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Copyright of Central European Political Studies / Środkowoeuropejskie Studia Polityczne is the property of Faculty of Political Science & Journalism, Adam Mickiewicz University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The emerging floating photovoltaic (FPV) technology is the recent global attention in solar power production due to its high efficiency. Apart from the standalone FPV systems, hybridising the FPV system with the hydroelectric power plants (HEPP) will aid in increasing the power generation from HEPP by reducing the water loss through evaporation. In this study, the power generation and water-saving capacity of a model FPV system with various tilt angles, orientation and tracking mechanisms are analysed by covering 30% of the total area of Vaigai reservoir in India. The study shows that the proposed FPV plant with capacity of 1.14 MW generates 1.9 GWh of energy at its optimum tilt angle while saving 42,731.56 m3 of water annually. Further, cost analysis and carbon footprint estimation are also carried out. The results show that the FPV system will have a positive impact on the environment by saving 44,734.62 tons of CO2.

Hydroelectricity remains the dominate RES (Renewable Energy Source) and the most developed, reaching growth rate peaks in some countries in the 20th century. However, the share of it has fallen over the last few years, as other renewable sources have received rapid development. Despite this, growth for hydroelectricity has remained stable, with China, India, Japan, Russia, Turkey, France, Norway, Canada, USA and Brazil as market leaders. This article analyzes the key trends of development of the hydroelectricity market as a whole, as well as the financial stability of its organizations using bankruptcy likelihood prediction models. The Brazilian and Russian companies were chosen to assess as both countries are classified as developing markets. The bankruptcy prediction models indicate that overall, the financial stability of hydroelectricity giants of Brazil and Russia is at a high level, though profitability ratios are very low. During the COVID-19 pandemic, several financial support measures were implemented by governments, along with the already existing instruments for stimulating renewable energy growth. Authors’ forecasts show that current trends on the market indicate that net addition capacity growth in the next few years will not be enough to meet Net Zero goals for the renewables market.

This work's unique research objective is to assess the possibility of energy harvesting by attaching the piezoelectric patches on the high-density polyethylene floater of aquaculture fish cages. Using Euler-Bernoulli's curved beam theory, the vertical elastic motion of the floater in regular linear sea waves was modeled semi-analytically based on slender body theory and matched asymptotic expansions. Regular linear waves refer to the single frequency waves with small amplitudes compared to the wavelength, for which the linear airy wave theory can approximate the wave characteristics. When the floater elastic motions are determined, the resultant strain is implemented to the governing equation of piezoelectric patches to calculate the generated power. The effect of some variables such as wavenumber, floater bending stiffness, relative floater dimension, and the number of patches in the circumference of the floater on the generated power was investigated. The results indicate that by installing the patches in the proper place, the floater can produce the required electrical power supplying some low-powered electric sensors for monitoring sea environmental conditions or other applications. Also, as a suggestion, installing piezoelectric patches throughout the perimeter of a semi-submerged circular elastic floater is a way of energy harvesting from sea waves. [ABSTRACT FROM AUTHOR]

Through readings of two novels that feature hydroelectric facilities—Peter Abrahams's A Wreath for Udomo and Namwali Serpell's The Old Drift—this article demonstrates how each text grapples in very different ways with the tensions between extractive infrastructures and revolutionary politics. Focusing on a hydroelectric facility yet to be constructed, A Wreath for Udomo reaches for the formal capacities of the novel to stage how the process of formal enclosure specific to and resulting from economic planning results in an analytic enclosure that slowly undoes the possibility of revolutionary anti-capitalism. The Old Drift enacts, I will suggest, an important alternative to the epistemological enclosure foreseen in Abrahams's much earlier novel. Serpell's novel leverages the critical capacity of the historical, genealogical novel to evade the analytical impediments produced by the structure of the hydroelectric dam and the form of economic thinking it both metonymizes and from which such projects result. By constructing parallel revolutionary methods on the levels of characters and readers and content and form, The Old Drift effectively recasts the problem of revolution not in terms of ideological contradiction, as Abrahams does, but as a tension between the constituent components of novelistic and revolutionary totality. [ABSTRACT FROM AUTHOR]

Studies on the development of hydroelectricity in early twentieth century in Spain have paid very little attention to the south-eastern part of the country, specifically the provinces of Alicante and Murcia. The specific needs of this industry (regular flowing rivers and with steep slopes) were in conflict with the fact that there is only one large river in the area, the Segura River, with a scarce flow and major droughts. However, issues related to the use of its waters for irrigation, or periodic flooding or drought, have been prominent themes in research on the Segura River. Despite this, a single company, the Compañía Riegos de Levante S.A. became the most important generator and distributor of electricity in the area until its sale to Hidroeléctrica Española in 1952. Originally, the CRLSA was not established to exploit the new urban electrical consumption markets, but to fulfil the needs of the expanding irrigated agriculture. In this article we will discuss the development of the company, particularly regarding its activities in the electrical energy business and explain the reasons for its establishment and its transformation into a leading company in this industry until the Spanish Civil War. [ABSTRACT FROM AUTHOR]

Previous studies have widely used the aggregate energy consumption in the energy–growth–CO2 emissions nexus, which may not show the relative strength or explanatory power of several energy sources on CO2 emissions. However, less explored in empirical literature are the effects of disaggregated levels of renewable and non-renewable energy sources on environmental quality. This study therefore contributes to fill this important gap for South Africa over the period 1960–2019. Our strategy is distinctively different from previous works in the following dimensions: we employ the recently developed novel dynamic autoregressive distributed lag (ARDL) simulations framework proposed by Jordan and Philips (Stand Genomic Sci 18(4):902–923, 2018) to examine the negative and positive changes in the disaggregated levels of renewable and non-renewable energy sources, trade openness, technique effect, and scale effect on CO2 emissions. Second, we use an innovative measure of trade openness developed by Squalli and Wilson (World Econ 34(10):1745–770, 2011) to capture trade share in GDP as well as the size of trade relative to world trade for South Africa. Third, we use the frequency-domain causality (FDC) approach, the robust testing strategy suggested by Breitung and Candelon (J Econ 132(2):363–378, 2006) which enables us to explore permanent causality for medium-, short-, and long-term relationships among variables under review. Fourth, we employ the second-generation econometric procedures accounting robustly the multiple structural breaks which have been considerably ignored in earlier studies. For South Africa, the key findings are as follows: (i) hydroelectricity and nuclear energy consumptions contribute to lower CO2 emissions in the long run; (ii) the scale effect increases CO2 emissions whereas the technique effect improves it, validating the presence of an environmental Kuznets curve (EKC) hypothesis; and (iii) oil, coal, and natural gas consumptions deteriorate environmental quality. In the light of our empirical evidence, this paper suggests that South Africa's government and policymakers should effectively study the optimal mix of all available energy resources to meet the increasing energy demands while improving the country's environmental quality. [ABSTRACT FROM AUTHOR]

The succession of migration barriers and different turbine types during downstream migration impede Atlantic salmon (Salmo salar L.) smolts from reaching the sea in time but is poorly studied. We investigated the isolated and cumulative impacts of 14 consecutive migration barriers (MBs) on downstream migration of 200 radio‐tagged smolts over an 18.9 km stretch of gravel‐bed river, by equipping five MBs with automated radio listening stations. At the level of isolated barriers, median research times (i.e. time between the first and the last detection upstream of a MB) varied between 0.1 and 0.7 h. The median crossing delays (i.e. time between the first detection upstream and the first detection downstream of a MB) varied between 1 and 2.9 h. Considering successive MBs, median cumulative crossing delays varied between 2.6 and 32.1 h and increased with the number of MBs. We observed a global mortality rate between 33% and 76%, increasing with the distance travelled and the associated number of MBs. Only 48% of the migrating smolts reached the end of the studied river stretch. Results suggest that the dynamics of the smolt downstream migration over this short highly fragmented stretch had a significant effect in terms of delays, mortalities and seaward escapement rate. [ABSTRACT FROM AUTHOR]

Copyright of Caravelle: Cahiers du Monde Hispanique et Luso-Bresilien is the property of Presses Universitaires du Mirail and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Historia 396 is the property of Pontificia Universidad Catolica de Valparaiso, Instituto de Historia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hydroelectric projects are often pursued on the promise of economic development and environmental co-benefits as a source of low-carbon energy. We analyse the case of the Muskrat Falls hydropower mega-project (located in Labrador, Canada) to understand why this project failed to live up to its promised benefits, but instead delivered a double disaster of economic cost and environmental risk. The key concepts of anti-reflexivity and deep stories help us understand why the project assumed an aura of inevitability in political and public discourse until it was too late to change course. Drawing on publicly available data and secondary sources, we identify the constellation of social forces that maintained political anti-reflexivity about the economic and environmental risks of the project and led to a double economic and environmental disaster. Our analysis identifies vital lessons for countering anti-reflexivity and improving environmental governance related to energy mega-projects. [ABSTRACT FROM AUTHOR]

The recent integrated water management policy and carbon-neutral policy can be seen as a turning point that changed the major frameworks of water resource policy and energy policy in the world. Values of hydropower reservoirs, directly related to both policies, should be re-evaluated in terms of resilience. In the past, hydropower reservoirs in Korea have contributed both to flood control and to generating electricity when operating dams within the limited water level during flood seasons. Under such limited operations, the power loss would be inevitable. Therefore, in this study, the concept of resilience was introduced for application to the operation of the hydropower reservoir to minimize such power loss. Also, the framework was able to be used for evaluating power generation performance when setting the target function to the maximization of electricity sale profit. HEC-5 was used for deriving the optimal operation rule, and the scenario was established by referring to the procedure of the general multiple-reservoir operation plan in Korea. As a result of application to the proposed framework, the operation rule that produces the maximum amount of electricity sales was presented, and it was confirmed that flood control and water usage performance could additionally be evaluated. When comparing the past data with optimal operation results for the period 2006~2013, it was found that the resilient operation increased by about 19.83% in terms of electricity generation. In the near future, if various scenarios are added and economic analysis is accompanied, it will be able to judge the best economic effects and the least opportunity costs. [ABSTRACT FROM AUTHOR]

Today, the production of hydroelectricity on the Amazon region is a high stakes endeavor, associated with negative consequences to environment and local communities, be they Amerindian, peasant, traditional or otherwise. Regardless of strong opposition, Brazilian government continues to envision the countries' electricity expansion in this direction. This article questions the long history of the relationship between the Brazilian State and Amazonian rivers, focusing on the Tocantins. Through the different uses and representations around the Tocantins River by various actors, at various scales and over the long term, it aims at understanding how, from a means of access, transport, exchange and communication, this river is transformed into a hydro-electric potential and therefore a resource. By examining the ideas and demands around river development by local elites and the central State, from the colonial era to the Twentieth century, it deals with the evolution of the role of rivers in policies aimed at regional development. In this analysis the role of water as an essential element to understand politics in the Amazon emerges. Furthermore, the article shows the importance of politics at the local scale on the evolution in the relation between claims and priorities in river development policies. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Water Resources / Recursos Hídricos is the property of Associacao Portuguesa dos Recursos Hidricos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Tucuruí hydroelectric dam was built on the Tocantins River in Pará between 1974 and 1984. This article deals with the establishment of the society of the dam through the installation of a company town, to house the various workers involved in this construction. Focusing on the institutional and entrepreneurial point of view, we will deal with the implantation, organization and functioning of this particular space, trying on the one hand to characterize who are the workers who participate in the construction of this dam. And on the other hand, to reflect upon the way in which this type of space controlled by a company participates in the discipline of bodies and workers’ lives inside and outside the construction site, aiming at maximizing productivity. As a space of control, there are inevitably reactions that will also be part of this analysis. This research follows the course of the institutional and technical sources of the construction of dams to try to characterize the implementation and management of a construction site during the military dictatorship

Harvesting energy from the environment offers many opportunities for the generation of clean power from self‐sustained systems and provides great promise for ameliorating the growing threat of the global environmental issues and the energy crisis. Ambient moisture and natural water sources have attracted huge research interest in the field of energy harvesting and conversion due to easy access, good sustainability, and the ubiquity of water on Earth. Taking advantage of the active interaction between water molecules and solid interfaces, various functional materials have been demonstrated to harvest energy and generate useable amounts of electrical power from water. In this review, some perspective on the development of water‐enabled electricity generation is given. The current preferred methods for water‐enabled electricity generation and relevant functional materials are summarized. Also, how the development of new materials and systems has led to significant improvements in the electrical power output reported for these devices is discussed. Then, some recent advances that have resulted in dramatic increases in the electrical output available from water‐enabled electrical generators (WEEGs) is discussed. Finally, some future trends in the development of WEEGs are outlined, and how this may result in practical applications and commercialization of these devices is shown.

Millions of off-grid homes in remote areas around the world have access to pico-hydro (5kW or less) resources that are undeveloped due to prohibitive installed costs ($/kW). The Turgo turbine, a hydroelectric impulse turbine generally suited for medium to high head applications, has gained renewed attention in research due to its potential applicability to such sites. Nevertheless, published literature about the Turgo turbine is limited and indicates that current theory and experimental knowledge do not adequately explain the effects of certain design parameters, such as nozzle diameter, jet inlet angle, number of blades, and blade speed on the turbine's efficiency. In this study, these parameters are used in a three-level (34) central composite response surface experiment. A low-cost Turgo turbine is built and tested from readily available materials and a second order regression model is developed to predict its efficiency as a function of each parameter above and their interactions. The effects of blade orientation angle and jet impact location on efficiency are also investigated and experimentally found to be of relatively little significance to the turbine. The purpose of this study is to establish empirical design guidelines that enable small hydroelectric manufacturers and individuals to design low-cost efficient Turgo Turbines that can be optimized to a specific pico-hydro site. The results are also expressed in dimensionless parameters to allow for potential scaling to larger systems and manufacturers.

Copyright of Scienze del Territorio is the property of Firenze University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Energy and environmental diplomacy factors were a major, though often unrecognized, part of Canada-United States relations prior to the Cold War. Hydroelectricity was the most important of these factors, particularly power exported from the Canadian side of the Great Lakes-St. Lawrence basin. The history of Canada-U.S. hydroelectricity relations, exports, and regulations offered here covers the key steps, institutions, and actors in the evolution of hydroelectricity geopolitics and governance regimes during the first two-thirds of the twentieth century. Most of the earliest large Canadian hydropower projects were built on or planned for border waters, which, after the creation of the 1909 Boundary Waters Treaty, required formal coordination with the United States. Over the following half-century, prospective power projects on border waters continued to dominate the diplomatic dialogue. Federal governments or agencies established broad export restrictions, altering them occasionally, but often subnational governments, special interests, and specific power projects played as large a role in shaping the power trade. The result was a constantly shifting political and regulatory context, albeit one that generally trended toward cooperation and reduced barriers to electricity integration. [ABSTRACT FROM AUTHOR]

We synthesize the interconnected impacts of Texas' water and energy resources and infrastructure including the cascading effects due to Winter Storm Uri. The government's preparedness, communication, policies, and response as well as storm impacts on vulnerable communities are evaluated using available information and data. Where knowledge gaps exist, we propose potential research to elucidate health, environmental, policy, and economic impacts of the extreme weather event. We expect that recommendations made here — while specific to the situation and outcomes of Winter Storm Uri — will increase Texas' resilience to other extreme weather events not discussed in this paper. We found that out of 14 million residents who were on boil water notices, those who were served by very small water systems went, on average, a minimum of three days longer without potable water. Available county-level data do not indicate vulnerable communities went longer periods of time without power or water during the event. More resolved data are required to understand who was most heavily impacted at the community or neighborhood level. Gaps in government communication, response, and policy are discussed, including issues with identifying — and securing power to — critical infrastructure and the fact that the state's Emergency Alert System was not used consistently to update Texans during the crisis. Finally, research recommendations are made to bolster weaknesses discovered during and after the storm including (1) reliable communication strategies, (2) reducing disproportionate impacts to vulnerable communities, (3) human health impacts, (4) increasing water infrastructure resilience, and (5) how climate change could impact infrastructure resilience into the future. [ABSTRACT FROM AUTHOR]

This paper focuses on territorial recomposition in Canadian rural areas generated by the evolution of power balances among local actors, civil society and public authorities, and exogenous powers. In a postcolonial context, the economic development model of Canadian peripheral areas remains strongly influenced by the power of extractivist companies, intensively exploiting natural resources for export. Such extractivist business is detrimental to local communities and their life environment built into complex socio-natural relationships. What we want to show is that local (counter)powers, emerging during social mobilizations against extractivism, may generate alternative development trajectories, respectful with territorial environments and their socio-natural relationships. The case study we develop is about the region of Lac-Saint-Jean in Quebec Province and hydroelectric resource. We will focus on two projects, one generated by a community resistance against large hydroelectric dams, the other by an inter-ethnic public partnership for the development of mini-power plants.

Le processus de création du Parc national Tursujuq (Nunavik) a été initié par le gouvernement québécois en 1992, mais les populations locales eeyouch et inuit n’ont participé directement qu’à partir de 2006. À cette époque, un plan d’aménagement relativement élaboré était déjà déterminé pour le secteur ; l’étude des consultations publiques révèle un sentiment d’impuissance face à ces projets approuvés d’avance par les ministères, malgré la constitution d’un comité local d’harmonisation impliquant des membres de la communauté. C’est du moins ce que laisse croire le cas de la rivière Nastapoka, réservée pour un développement hydroélectrique dès 2002, et apparemment indiscutablement exclue des limites du parc malgré les demandes unanimes de la population pour la protéger. Cet article vise dans un premier temps à mieux comprendre le sentiment d’impuissance vécu par les populations locales, dû à l’inefficacité du processus démocratique de consultation citoyenne de même qu’à la position coloniale du gouvernement québécois par rapport aux peuples autochtones, une position renforcée par le rôle symbolique de l’hydroélectricité dans la définition de l’identité nationale. Dans un second temps, une analyse des discours liés à la rivière Nastapoka permettra de comprendre comment la mise en récit du paysage peuvent permettre aux populations autochtones de (re)prendre le contrôle de l’histoire et de la signification symbolique de celui-ci, donc d’en influencer l’aménagement.

Energy consumption in Pakistan has increased considerably over the last two decades particularly due to industrialization, urbanization, and population growth. To keep pace with the economic growth, the growing energy demands have been fulfilled at the cost of switching from abundant, cheap, and environmentally friendly domestic hydropower to expensive, imported, and higher GHG emitting petroleum products, thus leaving Pakistan at the mercy of global oil crises and environmental degradations. While employing the trans -log production framework, this study has investigated the potential inter-fuel and inter-factor substitution among energy vs. non-energy factors in calculating substitution elasticities between pairs of labour, capital, petroleum, coal, natural gas, and hydroelectricity in order to design policy for Pakistan on how to ensure secure energy and environmental protection. Using the time-series data covering the period 1980–2017, the ridge regression technique was adopted to calculate parameter estimates. The findings show that labour-energy and capital-energy are substitutes, thus signifying the need for greater focus on technological progress and skilled employment creation to save energy and mitigate CO 2 emissions. The gradual removal of energy subsidies is suggested to discourage inefficient energy use and stimulate capital-intensive production approaches. The findings also advocate the significance of a diversified energy-mix consisted of hydroelectricity and natural gas. [ABSTRACT FROM AUTHOR]

Focusing on the planning and construction of the Sanmenxia hydropower project, this article analyses the dynamics and tensions between energy demand and the nature of the Yellow River in the twentieth century. From the late 1920s, Japanese engineers aimed to develop hydroelectric power by building dams on the Yellow River. They viewed the Yellow River as an important source of hydroelectric power for building the Greater East Asian Co-Prosperity Sphere. When Chinese Communists took control, they claimed that the primary function of the Sanmenxia project was flood control. Yet, influenced by the Soviet Union and the Chinese Communist state's industrialisation efforts, the engineers also emphasised the generation of electrical power, which resulted in a high dam design. The silting of the reservoir, however, frustrated the ambition of the Chinese leaders and engineers and resulted in the production of much lower and unstable power output upon the dam's completion. [ABSTRACT FROM AUTHOR]

The emerging floating photovoltaic (FPV) technology is the recent global attention in solar power production due to its high efficiency. Apart from the standalone FPV systems, hybridising the FPV system with the hydroelectric power plants (HEPP) will aid in increasing the power generation from HEPP by reducing the water loss through evaporation. In this study, the power generation and water-saving capacity of a model FPV system with various tilt angles, orientation and tracking mechanisms are analysed by covering 30% of the total area of Vaigai reservoir in India. The study shows that the proposed FPV plant with capacity of 1.14 MW generates 1.9 GWh of energy at its optimum tilt angle while saving 42,731.56 m3 of water annually. Further, cost analysis and carbon footprint estimation are also carried out. The results show that the FPV system will have a positive impact on the environment by saving 44,734.62 tons of CO2. [ABSTRACT FROM AUTHOR]

Water footprint indicator describes direct and indirect use of waters for humanity. Three different methods are used to calculate the water footprint of electricity generation in a hydroelectric power station or the water footprint of processes associated with the operation of reservoirs. This article analyses a method referred to as “net consumption”, which assumes that, even before reservoir construction, there was evaporation from the area of a future reservoir. According to this method, water loss from the hydroelectric power station system is the difference between evaporation from the water reservoir surface and evaporation from the earth's surface before reservoir construction.The article presents several arguments as to why this method is wrong and should not be used as part of the methodology for calculating the water footprint of hydropower. The main arguments are: 1) the “net consumption” method does not describe the value of the water footprint of the product (i.e., consumption per unit of electricity), but the change in the water balance of the territory; 2) the “net consumption” method is not compatible with the methods of calculating the water footprint of similar products and water footprint methodology in general; 3) the “net consumption” method may lead to inappropriate conclusions about the sustainability of the construction and operation of a reservoir. The individual arguments are documented with examples.

Mountain huts, as special, stand-alone, micro-grid systems, are not connected to a power grid and represent a burden on the environment. The micro-grid has to be flexible to cover daily and seasonal fluctuations. Heat and electricity are usually generated with fossil fuels due to the simple on-off operation. By introducing renewable energy sources (RESs), the generation of energy could be more sustainable, but the generation and consumption must be balanced. The paper describes the integration of a hydrogen-storage system (HSS) and a battery-storage system (BattS) in a mountain hut. The HSS involves a proton-exchange-membrane water electrolyser (PEMWE), a hydrogen storage tank (H 2 tank), a PEM fuel cell (PEMFC) and a BattS consisting of lead-acid batteries. Eight micro-grid configurations were modelled using HOMER and evaluated from the technical, environmental and economic points of view. A life-cycle assessment analysis was made from the cradle to the gate. The micro-grid configurations with the HSS achieve, on average, a more than 70% decrease in the environmental impacts in comparison to the state of play at the beginning, but require a larger investment. Comparing the HSS with the BattS as a seasonal energy storage, the hydrogen-based technology had advantages for all of the assessed criteria. • Eight configurations of mountain-hut stand-alone energy system are studied. • A novel approach using technical, economic and environmental criteria is introduced. • Hydrogen-storage combined with renewable energy sources is the optimal solution. • For seasonal energy storage, hydrogen is more favourable than a battery-storage. [ABSTRACT FROM AUTHOR]

The exploitation of RES and their combination with desalination may be the solution to water scarcity and volatility of the electricity grids in remote offshore areas around the world. This research work investigates an HRES of a 12 MW wind park, a 1.8 MW photovoltaic park and a 1000 m3/d desalination plant in Karpathos, Greece. Concerning the wind and solar power, 30% and 20% respectively is integrated to the grid and the remaining is obtainable for desalination and water pumping, which is used as energy storage. The surplus energy returns to the grid, reducing the deficit. The project's lifespan is 40 years, rendering the stochastic time series necessary and the paper culminates in the economic sustainability investigation of this HRES. Several results can be obtained, as follows: i) the HRES′ reliability is high, since the system is able to cover the entire drinking water needs of the island, 89.75% of irrigation and 50.63% of energy needs. ii) The wind and solar potential of Karpathos has a decisive role, possessing the 3.02% of the total produced energy. iii) The IRR of various selling prices of desalinated water and energy ranges from 10% to 17%, rendering the investment viable and even profitable. • The HRES meets the island's entire drinking water needs, 90% irrigation and 51% of its energy needs. • The PSH produces 36% of the energy, increasing the HRES′ efficiency by exploiting the energy excess. • The ARMA (1,1) stochastic model is implied to include the uncertainty of rainfall and temperature. • The Negra et al. method is implied to simulate the variability of wind speed, for the project's lifespan. • The cost-benefit analysis shows that the HRES is viable economically, with IRR ranging from 10 to 17%. [ABSTRACT FROM AUTHOR]

The objective of this study is to estimate the impact of climate change on the hydroelectric potential of various basins across South America. Three different downscaled global climate models are used to estimate the percentage changes in rainfall and streamflow by the 2030s and 2080s under a high emission scenario in comparison to 1961–1990 baseline data. While rainfall is projected to increase slightly over the Uruguay River basin, rainfall over the Amazon and Brazil's Northeast region is expected to decline. As a consequence of climate change, streamflow in the São Francisco River, Tocantins River and Parnaiba River is projected to decline 46%, 31% and 26%, respectively in the coming 3 decades compared to data from 1961 to 1990. Furthermore, the increasing demands for water from the São Francisco River could become greater than available streamflow by the 2030s. Additionally, one of the three climate models indicated that the São Francisco and Parnaiba Rivers' streamflow and hydroelectric production could potentially cease in the second half of the 21st century. Despite some inconsistencies between the long term projections from the 3 different climate models, the results of this research are important in the context of regional climate change, agricultural and energy resource planning. • Rainfall over tropical and semiarid South America is projected to decline due to climate change. • Streamflow and runoff are projected to decline in the coming decades in 9 of the 10 river basins studied. • This could result in markedly reduced hydroelectric potential and water scarcity by 2070. • Growing water demands from the São Francisco River could exceed available supply by 2035. [ABSTRACT FROM AUTHOR]

Taking the St. Lawrence River watershed as a study area, this paper examines grassroots protests that emerged during the 1970s in Québec, New York State, and Ontario. At issue in all three cases was a reaction to large-scale energy projects that many local people believed threatened human health and economic well-being. The essay draws upon what Barry Weisberg termed the "politics of ecology" (1970), in analyzing the strategies and outcomes evident in the three cases. This paper argues that rural people in the watershed employed new and innovative human-nature paradigms as they opposed large public utilities. Across the international boundary, the groups supported one another's campaigns by sharing information and expertise in their common quest to protect their shared environment. [ABSTRACT FROM AUTHOR]

ABSTRACTRenewable Energy Sources (RES) are well – defined as energy sources, that are in abundance within the natural surroundings and are much inexhaustible. In addition, hydroelectricity (HE) is a vital part of world renewable energy supply and hydropower remains a bulk source of electricity generation because of its environmental friendliness in nature. Modeling is the analysis of the non-linear models which represents the fundamental parts of the hydropower plant (governor, turbine, servomotor). This paper studies accurate and elaborate hydraulic turbine and governor models and its implementation in MATLAB/Simulink combined with the Simscape Power Systems (SPS). An effort has been created to develop a plant model and examine the suitableness of controllers during a governor model for fault incidence within the system by means Simulink based simulation. The Ziegler– Nichols tuning methodology was applied for specifying the gain coefficients of the governor (PID-PI) under 50% of load demand from the plant. Also, MATLAB/Simulink gave the chance to record and compare the figures of the plant with PID & PI controllers through simulation tests within the commonest cases (three-phase fault, load demand variation) with a view of finding out the potency and therefore the stability of the system.

Abstract Background Fragmentation (establishment of barriers e.g., hydropower dams, reservoirs for irrigation) is considered one of the greatest threats to conservation of river systems worldwide. In this paper we determine the fragmentation status of central Chilean river networks using two indices, namely Fragmentation Index (FI) and Longest Fragment (LF). These are based on the number of barriers and their placement as well as river length available for fish movement. FI and LF were applied to eight Andean river basins of central Chile in order to assess their natural, current (2018) and future (2050) fragmentation at the doorstep of a hydropower boom. Subsequently, we exemplify the use of these indices to evaluate different placement scenarios of new hydropower dams in order to maximize hydropower use and at the same time minimize impact on fish communities. Results In the natural scenario 4 barriers (waterfalls) were present. To these 4 barriers, 80 new ones of anthropogenic origin were added in the current (2018) scenario, whereas 377 new barriers are expected in near future (2050). Therefore, compared to the ‘natural’ scenario, in 2050 we expect 115-fold increase in fragmentation in analysed river systems, which is clearly reflected by the increase of the FI values in time. At the same time, the LF diminished by 12% on average in the future scenario. The fastest increase of fragmentation will occur in small and medium rivers that correspond to 1st, 2nd and 3rd Strahler orders. Finally, case study on configuration of potential hydropower plants in the Biobío basin showed that hydropower output would be maximized and negative effects on fish communities minimised if new hydropower plants would be located in tributaries of the upper basin. Conclusions Fragmentation of Chilean Andean river systems is expected to severely increase in near future, affecting their connectivity and ecological function as well as resilience to other anthropogenic stressors. Indices proposed here allowed quantification of this fragmentation and evaluation of different planning scenarios. Our results suggest that in order to minimise their environmental impact, new barriers should be placed in tributaries in the upper basin and river reaches above existing barriers.

Hydroelectric projects are often pursued on the promise of economic development and environmental co-benefits as a source of low-carbon energy. We analyse the case of the Muskrat Falls hydropower mega-project (located in Labrador, Canada) to understand why this project failed to live up to its promised benefits, but instead delivered a double disaster of economic cost and environmental risk. The key concepts of anti-reflexivity and deep stories help us understand why the project assumed an aura of inevitability in political and public discourse until it was too late to change course. Drawing on publicly available data and secondary sources, we identify the constellation of social forces that maintained political anti-reflexivity about the economic and environmental risks of the project and led to a double economic and environmental disaster. Our analysis identifies vital lessons for countering anti-reflexivity and improving environmental governance related to energy mega-projects.

Hydroelectric facilities often release water at variable rates over the day to match electricity demand, resulting in short-term variability in downstream discharge and water levels. This sub-daily variability, known as hydropeaking, has mostly been studied at large facilities. The ongoing global proliferation of small hydropower (SHP) facilities, which in Brazil are defined as having installed capacities between 5 and 30 MW, raises the question of how these facilities may alter downstream flow regimes by hydropeaking. This study examines the individual and cumulative effects of hydropower facilities on tributaries in the upland watershed of the Pantanal, a vast floodplain wetland system located on the upper Paraguay River, mostly in Brazil. Simultaneous hourly discharge measurements from publicly available reference and downstream gage stations were analyzed for 11 reaches containing 24 hydropower facilities. Most of the facilities are SHPs and half are run-of-river designs, often with diversion channels (headraces). Comparison of daily data over an annual period, summarized by indicators of hydrological alteration (HA) that describe the magnitude, frequency, rate of change, and duration of flows, revealed differences at sub-daily scales attributable to hydropeaking by the hydropower facilities. Results showed statistically significant sub-daily HA in all 11 reaches containing hydropower facilities in all months. Discharge indicators that showed the highest percentage of days with increased variability were the mean rates of rise and fall, amplitude, duration of high pulses, maximum discharge, and number of reversals. Those that showed higher percentages of decreased variability included minimum discharge, number of high pulses, duration of stability, and number of low pulses. There was no correlation between HA values and physical characteristics of rivers or hydropower facilities (including installed capacity), and reaches with multiple facilities did not differ in HA from those with single facilities. This study demonstrates that SHPs as well as larger hydropower facilities cause hydrological alterations attributable to hydropeaking. Considering the rapid expansion of SHPs in tropical river systems, there is an urgent need to understand whether the ecological impacts of hydropeaking documented in temperate biomes also apply to these systems.

Small hydroelectric power (SHP) facilities are proliferating around the world, including in Brazil where legislation encourages SHP over other hydropower development, defining SHP as facilities with installed capacities of 3–30 MW and reservoirs <13 km2. SHP facilities are often diversion designs with small or no reservoirs, while other SHPs have more conventional dams that create extensive reservoirs. This study seeks to understand the relative impacts of these two different designs on downstream water quality, comparing a conventional SHP system on the main stem to a complex of smaller SHPs with diversion designs in lower‐order reaches of the São Lourenço River. This river delivers nutrients and sediments to the Pantanal, one of the world's largest floodplain ecosystems. Samples collected upstream and downstream of each set of facilities over a range of flows revealed that the conventional SHP reservoir significantly reduced pH, dissolved oxygen, total iron, suspended solids, and turbidity consistent with observations in many other reservoirs. In contrast, water quality changes downstream of the smaller SHPs were less pronounced and could be attributable to natural variability. An analysis of energy production versus water quality impacts suggests that SHPs on the smaller tributaries are favorable compared to the conventional SHP in terms of water quality impacts. With the proposed addition of dozens of new facilities in the upland watersheds draining into the Pantanal, this study improves our understanding of the relative impacts of different designs of SHPs on downstream water quality, while recognizing that water quality is just one of several potential impacts to be considered. [ABSTRACT FROM AUTHOR]