Hydroelectric Plant Research Articles

Fatores de Risco ao Patrimônio Cultural do Estado de Mato Grosso

The objective of this article is to identify the risk factors that most affect the intangible, archaeological and architectural-landscape heritage of Mato Grosso, from the perspective of managers of public institutions linked to its preservation and conservation. The research started from a survey (questionnaire) of participants' opinions regarding risk factors that affect cultural heritage, with subsequent quantification and qualitative analysis (data tabulation) and quantitative analysis (assessment of reliability and internal consistency using a statistical instrument). The most common risks for architectural-landscape heritage are Abandonment (72%, Social dimension), Mismanagement (67%) and Successive reforms and renovations (67%), both in the Governance dimension; in the Environmental dimension they are Fires (44%) and Construction of various projects (44%). For archaeological heritage, the most common risk factors in the Environmental dimension are Construction of hydroelectric plants, dams and similar (50%), Intensive crops in sensitive areas (50%), Livestock in sensitive areas (50%) and Deforestation (50%). The most common risk factors for intangible heritage are: in the Governance dimension - Mismanagement (44%) and, in the Environmental dimension: Livestock in sensitive areas (50%), Deforestation (56%) and Fires (50%). Cronbach's Alpha values ​​were 0.965 for intangible heritage, 0.962 for archaeological heritage and 0.97 for architectural-landscape heritage, concluding that the results obtained are reliable.

A NARRATIVA COLONIAL PARA IMPLANTAÇÃO DE USINAS HIDRELÉTRICAS NO AMAPÁ

In the Amazon, the persistence of a colonial project, which triggered the appropriation of the territory for the implementation of hydroelectric plants, has been reproducing damage and disasters and causing, for decades, a series of socio-environmental conflicts. From this perspective, the objective of this article is to analyze the dynamics of the implementation of mitigation and compensation measures, as an instrument of Environmental Policy, in communities of artisanal fishermen and family farmers in the Brazilian Amazon, specifically in the State of Amapá, which are subject to disasters caused by hydroelectric dams on the Araguari River. In the conjuncture, even in the face of the persistence of social and environmental damages and disasters, there is a discourse of the inevitability of hydroelectric plants, under the allegation that the consequences can be mitigated or compensated. However, guided by Decolonial Epistemology, after documentary analysis of Ten-Year Energy Expansion Plans (2006-2021), public civil actions, TACs and interviews, which comprise information collected from fishermen and family farmers on the Araguari River, State of Amapá, it was found that the implementation of mitigating and compensatory measures proved to be illusory. From a participatory research, it was possible to observe the destructuring of an environment that was the basis for the survival of secular communities. In view of this, it is necessary to break with this exclusionary and unequal rationality through resistance movements and to embark on an epistemological disobedience necessary to confront the relations of domination and power present in capitalist projects, such as hydroelectric plants.

AI-driven predictive maintenance and optimization of renewable energy systems for enhanced operational efficiency and longevity

The rapid growth of renewable energy systems necessitates advanced strategies for maintenance and optimization to ensure long-term operational efficiency and sustainability. Traditional approaches often fall short in predicting failures and optimizing performance across diverse and dynamic renewable energy infrastructures. This study investigates the application of artificial intelligence (AI) techniques for predictive maintenance and optimization of renewable energy systems, with the aim of enhancing operational efficiency and extending system longevity. We employ a combination of machine learning algorithms, including deep neural networks and reinforcement learning, to develop predictive models and optimization strategies. These models are trained on large-scale datasets collected from operational wind farms, solar installations, and hydroelectric plants. Our results demonstrate that AI-driven approaches can predict equipment failures with 92% accuracy, reducing unplanned downtime by 35% compared to traditional methods. Moreover, AI-optimized operational parameters improved overall energy output by 8.5% across the studied systems. The proposed framework also showed adaptability to various environmental conditions and system configurations, suggesting broad applicability across the renewable energy sector. This research underscores the significant potential of AI in revolutionizing maintenance practices and operational strategies in renewable energy systems, paving the way for more reliable, efficient, and sustainable clean energy production.

Temporal variation of mercury levels in fish, soil, and sediments in an Amazon reservoir: insights from 35years of river impoundment in Pará State, Brazil.

The increase of mercury (Hg) concentrations in abiotic and biotic compartments of aquatic ecosystems following the river impoundment for building a hydroelectric reservoir is one of many environmental and social impacts that the construction of hydroelectric plants can trigger. Yet, long-term studies in Amazon reservoirs are still scarce. The present study aimed to understand the effects of dam impoundment in THg concentrations in an Amazon reservoir up to 35years of its creation. On March 2019 (35th year after filling), samples of fish, soil, and sediments were collected in the Tucuruí reservoir. Total mercury (THg) concentrations were determinate in those samples and compared with data extract from previous studies referring to the 6th, 16th and 18th years after the reservoir filling. Fish from different guilds at the 6th year after filling the Tucuruí reservoir had high THg concentrations, and those decreased in the 16th and 18th years, then the concentrations increased again in the 35th year after filling. For soils and sediments, a decline in THg concentrations was observed. These results differ from previous studies that predicted that Hg concentrations in fish would return to natural concentrations within 30years in temperate zones and no decline of THg concentrations would be observed for Amazonian reservoirs. The Tocantins river drainage basin has been subjected to multiple anthropic disturbances and land use changes over the past decades, such as the implementation of new hydroelectric plants, deforestation, and fires, which can explain our observations. This study contributes valuable long-term insights into the dynamics of Hg concentrations in an Amazonian reservoir, highlighting the complex interactions between environmental changes and Hg accumulation over decades.

Relationship of mercury bioaccumulation with seasonality and feeding habits of fish species caught upstream and downstream of the Curuá-Una hydroelectric dam in the Brazilian Amazon.

Hydroelectric plants impact the dynamics of mercury accumulation and transfer to aquatic ecosystems and organisms. This study aimed to determine total mercury (THg) concentration in filtered water, aquatic macrophytes, and fish and assess the influence of fluvial regime (low-water, rising-water, and high-water) and the feeding habits of fish species caught upstream and downstream of the Curuá-Una hydroelectric dam in the Brazilian Amazon. THg levels were determined by cold-vapor atomic fluorescence spectrometry. THg concentration in filtered water was higher (5.3-11.2 ng L-1) during the low-water period. THg concentration in fish ranged from 0.075 to 1.160 µg g-1 in specimens caught downstream and from 0.014 to 1.036 µg g-1 in specimens caught upstream of the dam. The highest THg concentrations were detected in specimens of the piscivorous species Acestrorhynchus falcirostris (1.161 µg g-1) caught at downstream sites. There were significant correlations of THg concentration with the trophic level (Analysis of Variance; p ≤ 0.001) of fish species and fluvial regime (Analysis of Variance; p ≤ 0.001). The macrophyte Utricularia foliosa contained the highest THg levels in leaf tissues in the low-water period (71.4 µg g-1). It is concluded that THg concentration varies between fish trophic levels and fluvial regimes. Macrophytes contribute to enhancing mercury transfer and availability along the aquatic trophic chain.

A Mesoscopic Approach for the Numerical Simulation of a Mass Concrete Structure Construction Using Post-Cooling Systems

This study introduces an innovative numerical approach to simulate the construction of large concrete structures incorporating post-cooling systems employing the finite element method (FEM). The proposed methodology integrates critical construction parameters, including temperature control mechanisms, while accounting for concrete hydration and environmental conditions. Compared to traditional discrete models, this approach provides similar accuracy with substantially reduced computational costs, enhancing predictive capabilities in the thermal analysis of mass concrete. The method was applied to simulate the construction of a water intake pillar at the Tocoma hydroelectric plant in Venezuela, where the simulated results closely matched in situ temperature measurements. The findings highlight the method’s efficiency and accuracy in simulating post-cooling systems, offering a practical solution for improving the safety and cost-effectiveness in large-scale concrete construction projects.

Hydrological and morphological responses in the São Francisco River Basin (Northeast Brazil) resulting from river damming and climate changes in a tropical region

AbstractThe São Francisco River in Northeast Brazil has seen hydrological and morphological changes due to extensive damming and climate change over the past century. In this study, we examine the influence of human activities and natural fluctuations in precipitation on the hydrological patterns of the basin and the morphological responses of the lower course of the river (LOW‐SF) to these alterations over a span of several decades. The findings indicate a decrease in water release by 41% from 1995 to 2013 and 54% from 2013 to 2018, solely attributed to human actions. Furthermore, the operation of the reservoirs of the large dams resulted in a reduction in hydrological seasonality. The changing hydrological regime caused morphological changes that resulted in an expansion of the exposed subaerial fluvial bars in the LOW‐SF and a reduction in channel width. As a result, the abandonment of small secondary channels occurred, leading to the cessation of inundation in previously buried elevated portions of bars, even during certain seasons. Another important factor was the spread of morphological changes in the LOW‐SF, which started from the areas farthest from the last dam in the series of large dams, the Xingó Dam, and spread to the nearby regions. This is due to the lack of major tributaries in the semiarid region of the LOW‐SF. The integrated assessment presented in this study illustrates both natural and anthropogenic influences. Moreover, in light of projected declines in precipitation, it is anticipated that natural phenomena could result in a substantial 73% decrease in water flow by the mid‐20th century. This climatic scenario will lead to increased utilization of hydroelectric plants and more stringent control of water flow downstream of the dam cascade, intensifying the already documented adverse effects and posing the possibility of novel morphological adaptations.

Natural gas as a generating source in the diversification of the Brazilian electric matrix

Energy consumption grows annually, requiring an increase in the production and distribution standards of available energy sources. One of the main energy consumptions is linked to the electricity sector, which is globally dependent on fossil fuels such as oil and coal. In Brazil, more than 60% of electricity consumption comes from hydroelectric plants, and the lack of variability in generating sources generates instability and energy insecurity in the country. In this sense, it is necessary to evaluate an alternative source of electricity that can work together with hydroelectric plants and guarantee the stability of generation. Natural gas presents itself as an alternative, as it is a safe source and less aggressive to the environment when compared to other non-renewable sources. Through data collection and bibliographic research on proven reserves, processing capacity, and distribution of natural gas, this work analyzed the Brazilian potential for the use of natural gas and the biggest gaps in the sector. The results showed that, despite the great potential in proven natural gas reserves, Brazil is stagnant in its processing and distribution capacity. In addition, there are challenges related to high rates and taxes on the use of natural gas.

Effect of weathering on the stability of rock slope at a water intake canal of Simplicio Hydroelectric Power Plant

Rock and joint alteration leads to modifications in their properties, resulting in a reduction of rock mass strength and consequently a decrease in the safety of engineering structures. The alteration process changes the material and alters its geomechanical behavior. This research presents the studies conducted to evaluate the mechanical behavior of rock joints in the gneiss massifs that make up the hydraulic circuit of the Simplicio Hydroelectric Plant due to their alteration. Compilation and analysis of data from previous research were carried out to parameterize the joints at different levels of alteration. Deterministic stability analyses showed that the alteration process of gneiss joints can significantly reduce the slope safety factor by up to half of its initial value. Furthermore, probabilistic analyses revealed an increase in failure probability of approximately 10% among the studied alteration classes. The results underscore the importance of assessing the level of joint alteration in engineering projects.

Environmental factors affecting the distribution of Spongillidae (Porifera) in an artificial channel (in north-western Italy)

The hydrographic network of the upper Po Valley (NW Italy) is characterized by the presence of numerous hydroelectric plants, often powered by artificial channels. These man-made water courses, which range from a few hundred meters to several kilometers in length, are used to convey water from the rivers to the electricity production plant. Power canals are usually characterized by concrete banks and bottoms, a geometric profile, and the absence of riparian vegetation so that they host peculiar invertebrate communities, often extremely well adapted to life in a completely artificial habitat. Sponges are an often little considered component of the freshwater macroinvertebrate fauna, whose functions and role within communities can be of considerable interest. These sessile, filter-feeding organisms can colonize artificial channels, but little is known about the local environmental characteristics that influence their distribution. In this study, we investigated the distribution of a freshwater sponge family Spongillidae, in a 4.5 km long artificial channel in Rocca Grimalda (Alessandria, NW Italy). A total of 863 specimens were localized and measured, and selected environmental characteristics were recorded. Results suggested that the distribution of sponges depends mainly on the lighting rather than the type of substrate or other local factors, so that this taxon is well-suited to colonizing artificial environments with good water quality conditions.

Collective Rural Resettlement: the Vulnerabilities of Families Affected by a Hydroelectric Dam in Southern Brazil

Objective: To evaluate the ways in which affected families cope with health vulnerabilities and environmental changes after compulsory displacement, considering the Rural Collective Resettlement (RCC) service modality. Theoretical Framework: The vulnerability in health and environment proposed by José Ricardo Ayres is observed in the affected population as the chance of people being exposed to illness, taking into account the environment, individual, social and health service aspects. Method: 11 questionnaires were administered to those affected by the hydroelectric plant, who were served by the RCC modality. Results and Discussion: Subjective aspects involving the compulsory displacement of the affected population, such as the networks of social, cultural and neighborhood relations, are supplanted by the prospect of economic gains for the municipalities, based on the supposed regional development caused by the movement brought about by the start of construction and, later, by the payment of royalties to the affected municipalities. However, the losses due to profound changes, especially for the population affected, the compulsory displacement and, with it, the reduction in the local population and, consequently, the economy, are not properly accounted for. Research Implications: The RCCs are the least incentivized and most time-consuming form of care Originality/Value: The sense of belonging and identification as a community, the promotion of collective work and the organization of the health and education care network have contributed to making the health and environmental vulnerability caused by the hydroelectric dam less significant.

The role of hydropower in decarbonisation scenarios

An increased penetration of renewable energy sources is essential for the energy transition. A major role will be played by wind and solar, as they are widely available. Hydropower is another crucial resource, currently covering large shares of power generation (e.g., Norway, Italy, Brazil). Despite little expected growth, in a context of increasing electrification, improved integration of hydropower can play a critical role thanks to programmable operation. This work addresses the modelling of hydropower flexibility in energy system models and analyses the impact of hydropower operation on CO2 emission-constrained scenarios. To implement the study, a detailed dataset of the Italian programmable hydroelectric plants is created, using open-source information, covering location, rated power, and storage capacity. Inflow timeseries are derived from historical operational data. These new sets of data are employed in OMNI-ES (a multi-node, multi-sector, and multi-vector energy system model) to study optimal configurations and operation of the Italian energy system in decarbonisation scenarios, such as net-zero-CO2 and Fit-for-55 targets. Considering different operational strategies and multiple historical reference years (impacting the inflow), results demonstrate significant changes in hydropower behaviour and highlight its relevance as zero-carbon resource in terms of both power and energy output, influencing the installation of other technologies.

Brazilian Cerrado and Conservation Units

Objective: The present study aims to demonstrate the importance of the Brazilian cerrado, and its preservation through Conservation Units (UC’S). Theoretical Framework: The cerrado is home to one of the main components of Brazilian fauna and flora and is considered one of the twenty-five global hotspots. Even though it is not a cataloged biome, it covers around two million square kilometers, second in size only to the Amazon forests among South American biomes (COLLI et al. 2020). It is filled with several Conservation Units, divided into two groups: Integral Protection Units and Sustainable Use Units, which are complementary components of the cerrado, important for protecting biodiversity. Despite its importance as a natural environmental instrument, the cerrado has already lost approximately 56% of its coverage (KLINK; MACHADO, 2005). Method: The methodology adopted for this research comprises a comprehensive analysis, instrumented by a deductive approach and bibliographic and documentary procedures. Results and discussion: The results demonstrate that UC'S, especially those with full protection, are important strategies for preserving biodiversity and ecosystems, in addition to stopping the expansion of activities that degrade the environment, such as agricultural expansion, mining, urbanization and construction of hydroelectric plants. Research Implications: The practical and theoretical implications of this research are discussed, providing insights into how cerrado areas still seek recognition, appreciation, protection and conservation. Originality/Value: This study contributes to the literature and draws attention, especially from the academic community, to the need to create new Conservation Units and effectively maintain those already created.

ESTUDIO DE DIFERENTES ALTERNATIVAS DE FUNCIONAMIENTO DE LOS GRUPOS EN LAS CENTRALES ELÉCTRICAS DE CANARIAS

Island electricity systems aim to adapt to the environmental expectations established by the European framework. For this reason, it is necessary to increase efforts to increase the penetration of renewables and optimize energy production. An extensive preliminary research study has been carried out on the current production system, its variables and its conditioning factors, with which a series of operating alternatives have been obtained that will optimize the energy production system through combustion technology (non-renewables) and combine them with the production of energy through renewable sources. renewables, complying both in dynamic response, security, scaling and integration with such systems, in terms of efficiency and power. The reduction of greenhouse gas emissions and the penetration of these renewable energies in the island's electricity systems will be increased. As has been proven in the research background, the usually established combination of power producing equipment is not the best to reduce pollution, and there are other possible combinations with better results. The study methodology followed leads to take measures based on: a) changing the type of fuel in the equipment that allows it, b) using the combination of less pollutant producing equipment with response capacity and c) considering the integration and incorporation of the pumped hydroelectric electric storage plant (PHES) "Chira-Soria" into Gran Canaria's electrical system. The different measures contribute to the improvement in the reduction of greenhouse gases (GHG) in a convincing way. Keywords: Isolated power system, Generation expansion planning, Energy transition, Insular electrical systems (IES), Energy policy, Canary Islands, Renewable energy, Pumped hydroelectric storage plant (PHES).

Artificial Neural Network Model to Predict the Factor of Safety in Earth Dams Subjected to Rapid Drawdown

Rapid drawdown has been identified as one of the most frequent causes of slope failures due to the effects associated with drought and operational changes when incorporating hydroelectric plants, which influence the filling level of earth dams. The main goal of this research is to obtain predictive models based on Artificial Neural Networks that return the factor of safety of the upstream slope in homogeneous earth dams in the face of the effect of rapid drawdown. Three geometries and 40 soils were defined to form the embankment, from which hybrid numerical models of transient water flow with unsaturated soils were built, considering three discharge speeds. From these results, a database was built to develop the predictive models, by means of the KNIME program and an algorithm based on Artificial Neural Networks. The behavior of the factor of safety as a function of time is also analyzed to establish its recovery intervals. Main results show that the minimum factor of safety is obtained between 52 % and 88 % of the total drawdown time. Regarding the predictive models, the adjusted R2 determination coefficients were greater than 95 % in all cases and the errors remained below 10 %. This demonstrates a high effectiveness of this algorithm and the validity of its application to geotechnical problems.

Techno-economic assessment of the Dethridge waterwheel under sluice gates in a novel design for pico hydropower generation

The world is increasingly shifting toward low-head hydropower as a sustainable form of renewable energy in response to the negative socioeconomic impacts of large hydroelectric plants. In this context, the article presents a novel design involving retrofitting the gates of existing dam structures with Dethridge waterwheel technology. This innovative solution installs the wheel under the gate to harvest the untapped potential energy resulting from the head difference at these already-existing facilities while simultaneously reducing the need for costly civil work and preventing new installations in freshwater systems. The El-Reah El-Tawfiqy barrage in Egypt served as the model case study for evaluating the implementation of the proposed design. According to the results, the plant's levelized cost is 29 USD/MWh, less expensive than traditional hydropower projects and achieves grid parity. With an estimated 140 MWh of electricity produced annually, the project is expected to cut around 1460 tons of CO2 equivalent over its 25-year lifespan. This study includes several novelties, including modifying hydraulic structure gates for pico power generation. Additionally, a thorough numerical analysis was performed to estimate the output power instead of relying on theoretical approaches for the economic viability study. These results can guide policymakers and stakeholders in implementing affordable and sustainable renewable energy solutions.

Modeling of Brazilian Wind Power Generation Capacity: A Multivariate Analysis with Neural Networks

Over the last twenty years, Brazil has experienced significant changes in its electric energy matrix, notably with the expansion of wind and solar energy sources. In the early 2000s, hydroelectric plants with a capacity of 70 gigawatts (GW) were responsible for generating 90% of the country's electricity, while solar and wind sources contributed merely 1%. Today, the scenario has evolved, with wind and solar energy comprising approximately 25% of the national generation, indicating a departure from the previous hydro-dominated matrix. This research aims to apply specific types of neural networks to multivariate data to forecast Brazil's wind power generation capacity, providing insight into the potential for future energy strategies. This research contributes as a as a decision support tool contemplating relevant information for analysts, researchers, and participants in the renewable energy market. The monetary volume destined to import key components of the wind, considering specific time lags, was utilized to forecast the Installed capacity of the wind farms in Brazil. The Toda-Yamamoto Causality Tests revealed unidirectional Granger causality in the sense of the Import variable for the Brazilian Installed Capacity variable for wind energy production. Another result obtained was the finding that the variable that matters most in the multivariate configuration of the Neural Network is the variation in Installed Capacity in megawatts, followed by the import volume of wind energy components, which exhibited critical lags at 3 and 6 months.

Evaluation of renewable energy technologies in Colombia: comparative evaluation using TOPSIS and TOPSIS fuzzy metaheuristic models

The study investigates the weighting and hierarchization of renewable energy sources in specific geographical regions of Colombia using the TOPSIS and Diffuse TOPSIS metaheuristic models. 5 regions were analyzed, two of them with different scenarios: Caribbean 1 and 2, Pacific 1 and 2, Andean, Amazonian and Orinoquia. The results reveal significant differences in the evaluation of technologies between the two models. In the Caribbean 1, Diffuse TOPSIS gave a higher score to Solar Photovoltaics, while TOPSIS favored Hydropower. In the Caribbean 2, Solar Photovoltaic obtained similar scores in both models, but Wind was rated better by TOPSIS. In the Pacific Region 1, Biomass and large-scale Hydropower led according to both models. In the Pacific 2, Solar Photovoltaic was better evaluated by TOPSIS, while Wind was preferred by Diffuse TOPSIS. In the Andean Region, large-scale hydroelectric and Solar photovoltaic plants obtained high scores in both models. In the Amazon, Biomass led in both models, although with differences in scores. In Orinoquia, Solar Photovoltaic was rated higher by both models. The relevance of this research lies in its ability to address not only Colombia's immediate energy demands, but also in its ability to establish a solid and replicable methodological framework. The application of metaheuristic methods such as TOPSIS and TOPSIS with fuzzy logic is presented as a promising strategy to overcome the limitations of conventional approaches, considering the complexity and uncertainty inherent in the evaluation of renewable energy sources. By achieving a more precise weighting and hierarchization, this study will significantly contribute to strategic decision-making in the implementation of sustainable energy solutions in Colombia, serving as a valuable model for other countries with similar challenges.

Impacts of the High-Pressure Bratsk Hydroelectric Power Station on Fish Population of the Bratsk Reservoir

Environmental and ecological effects of the dam of the high-pressure Bratsk Hydroelectric Power Station (HPS) on the fish population and the probability of fish downstream migration from the Bratsk Reservoir have been studied. It has been revealed that thermal stratification of the water column is a significant factor in the ecological differentiation of the fish population in the upper reaches of high-pressure hydroelectric plants. According to hydroacoustics data, most of the ichthyomass, consisting of “warm-water” representatives of the Percidae (65%) and Cyprinidae (22%) families, is concentrated in the relatively warm layer of the epilimnion. Juvenile fish from 30 to 50 mm in size (up to 70% of the total fish number in this layer) are also concentrated here. In the cold-water hypolimnion, the fish population is represented by large single individuals of whitefish (Coregoninae). The data on distribution of fish in the lower and upper reaches of the dam, fish nutrition patterns, growth rate, and the presence of injuries that occur when fish pass downstream through hydroelectric plant dams are presented. Revealed differences in the growth rate of perches from the upper and lower reaches are associated with their constant inhabiting of water masses with contrasting temperatures. Net catches in the lower reaches over the four seasons of research lack injured individuals. These facts prove the absence of mass downstream passage of fish through the Bratsk HPS dam. Juveniles of cyprinids and perches accumulate in the upper warm layer of 0–10 m, i.e. outside the zone of the intake flow formation, which makes their entrance to intake openings at a depth of more than 20 m hardly possible.

Influence of the Pandeiros Small Hydroelectric Plant reservoir on the concentration and composition of solids transported by the Pandeiros River, Brazil

Influence of the Pandeiros Small Hydroelectric Plant reservoir on the concentration and composition of solids transported by the Pandeiros River, Brazil