050 timeframe. The analysis was carried out via an integrated approach, according to statistical reports and literature data. Conversion technologies for the estimation of technical potential consist of organic rankine cycle, combustion with conventional rankine cycle and gasification with an internal combustion engine. The results showed that Brazil’s theoretical potential is 7185.39 PJ and 16,708.12 PJ in 2018 and 2050. The technical potential in 2018 is 1795.16 PJ, generating 71,236.47 MWe, while the potential in 2050 is projected as 5771.49.4 PJ providing 229,027.31 MWe. The main restrictions are dispersed distribution of biomass over a large area, supply costs, and low efficiencies for energy conversion. Therefore, the techno-economic potential is around 19,704.01 MWe and 63,348.95 MWe for 2018 and 2050. The north region has the lowest electricity generation potential, while the southeast region takes a prominent position to generate electricity mainly from sugarcane residues. Levelized costs of electricity values varied from 10.532 to 15.507 US$/MWh for 2018 and from 7.320 to 13.002 US$/MWh for 2050, which highly influenced by the biomass price. The results of this study can support policy-making towards future planning on Brazilian bioenergy.

Current Status and Perspectives of the Electric Sector in Brazil

Brazils demand for electricity has been increasing in recent years and most of the electric energy is generated by hydroelectric plants. The country has the most renewable electrical matrix in the world. Besides, it has one of largest installed capacities for harnessing energy from hydraulic power. This work aims to present a perspective of electric power generation in Brazil, pointing to the expected development of electricity generation in the regions, the cost of operation, CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> emissions and the energy exchange between those regions for the extreme demand situations expected to occur in 2022 and 2031. The results for the future scenarios were obtained through simulation using the ANAREDE program. Operating cost and CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> emissions were calculated based on referenced average indexes. The results indicate that for 2031 the active electric power generation tends to grow from 20.7 % to 25.9 %, whereas the active load will grow an average 24.7 %. The share of renewable energy in the generation of electricity tends to increase in 2022, between 86.6 % and 94.3 %, while for 2031, the trend is for stability, around 82.6 % and 84.7 %. The operating cost per MWh in the National Interconnected System (SIN) tends to decrease in the years studied. The CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> emission rates obtained ranged from 82.6 Kg CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> MWh <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1 </sup> to 92 Kg CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> MWh <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . The exchange of electricity between regions was similar to that found in recent years, except between the Southeast / Midwest and the Northeast.

Land-use impacts of Brazilian wind power expansion

While wind power is a low-carbon renewable energy technology with relatively little land footprint, the necessary infrastructure expansion still has land-related environmental impacts. Brazil has seen more than a ten-fold increase in wind power capacity in the last decade. However, little is known about these impacts of wind power generation in Brazil compared to other world regions, although Brazilian wind power infrastructure is concentrated in the least protected ecosystems that are prone to degradation, desertification and species extinction. This study focuses on land-use impacts of past wind power generation development in four Brazilian federal states, covering 80% of the country’s installed capacity. We assessed their spatial installation patterns, associated land-use and land cover change in the period before installation until 2018, and potential alternative installation locations, using a detailed wind turbine location database in combination with a high-resolution land-use and land cover map. In contrast to wind parks built in Europe, we found that 62% of the studied wind park area was covered by native vegetation and coastal sands. Overall, 3.2% of the total wind cluster area was converted from native vegetation to anthropogenic use. Wind parks installed mainly on native vegetation, on average, underwent higher land-use change compared to other wind parks. As Brazil intends to more than double its current wind power capacities by 2029, we explored possibilities to reduce environmental risks due to wind power expansion. We showed that this is feasible by integrating wind parks into human-altered areas, as sufficient wind resources there are available.

Rice husk energy production in Brazil: An economic and energy extensive analysis

Abstract Brazil is one of the most prominent rice producing nations in the world, with an annual output of more than 11 million tons. Rice husk is one of the main byproducts in rice processing. Large volumes of this residue are generated when processing the grains. This byproduct has great calorific value, and thus possesses significant potential for electrical energy generation. This study presents a thorough economic and energy analysis of rice husk energy production on a regional and national scale in Brazil. Furthermore, economic viability analysis was assessed through a variety of scenarios. Data were collected from rice cultivation areas throughout the country, including every Brazilian city where rice is grown, in order to identify the minimum planting area to enable power generation from rice husks. Then, economically viable energy potential was calculated. The minimum area for rice cultivation in order to guarantee economic viability varied from 700 to 26,700 ha, depending on the economic scenario. Levelized costs of electricity and net present values varied from 53.71 to 164.94 USD/MWh, with an average of 112.2 USD/MWh, and −1 to 7.3 106 USD, being highly influenced by the planting area. In more optimistic scenarios, the viable energy potential of this biomass in Brazil can exceed 2.5 TWh/year, which represents around 5% of the country’s total bioenergy production. Such results demonstrate that energy generation from rice husks can be an important resource to increase bioenergy generation in Brazil. This tendency was particularly pronounced in the South, where rice production is more concentrated.

Of democratic governance and revenue: Participatory institutions and tax generation in Brazil

AbstractGovernments around the world often struggle to collect tax revenues, thus undermining their ability to build functioning states, deliver basic public goods, and improve human development. This problem is especially acute in the Global South. Within the broader context of representative democracy, many local governments increasingly adopt participatory institutions in the hope that they will improve government responsiveness, service delivery, and their electoral opportunities. We address gaps in knowledge on participatory institutions and tax collection by asking two critical questions: to what extent (if any) do these reforms improve local governance? And how would we know? We draw from an original database on Brazilian Municipalities that includes fiscal, political, and state capacity variables. We find that municipal governments that adopt participatory institutions generate higher tax revenues than comparable governments without these institutions. This article thus provides a novel, thorough assessment of how new participatory institutions affect governance and revenue‐generation.

Impact of the COVID-19 pandemic on environmental awareness, sustainable consumption and social responsibility: Evidence from generations in Brazil and Portugal

The COVID-19 Pandemic has become a major public health concern worldwide, which can impact environmental sustainability and social responsibility, as well as people’s quality of life. In this context, environmental awareness, sustainable consumption and social actions of people have been effectively changed, as a period of quarantine, social isolation and health crisis caused by Pandemic has been experienced. This study aims to analyze the impact of the COVID-19 Pandemic on environmental awareness, sustainable consumption and social responsibility, in the perception of Baby Boomers, X and Y generations, residents in Brazil and Portugal. The method used was quantitative research, of a descriptive character, through a survey applied to 3236 people, which was analyzed with the use of Structural Equation Modeling. The results indicate that COVID-19 Pandemic is an important vector in people’s behavioral change, which reflects on environmental sustainability and social responsibility. It is noteworthy that the impact of the COVID-19 Pandemic had a greater influence on sustainable consumption, followed by environmental awareness, and to a lesser extent, on social responsibility. There was also greater relevance in Portugal, as well as the perception of the Baby Boomers generation. This study also provides a framework such as metrics to measure a transformational event, which is the COVID-19 Pandemic in socio-environmental aspects and conscious consumption.

Analysis of financial and economic feasibility of the use of vinasse for electricity generation in Brazil

Abstract In view of the growing importance of distributed generation, the pluralization of the energy matrix close to large consumption centers has become necessary. In this sense, the energy sector can contribute to electricity generation using waste products such as vinasse, the most relevant in terms of volume and polluting capacity. The general objective of this article is to analyze the economic feasibility of using vinasse for electricity generation, and as a specific objective, to identify the viable price range of MWh in free and regulated energy environments and the productive capacity of plants for this type of investment. The methodology used was quantitative research, based on the cost structure of a biodigester IC internal combustion engine with 38% yield and vinasse logistics according to the production capacity of autonomous plants of 100 m3, 1,000 m3, and 3,000 m3ethanol/day for scenarios with and without tax exemptions for a price range between US$ 26.04 and US$ 130.20/MWh. The analysis shows that the use of vinasse for electricity generation is restricted to medium and large producers. Furthermore, the price of MWh is more relevant than the tax exemption for the feasibility of this type of project. This corroborates the constant requests from the sugar-energy sector to hold exclusive electricity auctions for biomass, given its cost structure and its social, economic, and environmental externalities.

Combining wind and solar energy sources: Potential for hybrid power generation in Brazil

Wind and solar energy have stood out in recent years because of the growth of global installed capacity. This work aims to present wind and solar photovoltaic energy development and its regulatory framework in Brazil, and demonstrate the potential for centralized hybrid generation. Official studies, research reports, and thematic maps were consulted, and two pilot hybrid plants were studied. Results indicate that there is great potential for centralized hybrid generation in the Brazilian Northeast region. However, there is a need for the regulatory framework to evolve to enable its development.

Analysis of financial and economic feasibility of the use of vinasse for electricity generation in Brazil

Abstract In view of the growing importance of distributed generation, the pluralization of the energy matrix close to large consumption centers has become necessary. In this sense, the energy sector can contribute to electricity generation using waste products such as vinasse, the most relevant in terms of volume and polluting capacity. The general objective of this article is to analyze the economic feasibility of using vinasse for electricity generation, and as a specific objective, to identify the viable price range of MWh in free and regulated energy environments and the productive capacity of plants for this type of investment. The methodology used was quantitative research, based on the cost structure of a biodigester IC internal combustion engine with 38% yield and vinasse logistics according to the production capacity of autonomous plants of 100 m3, 1,000 m3, and 3,000 m3ethanol/day for scenarios with and without tax exemptions for a price range between US$ 26.04 and US$ 130.20/MWh. The analysis shows that the use of vinasse for electricity generation is restricted to medium and large producers. Furthermore, the price of MWh is more relevant than the tax exemption for the feasibility of this type of project. This corroborates the constant requests from the sugar-energy sector to hold exclusive electricity auctions for biomass, given its cost structure and its social, economic, and environmental externalities.

Potential impacts of vinasse biogas replacing fossil oil for power generation, natural gas, and increasing sugarcane energy in Brazil

This paper presents the potential of biogas from anaerobic digestion of vinasse and its impact in different contexts. The use of vinasse biogas (VBG) for power generation is evaluated and the potential of this energy source is compared with fossil oil power plants in terms of energy, costs and greenhouse gases (GHG) emissions in Brazil, suggesting a program where the most expensive oil power plants are replaced by biogas plants with benefits in all aspects. Secondly, the use of vinasse biomethane (VBM) to replace natural gas (NG) in the state of São Paulo is examined, presenting an incentive program that could make this alternative fuel feasible even in smaller scale plants with minimal impact on NG costs in this state, while providing considerable emission reduction. The impact of VBG considering the increase in ethanol production over the next ten years is also evaluated, showing that substantial additional energy can be obtained and larger amounts of fossil fuels can be replaced. By crossing vinasse biogas potential with selected fossil fuels demand, the article brings insights to help the transition to a low-carbon society in a novel approach. The conclusions are that VBG and VBM can provide great benefits, such as USD 1 billion/year cost reductions and 6.7 million tons CO2e/year emissions avoided by replacing fossil oil by biogas in power generation in Brazil and 3.2 million tons CO2e/year avoided with biomethane replacing natural gas in the state of São Paulo, which, with specific programs and policies, could be achieved.

Forecasting Hierarchical Time Series in Power Generation

Academic attention is being paid to the study of hierarchical time series. Especially in the electrical sector, there are several applications in which information can be organized into a hierarchical structure. The present study analyzed hourly power generation in Brazil (2018–2020), grouped according to each of the electrical subsystems and their respective sources of generating energy. The objective was to calculate the accuracy of the main measures of aggregating and disaggregating the forecasts of the Autoregressive Integrated Moving Average (ARIMA) and Error, Trend, Seasonal (ETS) models. Specifically, the following hierarchical approaches were analyzed: (i) bottom-up (BU), (ii) top-down (TD), and (iii) optimal reconciliation. The optimal reconciliation models showed the best mean performance, considering the primary predictive windows. It was also found that energy forecasts in the South subsystem presented greater inaccuracy compared to the others, which signals the need for individualized models for this subsystem.

The complementary nature between wind and photovoltaic generation in Brazil and the role of energy storage in utility-scale hybrid 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.

Zoning for exploration of wind energy in Ceará with the use of geographic information systems (GIS) and multicriteria analysis

Wind energy has many advantages compared to traditional energies, from the ability to reduce the use of fossil fuels as well as the possibility of creating jobs in the areas where the projects are installed. The growth of this type of generation in Brazil has been driven by strong investor interest due to the characteristics of the country's winds, mainly from the Northeast. The winds are strong, stable and most of the time follow the same direction, characteristics that make windfarms in the Northeast region have high levels of capacity factor. By evaluating the data from the wind farms installed in Ceará, it can be observed that they present one of the best capacity factors in Brazil and have values above the world average. This indicates and reinforces the viability of implementing this type of energy generation in the area. It was verified that there are studies about wind conditions but there are no studies that correlate this information with the infrastructure conditions of the State. Therefore, the objective of the present work is to identify the appropriate areas for the allocation and use of wind energy in the State of Ceará through the integration of Geographic Information Systems (GIS) tools and multicriteria analysis for decision making.

Pumped Hydroelectric Energy Storage in Brazil: Challenges and Opportunities

Motivated by growing concerns about the environment and the rising price of fossil fuels in recent years, many countries have started to diversify their energy sources, opting for renewables whenever feasible. Brazil, a country with a predominance of hydroelectric generation, has also experienced a greater participation of other renewable sources, such as wind, solar and biomass. However, even though they contribute for a lower dependence on water and fossil fuels for energy generation, their intermittence lead to an increase of operational complexity and may threaten the country’s energy security. As an emerging economy with growing energy needs, the challenge now in Brazil is to identify ways to ensure efficient energy supply, compatible with demand and mindful of environmental issues. In this context, this work presents a compilation of the main studies and surveys related to Pumped Hydroelectric Energy Storage (PHES), while seeking to contribute in finding ways to reduce the unpredictability of renewable sources generation. Furthermore, the aim is to increase energy security in times of drought, especially when the inter-regional, seasonal and multimodal complementarity of energy generation in Brazil fails to avoid energy deficits. The methodology used draws upon a bibliographical review of the current PHES scenarios in Brazil and in the world. Advantages and opportunities of this type of energy storage are assessed at the national level, together with a presentation of the challenges faced by the implementation of this model in Brazil. Finally, we discuss the main challenges and present some suggestions for future work on this subject. A post-publication change was made to this article on 3 Jul 2020 to correct an author name.