Search

This study is an attempt to determine whether the need to get hydropower project appraisals perfectly right during the pre-construction phase, so as to prevent significant overruns along with benefit shortfalls, should supersede the need to deliver projects at the earliest possible time so as to meet the needs of the people. To achieve the study objective, we test whether the Hiding Hand principle is predominantly benevolent or malevolent. We argue that if the Hiding Hand is benevolent, then project stakeholders are better off focusing on the quick delivery of power projects; however, if it is malevolent, then more attention should be given to perfecting project appraisals. It transpires from the statistical analysis that the Benevolent Hiding Hand dominates the Malevolent Hiding Hand in the selected World Bank-financed hydropower projects (33% v. 21%), and that ultimately, 75% of the projects were even more successful than anticipated—while 25% of the projects failed. Our findings further show that while a total loss of 2.335 billion USD in the sampled dams was caused by the Malevolent Hiding Hand, 11.259 billion USD was gained as a result of the Benevolent Hiding Hand. The predominance of the Benevolent Hiding Hand justifies placing some weight on proceeding with hydropower projects that show significant promise even if all the implantation risks are not fully quantified at the appraisal stage, especially in developing countries.

The use of these new interaction tool implies the improvement of the awareness of the whole system and it lies in improving the sustainability and efficiency of the water systems with the integration of measurements. The research proposed a methodology, which enables improvement in the accuracy and reliability of data and it increases the performance of water systems. This study proposes a pressure-reduction strategy and the implementation of pumps as turbines (PATs), applicable in Sta Cruz, Madeira water system. The use of the developed digital twin model assures a decrease of 3.3 hm3 in water-demand volume, increasing renewable generation by micro-hydropower up to 1.2 GWh. These actions would result in savings above 1.5 M€, decreasing around 530 tons of CO2 emissions each year. The consideration of these values implies the improvement of different indicators, which allows the evaluation of different targets linked to sustainable development goals (SDGs). A digital twin is a tool, which enables a real-time simulation of the water systems and therefore, the water managers can make a decision in the management of the water system over time. The use of these new interaction tool implies the improvement of the awareness of the whole system and it lies in improving the sustainability and efficiency of the water systems with the integration of measurements. The research proposed a methodology to integrate GIS and water models, being the main goal the integration of social, economic, environmental and technical issues. This integration enables improvement in the accuracy and reliability of data and it increases the performance of water systems. This study proposes a pressure-reduction strategy and the implementation of pumps as turbines (PATs), applicable in Sta Cruz, Madeira water system. The use of the developed digital twin model assures a decrease of 3.3 hm3 in water-demand volume, increasing renewable generation by micro-hydropower up to 1.2 GWh. These actions would result in savings above 1.5 M€, decreasing around 530 tons of CO2 emissions each year. The consideration of these values implies the improvement of different indicators, which allows the evaluation of different targets linked to sustainable development goals (SDGs). © 2023 Informa UK Limited, trading as Taylor & Francis Group.

Hydraulic fracturing is one of the most common methods to determine in-situ rock stress. The interpretation of the shut-in pressure to determine the minor principal stress is an important element of this method, and many different methods to interpret shut-in pressure have been studied and developed throughout the years. Each method has its advantages and disadvantages. With more than 50 years of research and development within the rock stress measurement field, especially in HF, SINTEF has established two practical ways of defining shut-in pressure. These methods are independent and termed zero flow and water hammer. The zero flow method has been used by SINTEF in more than 130 projects over the last 30 years. The methods clearly differ from the other methods as they are based on singular events in the development of pressure/flow versus time which enables us to read the shut-in pressure directly during testing. In this paper a comparison is made between different methods for interpretation of shut-in pressure, including 12 existing methods and the two SINTEF methods. Comprehensive laboratory tests were performed, and a field test was selected from SINTEF's database for demonstration and comparison of the methods. The SINTEF methods have been developed mainly for use in hard rock environment where the rock is a jointed aquifer and with low permeability. The application of the two methods have traditionally been hydroelectric power development, different types of tunnel and cavern projects, and also in mineral mining. The methods have not been used in deep petroleum applications such as oil wells or offshore in porous rock types. Highlights of the article: • There are 12 established methods for shut-in pressure estimation in hydraulic fracturing. All methods have certain advantages and disadvantages. • SINTEF has developed two methods namely zero flow and water hammer. • The SINTEF methods are documented through laboratory and in-situ tests. • A comparison of the two SINTEF methods with the existing methods has been done. Two New Methods for Defining Shut-In Pressure in Hydraulic Fracturing Tests Hydraulic fracturing is one of the most common methods to determine in situ rock stress. The interpretation of the shut-in pressure to determine the minor principal stress is an important element of this method, and many different methods to interpret shut-in pressure have been studied and developed throughout the years. Each method has its advantages and disadvantages. With more than 50 years of research and development within the rock stress measurement field, especially in HF, SINTEF has established two practical ways of defining shut-in pressure. These methods are independent and termed zero flow and water hammer. The zero flow method has been used by SINTEF in more than 130 projects over the last 30 years. The methods clearly differ from the other methods as they are based on singular events in the development of pressure/flow versus time which enables us to read the shut-in pressure directly during testing. In this paper, a comparison is made between different methods for interpretation of shut-in pressure, including 12 existing methods and the 2 SINTEF methods. Comprehensive laboratory tests were performed, and a field test was selected from SINTEF’s database for demonstration and comparison of the methods. The SINTEF methods have been developed mainly for use in hard rock environment where the rock is a jointed aquifer and with low permeability. The application of the two methods has traditionally been hydroelectric power development, different types of tunnel, and cavern projects, and also in mineral mining. The methods have not been used in deep petroleum applications such as oil wells or offshore in porous rock types.

At operational level, fossil fuel phase-out and high shares of non-dispatchable renewable energy resources (RES) will challenge the system operator's (SO) ability to balance generation, and the demand at any time. The variability of RES output ranges from one hour to a season, and critical events such as low supply and high demand might occur more frequently and for more extended periods. When evaluating the role of Energy Storage Systems (ESSs) in this context, the need for a long time scope to capture the different RES variabilities must be reconciled with the need for modeling the hourly chronology. This paper presents a medium-term operation planning model, addressing both the energy dispatch and the balancing services. This study shows that representing the combined chronological variability of demand and RES production is essential to properly assess the roles of different kinds of ESSs in the future 2030 electricity mix. Otherwise, it would not be possible to appropriately capture the frequency, depth, and length of events for which ESSs are activated. The analysis also highlights the importance of considering balancing services, given the significant contribution of batteries to the reserve market. Finally, the results show that batteries and Pumped Storage Hydro (PSH) have different roles in the Spanish electricity system with a high renewable penetration. While PSH is mainly used to provide energy during critical periods, batteries mostly provide balancing services. © 2022 The Author(s) This research has been carried out thanks to the Spanish Ministry of Economy and Competitiveness MINECO through BC3 Mar?a de Maeztu excellence accreditation MDM-2017-0714 Maria de Maeztu Grant. The research has also benefited from the funding of the RETOS COLABORACI?N program of the Spanish Ministry of Science and Innovation and the Spanish State Research Agency (project ?Platform of innovative models to accelerate the energy decarbonization of the economy (MODESC)?, with reference number RTC2019- 007315-3). The authors would also like to acknowledge the Iberdrola Chair of Energy and Innovation for their helpful comments.

The Columbia River Treaty (CRT) signed between the United States and Canada in 1961 is known as one of the most successful transboundary water treaties. Under continued cooperation, both countries equitably share collective responsibilities of reservoir operations and flood control and hydropower benefits from treaty dams. As the balance of benefits is the key factor of cooperation, future cooperation could be challenged by external social and environmental factors which were not originally anticipated or change in the social preferences of the two actors. To understand the robustness of cooperation dynamics, we address two research questions. (i) How does social and environmental change influence cooperation dynamics? (ii) How do social preferences influence the probability of cooperation for both actors? We analyzed infrastructural, hydrological, economic, social, and environmental data to inform the development of a socio-hydrological system dynamics model. The model simulates the dynamics of flood control and hydropower benefit sharing as a function of the probability to cooperate, which in turn is affected by the share of benefits. The model is used to evaluate scenarios that represent environmental and institutional change and changes in political characteristics based on social preferences. Our findings show that stronger institutional capacity ensures equitable sharing of benefits over the long term. Under the current CRT, the utility of cooperation is always higher for Canada than non-cooperation, which is in contrast to the United States. The probability to cooperate for each country is lowest when they are self-interested but fluctuates in other social preference scenarios.

The Zuppinger water wheel, developed in the 1850s, is one of the most efficient water wheels and is commonly used for low-head hydropower generation. The high efficiencies of the wheel over a wide operating range, its simplicity in design and slow rotational speed offer a low-cost and environmentally friendly low-head hydropower solution. A physical and numerical model study of a wheel is presented in this paper. Three-dimensional numerical simulations were performed using the computational fluid dynamics (CFD) code Flow-3D. The influence of grid size on the results of the numerical model was assessed using a systematic grid refinement study. Grid convergence indices (GCIs) were calculated for two grid sets each, with three different grid sizes, using a constant grid refinement ratio. The GCIs were reduced to levels below 5% for the selected quantities of interest. The CFD model results were compared with physical model results at different operating points of the wheel. The maximum differences in power output and efficiency between the physical and numerical model results were 2.5% and 8%, respectively.

Freshwater habitats and species have been lost because of river constructions, particularly regarding hydropower plants. Such losses may be mitigated, for example, by providing compensatory habi tats. We present a case which had the objective to promote reproduction of a key species. Imatra City Brook in Finland was constructed in 2014 at a hydropower dam as a new reproduction area for brown trout (Salmo trutta L.). In the planning phase, the objective was to maximize suitable habitat types and areas with limited discharge. Monitoring shows promising densities of brown trout juve niles within only three years, inspiring hope for high smolt production in the main river. The increase in total macroinvertebrate abundances and taxa numbers in the second year of monitoring showed that species richness was comparable to that in natural rivers, and the brook was in a good eco logical state. This case confirms the expected high potential of spawning and rearing channels to improve migratory fish stocks and compensate for lost habitats in constructed rivers.

The stability of the surrounding rocks of large underground powerhouses is always emphasized during the construction process, especially in large-scale underground projects under construction, such as the Baihetan hydropower station in China. According to field investigations, numerical simulations and monitoring data analysis, we present a comparative analysis of the deformation and failure characteristics of the surrounding rocks of underground powerhouses on the left and right banks of the Baihetan hydropower station. The failure characteristics and deformation magnitude of the underground powerhouses on the left and right banks are quite different. Under the disadvantageous condition where the maximum principal stress intersects the axis of the powerhouse at a large angle, the left bank underground powerhouse shows prominent stress-controlled failure characteristics such as spalling, slack collapse and concrete cracking. Although the maximum principal stress is in the favorable condition which intersects the right bank powerhouse at a small angle, the relatively high intermediate principal stress with an angle subvertical to the right bank powerhouse plays an essential role in its deformation and failure, indicating that the influence of high intermediate principal stress cannot be ignored. In addition, structural plane-controlled failure and large deformation are also more evident on the right bank due to the extensive distribution of weak structural planes and complex surrounding rock properties.

This article argues for conceptualising the land-water nexus not primarily in spatial terms, but above all as a set of spatiotemporal rhythms of increasing and decreasing wetness and fluidity. By investigating human engagement with water and land as rhythms, the corresponding and conflicting dynamics of particular places becoming – for longer or shorter periods – land, water or a mixture of both can be traced as an evolving web of relationships between human imaginations and practices, and the materialities of water, mud, sediment, dams, floodgates, etc. The article illustrates this approach with two brief ethnographic examples from northern Europe: In the depopulated Estonian Soomaa wetlands, some of the few remaining inhabitants are in the process of redefining unruly fluctuating water as a tourism destination. In doing so, however, these tourism operators are finding themselves and their “products” caught up in volatile and complicated spatiotemporal dynamics, including the difficulty to predict flooding and to coordinate high water with their potential customers’ spare time, which is bound to working/school weeks and public holidays. On the Kemi River in Finnish Lapland, water flows are not only conditioned by precipitation and seasons, but also – through an intricate hydropower infrastructure – by the electricity market, triggering continued disputes about appropriate spatiotemporal rhythms in the land-water nexus. Seasonality and hydroelectricity generation point to the inherent rhythmicity of the land-water nexus, which is significant not only because it reflects the experience of people inhabiting and engaging with their in-between environments. A rhythms approach can also de-centre the (often illusive) quest for what the water-land nexus is, and instead focus on how this nexus continually comes into being and is negotiated by both its inhabitants and other people. This argument builds on anthropological thinking about temporality and materiality, and indicates how the two must be combined for better understanding how human life relates to the land-water nexus.

Due to the inherent uncertainty and intermittence of wind power, and the geographical mismatch between the wind power bases and the load demand, the problem of wind curtailment is becoming increasingly serious in China. To promote the consumption of wind power, this paper studies the short-term operation of a wind farm-pumped storage hydropower plant (WF-PSHP) hybrid system which transmits power to multiple cross-regional power grids through ultra-high-voltage (UHV) transmission lines. In this study, the forecasted error distribution of wind power is fitted using kernel density estimation. An optimization model that considers the peak shaving demands of receiving-end power grids (REPGs) is then established to determine the daily operation of the WF-PSHP system. The hydraulic constraints of the PSHP and individual unit operation constraints are also taken into account to make the model more accurate. To improve the solving efficiency, the original stochastic model is transformed into a deterministic mixed-integer linear programming (MILP) problem through several deterministic conversion and linearization techniques. The real-world case studies demonstrate that the integrated transmission of the WF and PSHP can reduce the peak-valley difference of the REPGs while absorbing large-scale wind power on different typical days in summer and winter.

Human activities are directly related to fossil fuel consumption and cause global warming and climate change effects by emitting greenhouse gas into the lower atmosphere. To reduce and adapt to such effects, renewable energy sources such as surface dams, including hydroelectric energy (HE) generation units, are gaining importance. In the current literature, HE potential calculations are based on formulations that are quite simple, clear and do not distinguish between different situations. In this paper, two classification methodologies are proposed for better assessment of HE production. The first one is based on the concept of the hypsographic curve to distinguish different drainage basin features into "Young," "Mature" and "Old." The second classification takes into account the newly defined energy index (EI) principle, which helps to classify the HE generation capability of drainage basins into "Very low," "Low," "Normal," "High" and "Very high." The application of the proposed methodology is presented for three drainage basins from the upstream sub-basins of the Tigris River in Turkey. A comparison of the results shows that the proposed methodologies not only give numerical values but also sets linguistically rational and logical rules for the HE potential of a drainage basin. In the upstream basin of the Tigris River, the EI values vary between 0.705 and 0.122, corresponding to the "High" and "Low" categories, respectively. It is recommended that these two classification procedures be considered before the construction of any dam for HE production.

Excavation is common in the construction of hydropower projects. Monitoring for both stable and unstable slopes is a pressing requirement during progressive excavations with or without cut-slope support measures. The present study is about an excavation carried out in a proposed concrete gravity dam site on the right bank slope of the Punatsangchhu River in western Bhutan. During the excavation, the right bank abutment witnessed multiple events of slope failures of various magnitudes. One major landslide occurred on 23 July 2013 in the toe of the right abutment, where foliation/multiple sheared/fractured zones/seams in quartz-feldspathic biotite gneiss dip towards the valley. During further excavations/piling works, a subsequent landslide on the downstream, within the body of the July 2013 landslide, occurred on 12 August 2016. As a result, a real-time monitoring of the slope became necessary to facilitate further excavations for achieving the dam foundation. Thus, the advanced slope monitoring instrument like Image By Interferometric Survey – Frequency Modulated (IBIS-FM) radar was deployed for monitoring the right bank slope during the excavation for the construction of ∼129 m high dam. The displacement of the hill slope is assessed based on this system by monitoring point locations as well as areas by assigning different threshold values for providing timely alerts. This real-time monitoring was effective in identifying the reactivation of August 2016 landslide that occurred on 22 January 2019. Thus, this study showcases the efficiency of IBIS-FM radar in monitoring slope instability with sub-millimeter accuracy on a near real-time basis.

The hydrological regime of many alpine rivers is heavily altered due hydroelectric power generation. Hydropeaking operation produces frequent and irregular discharge fluctuations. Depending on the operational changes of flow amplitude and/or upramping rate as well as on river morphology, hydropeaking can lead to quick and strong variations in hydraulic stress affecting stream invertebrates and causing increased drift. In the present flume experimental study, we analyzed trait-specific drift reactions to single and combined effects of increased flow amplitude and upramping rate. We analyzed taxa according to their hydraulic habitat preference and flow exposure, as these traits seem to be indicative toward hydropeaking. The results show that the sudden increase in discharge and related flow velocity led to increased macroinvertebrate drift proportions in hydropeaking treatments, which differed significantly to parallel control runs (mean drift proportion in all hydropeaking setups: 13% compared to 5% in controls). Increasing flow amplitudes led to an increase in drift for most taxa and traits. This was particularly significant for taxa associated with lentic areas. The effect of the up-ramping rate on macroinvertebrate drift was nonsignificant but showed strong interactive effects with the flow amplitude, especially for taxa dwelling on the substrate surface. Our results therefore indicate that dischargerelated parameters, such as flow velocity, primarily affect macroinvertebrate drift and the importance of the up-ramping rate increases, if certain discharge-related thresholds are exceeded. Vice versa, a reduction of the up-ramping rate at hydropeaking events with high flow amplitudes may reduce the effect on macroinvertebrate drift. Flow-exposed (surface) and flow-sensitive (lentic) taxa showed distinct drift reactions following hydropeaking treatments, which were significantly higher compared to effects on taxa associated to lotic and interstital habitats. Therefore, we conclude that both traits (hydraulic and vertical habitat preference) have proven as promising for analyzing hydropeaking effects. The trait classifications should be extended to a higher number of taxa and to different life stages as these may show different drift patterns.

The use of renewable energy has been an important topic in the four Pacific Northwestern states for the last 30 years. Large, statistically designed public surveys were conducted in the region in 1990, 2000, 2010, and 2020 to determine the perceived sustainability, future viability, and acceptance of the following ten energy sources: biomass, coal, geothermal, hydropower, natural gas, nuclear, oil, solar, tidal, and wind power. The survey questions were identical in all 4 years of the survey. These surveys were delivered by the US Postal Service to over 3500 randomly chosen residents in each survey year. The public response rate exceeded 50% in each survey year. Demographic data about age, gender, education level, community size, and state of residence of survey respondents were also collected. The survey data were statistically analyzed. In general, the public was literate identifying the renewable and nonrenewable energy sources as the majority of survey respondents correctly identified biomass, geothermal, hydropower, solar, and wind as renewable energy sources. Based on survey results, over 75% of Pacific Northwest residents considered it important or very important that their energy resources were renewable in 2020. The findings of this study were important because it shows that the public is in line with the scientific community with the goal of greatly reducing energy reliance on C containing nonrenewable energy sources including oil, coal, and natural gas. In summary, (1) the public strongly supports the transformation to a sustainable energy system using primarily renewable energy sources, (2) the use of traditional nonrenewable energy sources like natural gas should not be discouraged in the present; however, they should be phased out over the short and medium terms, (3) solar and wind energy should be significant sources to meet future energy needs in the region, and (4) the renewables including biomass and geothermal have a place in the future energy mix within the Pacific Northwest.

We investigated the ecohydraulic effects of a recently implemented hydropeaking mitigation measure in the Upper Noce Stream (NE Italy, Italian Alps), which also allows for additional hydropower production. The Upper Noce, a 3rd order gravel-bed stream, was affected since the mid-1920s by storage hydropower production and associated hydropeaking. The mitigation measure consisted in the diversion of most of the released hydropeaks into a sequence of three newly-installed, cascading run-of-the-river power plants, fed by a penstock running almost parallel to the former hydropeaking reach. The hydropeaking-diversion mitigation measure markedly reduced hydropeaking on a 10-km stream reach, and hydropeaking is now released immediately upstream the confluence with a major free-flowing tributary, which increases the hydropeaking baseflow. The flow regime in the mitigated reach shifted from hydropeaking-dominated to baseflow-dominated regime in winter, with flow variability represented only by snowmelt and rainfall in late spring and summer. We applied two sets of indicators (the Hydropeaking Indicators HP1, HP2 and the COSH method) and conducted a simplified hydraulic analysis of the hydropeaking wave propagation. We assessed the ecological effects of the mitigation measure using three complementary data sources: the analysis of (a) the benthic and (b) hyporheic invertebrate communities, based on datasets collected before and after the implementation of the diversion measure, and (c) ancillary data monitored by the diversion plant manager for required environmental monitoring, which included the suspended sediment regime and the Extended Biotic Index, measured yearly from the year before to the four subsequent years after the implementation of the mitigation measure.Three main changes in eco-hydraulic processes associated with hydropeaking mitigation were detected. i) The flow regime in the mitigated reach changed to a residual flow type, with much less frequent residual hydropeaks, with an average two-fold increase in downramping rates that were recorded downstream the junction with a major tributary. ii) The functional composition of the macrobenthic communities shifted slightly in response to flow mitigation, but the taxonomic composition did not recover to conditions typical of more natural flow regimes. This was likely due to the reduced dilution of pollutants and resulting slight worsening in water quality. iii) The hyporheic communities conversely showed an increase in diversity and abundance of interstitial taxa, especially in the sites most affected by hydropeaking, and this effect was likely due to changes in the interstitial space availability, brought by an alteration of the previous time-space pattern of fine sediment transport, which eventually resulted in reduction of fine sediments clogging of the gravel bed interstices.Besides illustrating a feasible hydropeaking mitigation option for Alpine streams, this work suggests the importance of monitoring both benthic and hyporheic communities, together with the flow and sediment supply regimes, and physico-chemical water quality parameters, for carefully detecting changes in eco-hydraulic processes associated with hydropeaking mitigation that may not be fully expected in the design phase.

Human activities, principally through emissions of greenhouse gasses (GHGs), have unequivocally caused global warming, with global surface temperature reaching 1.1 °C above pre-industrial (1850–1900) levels in 2011–2020, precipitating widespread and rapid changes in the atmosphere, ocean, cryosphere, and biosphere. To mitigate escalating climate change effects, the Paris Agreement calls for limiting global warming to no more than 1.5 °C; IPCC global modeled pathways which achieve this goal reach net-zero CO2 emissions by 2050. Deep decarbonization efforts in pursuit of net-zero emissions should be especially prioritized within the energy sector which is responsible for approximately two-thirds of global CO2 emissions. However, increased deployment of weather-dependent renewable energy sources like wind and solar will make the energy supply more variable and out of phase with demand. This research pertains to two load-balancing energy sources capable of increasing grid stability and enabling the transition to renewable energy: hydropower and nuclear energy. My capstone research examines the Columbia River Basin—which provides more than 40% of total U.S. hydroelectric generation—and considers the effects adapting hydropower operations for greater load balancing on the region’s ability to sustain environmental flows for wildlife and ensure sufficient water supply and flood protection. The study uses the Borg multi-objective optimization algorithm in combination with the California and West Coast Power Systems model and a reservoir simulation model to design alternative reservoir operating rules that balance these conflicting objectives. This optimization additionally considers the human and social dimensions of dam operation, as changes in streamflow temperatures from re-designed operating policies can significantly affect salmon and steelhead populations and by extension the local Native American groups who rely on them. My STS research applies the social construction of technology framework to examine the historical adoption of nuclear energy in the United States as well as assess the potential of nuclear energy to facilitate the transition to a carbon-neutral energy sector. I analyze current U.S. energy and climate initiatives to find discrepancies between renewable and nuclear energy policies and compare the projected low and decreasing adoption of nuclear energy which results from these policies with the levels modeled in net-zero emissions studies by Breakthrough Institute, Princeton University, Vibrant Clean Energy, and Williams et al. (2021). Ultimately, I explain the dichotomy between projected and net-zero nuclear deployment with poor project management and a lack of enabling legislative policies which create a reinforcing loop that makes nuclear energy prohibitively expensive as an investment. These two areas of research in conjunction aim to improve the feasibility of cost-efficient net-zero emissions pathways.

The Earth is warming due to the burning of fossil fuels, leading to a growing interest in renewable energy sources such as solar, wind, and hydropower. Hydropower plays a vital role in meeting global carbon mitigation targets, especially in the Mid-Columbia (Mid-C) energy market in the Pacific Northwest (PNW), where it currently comprises 50-65% of generation. However, with other renewable energy sources expanding, such as solar power in California (CA), hydropower operations at plants within the connected Mid-C market need to be modified to balance the more intermittent supply from renewables in CA. Our technical project aims to redesign hydropower operations in the Columbia River Basin (CRB) of the PNW to achieve a 95% renewable energy power grid in CA and the PNW by 2035, balancing objectives such as minimizing environmental spill violations, maximizing hydropower production, maximizing flood protection, and maximizing economic benefits through multi-objective optimization. The Columbia River Basin, which spans over an area of 260,000 square miles, is a significant watershed in the United States that is solely dedicated to the Columbia River. It serves as the drainage system for numerous rivers, creeks, and streams. In the 1930s, the federal government began constructing dams along this river for various purposes such as preventing floods, generating hydroelectric power, supplying water for irrigation, creating locks for navigation of boats and barges, and developing recreational areas. However, the hydropower operations and the construction of dams in the Columbia River Basin have resulted in significant environmental and social impacts, including the reduction of accessibility to salmon populations and disruption to the way of life of Indigenous populations who have relied on these lands, the Columbia River, and the salmon for centuries. The government has implicitly relied on technological determinism, sacrificing the humanitarian rights of Native Americans for the sake of hydropower advancement, while simultaneously achieving progress on their economic and environmental objectives for the larger American population who rely on the dams and the power grid. My STS research seeks to draw upon hydropower legislation and policy analyses in a global context to argue for successful approaches and frameworks for hydropower policy going forward in the California River Basin that ensure the rights and survival of Native American tribes in the region. A multi-stakeholder process in the context of hydropower in California could provide a valuable precedent for addressing the needs of multiple social groups and constituents in the future. Both projects enable me to explore how the United States can make systemic changes, motivated by the current state of the hydropower and energy sector, to balance multiple competing interests and stakeholders in the Columbia River Basin. For our technical project, we focused on adapting hydropower operations to support renewable energy transitions and freshwater sustainability in the Columbia River Basin. Achieving net-zero energy sector emissions requires rapid adoption of renewable alternatives to existing high-emissions infrastructure. The on-demand energy from hydropower uniquely facilitates the transition to renewable energy by meeting demands not met by weather-dependent energy sources like wind and solar. Because there are conflicting tradeoffs in hydropower operating policies, it was necessary for us to perform a multi-objective optimization after we had simulated the operations of reservoirs in the Columbia River Basin which serve as the supply of water for hydropower in the region. Our case study focused on designing operations at four reservoirs in the Columbia River Basin to balance environmental and economic objectives under potential future energy and climate conditions. These reservoirs included Hungry Horse, Libby, Dworshak, and Grand Coulee. Our objectives were to minimize environmental spill violations, minimize peak flood height, minimize flood frequency, maximize hydropower production, and maximize Bonneville Power Administration (BPA) revenue. We performed multi-objective optimization to design alternative reservoir operating rules that balance these conflicting objectives. We made use of two computational models – a power systems model for generating electricity prices from synthetic weather data to represent regional wind, solar, and hydropower capacities and a reservoir optimization model for generating optimal policies that balance the objectives. These models are coupled through the objective of maximizing the BPA revenue in our reservoir optimization, since calculating that revenue requires the electricity prices in the region. Our optimization model yielded nineteen non-dominated reservoir operating policies that dictate when to release water using parameters such as the previous day’s inflow and the storage of the reservoir. To evaluate the robustness of these policies and account for uncertainty, we simulated the outputted policies over four climate change scenarios and an energy scenario inspired by the National Renewable Energy Laboratory’s (NREL) Mid-Case with 95% Renewables by 2035. The climate change scenarios we used were futures that are dry with high warming, dry with low warming, wet with high warming, and wet with low warming. Furthermore, the energy scenario we selected describes the projected distribution of energy across renewable sources for the years 2025, 2030, and 2035. In the end, we selected one optimal policy out of the nineteen which had the least significant tradeoff between the objectives. It effectively maximized hydropower output and BPA revenue, while minimizing spills, flood height, and flood risk. In this policy, the Dworshak reservoir is used for flood protection and all policies chose to keep Grand Coulee reservoir full to maximize hydropower production. Thus, through multi-objective optimization and scenario analysis, we were able to find alternative reservoir operations for the Columbia River Basin that balance all the system objectives and are robust to uncertainty. Future work should explore how uncertainties in energy and climate interact rather than their independent influences and optimize policies across these possible futures to improve performance. For my STS project, I focused on developing potential public policy to uplift Native American tribes affected by hydropower in the Columbia River Basin. The ongoing operations of dams in the Columbia River Basin have negatively impacted salmon populations, disrupting the traditional way of life and culture of Indigenous populations who rely on salmon as a staple food and cultural symbol. The construction of these dams between the 1930s and 1980s also resulted in the displacement and loss of Native American territory, leaving tribes living in federally assigned settlements with unsafe living conditions. The heavy use of the Columbia River has caused significant declines in water quality and threatens the survival of species like salmon. The negative impacts have disproportionately affected Indigenous tribes in the region, including the Nez Perce, Warm Springs, Yakama, and Umatilla tribes who settled with the federal government for their lost sites. Notable legislation that has been enacted thus far to address the environmental disruptions to salmon populations and displacement of Native Americans include the Northwest Power Act of 1980, the Columbia Basin Water Transactions Program of 2002, the Army Corps of Engineers’ development of more permanent housing for Native Americans under the Obama Administration in 2016, the Water Infrastructure Improvements for the Nation Act of 2016, and the Biden-Harris Administration’s ongoing litigation with Indigenous tribes in the Columbia River Basin regarding salmon populations. Members of Congress and the US Department of Energy admit that inefficiencies in hydropower licensing processes are causing higher development costs and longer timelines which reduce the flexibility of the government to perform stakeholder analyses. Thus, the effects of hydropower operations on fisheries, recreation, and tribal and public lands are not being considered by the federal government. A framework I discovered in the academic literature on hydropower policy both domestically and internationally that can be applied to the case of Native Americans in the Columbia River Basin is the political ecology framework. In the paper—"Discussing Large Dams in Asia After the World Commission on Dams: Is a Political Ecology Approach the Way Forward?"—the authors present this framework which is characterized by the following: the framework examines the effects of large dams as well as the causes (economic and political motivations), it requires that ecological structures and functions be coupled with social, political, cultural, and economic influences, and it incorporates an actor-oriented model to look at environmental change and land-use conflicts that are occurring within politicized environments. In their paper, they analyze the case of the Bhakra Dam in India using this framework and comment on the social, political, and economic motivations behind the dam that are not immediately evident. An important similarity between the Bhakra Dam case and the Columbia River Basin case is the issue of arbitrary demarcations of land. The Bhakra Dam was built by India in a disputed territory with Pakistan called Punjab. Furthermore, India hindered Pakistan’s use of the Sutlej river which ran through both countries to construct the dam. In the Columbia River Basin case, Native Americans do not own the land they reside on—rather it is held ‘in trust’ by the federal government making it an arbitrary demarcation. Therefore, I pose two potential solutions using the framework of political ecology in the Columbia River Basin case—award property rights to Native Americans and design new licensing processes for hydropower. By giving Native Americans property rights, they have equity in the land and can therefore reap monetary benefits and power by selling it or cultivating the natural resources on it. With their own source of money, they can take charge over environmental restoration and uplifting the Native American community alongside the federal government instead of being dependent on the government for change to occur. By designing new licensing processes for hydropower, this enables the federal government to place reasonable conditions on hydropower licenses and protect tribal and public lands, safeguard water quality, and fishery resources.

Greenhouse gas emissions from non-renewable energy sources are growing at an alarming rate, causing extreme temperatures and climate conditions to occur; engineers must create and refine energy systems to protect the environment, as well as the general public, by expanding the use of renewable energy sources. The technical research consists of developing a 100% clean hydroelectric system for the Columbia River Basin. Our designed system effectively maximizes hydropower output and economic benefits, while also minimizing environmental consequences. The STS research deals with the social effects of dam construction and hydropower operations on local Native American tribes and communities. Specifically referring to the construction of the original hydroelectric system in the Columbia River Basin which caused thousands of tribe members to relocate, permanently altered their homes and sacred areas, as well as negatively affected their way of life and food sources. The technical and STS research are directly coupled, because in redesigning this area to be more environmentally friendly, I am preserving the region’s landscape and ecology as well as protecting salmon and steelhead populations – important aspects of Native American daily life and culture. In order to create a long-lasting energy model, my team produced a system that is economically beneficial, environmentally safe, and socially conscious. To effectively re-model the design of alternative hydropower operations in the Columbia River Basin for a more renewable grid, my technical research team ran two loosely-coupled models: the California Power Systems model (CAPOW) and a reservoir systems model. These models have 1000 years of synthetically generated weather and energy mixes as their inputs and additional components within them, such as the streamflow temperature model, the Vancouver water level model, and an electricity price model that emulates the power system model output. This entire model generates a series of outputs, including reservoir operations that maximize hydropower output and BPA revenue, in addition to minimizing environmental spills violations, peak flood height, and moderate flood frequency. These operations are optimized by a multi-objective evolutionary algorithm that finds different policies that trade-off performance on these objectives in different ways. The multi-objective optimization yielded 19 alternative reservoir operating policies whose performance we evaluated across three climate scenarios. After the generation of parallel axis multi-objective tradeoff plots, policy 10 was selected as the optimal policy because it has the least significant tradeoff between my model’s objective functions, including maximizing BPA revenue and hydropower output, while minimizing environmental spills, flood height, and flood frequency. The STS research question is: how do we ensure that the construction of dams and other hydropower systems does not overwhelmingly alter the lives of those living in communities near these structures while still producing ample energy? In order to answer this question, I developed an STS framework based on Pinch and Bijkers’ “Social Construction of Technology Model.” This framework requires engineers to evaluate the social consequences of their hydropower design and re-evaluate their model if these consequences are too great. In my project, I wanted to combat the noted issues of interference in Native American culture in addition to the ecological costs of hydroelectric systems. Therefore, I developed a system including the design’s effects on fish populations, community layout, local waterways and landscape, and sacred tribal grounds. Supporting my framework detailed above, there are several concrete solutions that I developed in order to effectively evaluate my hydroelectric system. First, I developed a streamflow temperature model, which predicts future streamflow levels and temperatures and identifies times when hydropower operations would cause unsuitable habitats for migrating salmon so preventative measures can occur. Secondly, I did extensive academic research on the historical effects of the original Columbia River Basin construction on local tribes, such as community relocations and tribal grounds destruction. Therefore, in future developments, these same mistakes can be avoided through fair communications in the planning process and reforms to the already existing Columbia River Treaty. Lastly, monitoring and predicting flood heights and frequencies at influential reservoirs will ensure public safety for these communities as well as protect local waterways and landscapes. The expansion of hydroelectric systems is essential to combat global climate change, but it is important to understand the drastic social effects these systems can have. As seen in the Columbia River Basins, dozens of tribes and thousands of Native Americans’ home lives and traditions were permanently altered. In order to create a better future, engineers have an overarching responsibility to society to make innovative and equitable technology systems.

While the construction of pump storage facilities can improve the reliability of the electricity grid by balancing supply and demand, it can also have negative impacts that disproportionately affect underrepresented communities. One such example is the Native American tribes who were displaced by the construction and operation of the Grand Coulee Dam in Washington, U.S.A. The technical aspect of this research project aims to derive a hydropower-based solution to enable 100% clean energy in the Columbia River Basin through a case study analysis of the Grand Coulee Dam. This decarbonization solution must have a large enough energy production to balance the needs of consumers and businesses while minimizing disruptions to local ecosystems and waterways of the Pacific Northwest. This is particularly important because underrepresented communities often have no say in the decisions like constructing and operating large infrastructure like a hydropower power plant, suffer the brunt of the changes caused by this infrastructure, and don’t reap any of the resulting economic or social benefits. Star’s definition of infrastructure and its properties can guide the case study analysis. The properties of interest for the Grand Coulee Dam are its embeddedness, reach or scope, and how it is built on an installed base. This research investigated the socio-economic implications of the dam by identifying points of convergence and divergence in the accounts put forth by the afflicted tribes and the governing federal agencies. This produced a baseline of truth for a more three-dimensional analysis of the dam’s impacts on these communities. By better understanding how these tribes were disproportionately impacted by the operation of the Grand Coulee Dam, the aforementioned hydropower-based solution can be designed to ensure the communities’ protection and ongoing livelihood.

In-pipe water turbines have begun to gain interest for harvesting power on a small scale from pipe networks. However, few studies have addressed the feasibility of installing spherical lift-based helical-bladed turbines in a water supply network. Points such as the pressure drop and generated power remain unexplored. In this study, a three-dimensional numerical model, based on OpenFOAM, is used to investigate the performance of the spherical lift-based helical-bladed in-pipe water turbine. The study aims to evaluate how the geometric properties of this turbine affect its performance in terms of power and efficiency, and the hydraulics of pipe flow in terms of pressure drop. The study considers a turbine of diameter 600 mm, with the following geometric properties: number of helical blades 3, 4 and 5; blade chord length 10%, 15% and 20% of turbine diameter D; blade helicity 0°, 60° and 120°; and pitch angle −6°, −3°, 0° and 3°. These parameters are analyzed at tip speed ratios (TSRs) of 2, 3 and 4. The results show that the five-blade turbine yields a power of 1300 W, while the three-blade turbine yields only 870 W, at an optimum TSR of 3. A change in the chord length of 50% (from 0.10D to 0.15D) increases the turbine power by 88.4% and efficiency by 40% for the same TSR. A further change to 0.20D gives no significant improvement in efficiency or power output. An increase in the helical angle from 0° to 120° results in a 22.8% reduction in turbine power. The turbine achieves the maximum power output of 1350 W at zero pitch angle, with a corresponding efficiency of 27%. The maximum head loss observed is 1.6 m, which represents 2.7% of the total head in the pipe. Solidity has a more pronounced effect on head losses than helicity and pitch angle.

In the context of Water Framework Directive (WFD) and the objective of ''good ecological status'' of European water bodies, both the idea of river continuity restoration and the river basin approach call for a scalar transformation of water governance based on ecological principles. Among the WFD literature, very few have focused on industrial actors in areas of production and their role implementing or countering these principles. To observe this, it is argued that one must first grasp the sectoral scales linked to economic actors’ practices. We define sectoral scales as the scalar issues related to industries practices and then question how they have been challenged by new environmental scalar configurations. Using case study analysis, this article focus on two industries in southwestern France in the Adour-Garonne hydrographic District, namely hydropower and irrigated agriculture. The results highlight that implementing river continuity restoration and river basin approach challenge the economic and political practices of these industries related to the spatial scope of their production process and their political jurisdiction. In the face of change, industrial actors defend “functional” perimeters for their activities by rescaling water governance in order to keep control over water resources and maintain the institutional arrangements they have forged within those boundaries. In conclusion, we suggest that research on changes of scales relating to water governance should further question economic actors and how their practices are ultimately entangled in specific scales. Only in so doing can we understand deep-rooted obstacles to the implementation of the WFD in areas of production and better grasp social and ecological interdependencies at stake.

Hydropeaking negatively affects fish assemblages, but knowledge gaps still constrain our ability to rank and mitigate the impacts of different hydropower operation regimes at particular power plants. This is especially relevant for species and rivers for which the effects of hydropeaking are less investigated, such as the Iberian Cypriniformes and Mediterranean rivers. Recognizing the potential of the hydropeaking tool method (HT) developed for salmonids to systematically assess hydropeaking impacts, we adapted it for Iberian Cypriniformes. The general tool framework developed for the salmonids was kept for the Cypriniformes, with the combined use of factors describing the hydromorphological effects and factors related with fish vulnerability to assess hydropeaking impact. Effect and vulnerability factors were developed for Iberian cyprinids and leuciscids establishing preliminary thresholds for each indicator with three different levels of hydropeaking impact on the targeted taxa. The proposed factors and thresholds were critically reviewed and ranked by experts on Iberian Cypriniformes ecology and Mediterranean rivers functioning. Overall, the timing and distribution of peaking events were ranked higher by the experts in the effect factors, whereas the population size of barbel and smaller native Cypriniformes, as well as the degree of limitations in recruitment, were ranked higher in the vulnerability factors. Although there was some divergence in the expert opinions, a final set of effect and vulnerability factors was established, that retained most of the ones proposed for the salmonids, but included new ones, particularly for vulnerability. The present study provided a comprehensive, straightforward, and systematic assessment tool for evaluating hydropeaking impacts on Iberian Cypriniformes. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 727830, http://www.fithydro.eu/

Freshwater species are particularly vulnerable to emerging threats linked to climate change because they are often already heavily impacted by habitat destruction, pollution, and exploitation. For many harvested populations of freshwater fish, these combined impacts have been mitigated for decades through stocking with captive-bred individuals. However, stocking may lead to loss of genetic variation, which may be crucial for adaptation under climate change. Exploration of sustainable alternatives is therefore paramount. We used a female-based integral projection model (IPM) to assess the consequences of terminating a long-term stocking programme for a population of landlocked, migratory brown trout Salmo trutta, and to evaluate relative effectiveness of alternative management strategies involving harvest regulations and river habitat improvement. The IPM classified individuals by body size, life history stage, and location relative to a hydropower dam, and was parameterised with 50 yr of individual-based data, supplemented with literature values. Model simulations indicated a strong population decline of 22-29% per year without stocking, much of which was attributed to high harvest mortality. Consequently, drastic reductions in fishing pressure were predicted to be necessary to ensure population viability without stocking. Mitigation measures reducing mortality associated with the hydropower dam or restoring spawning areas could further contribute to population viability when combined with changes in harvest regulations. Our results thus emphasise that large changes in management strategies, such as termination of long-term stocking programmes, require a thorough assessment of potential consequences and alternative mitigation strategies using data and models, or, at the very least, a precautionary approach under consideration of on-going climate change. Migratory salmonid · Salmo trutta · Integral projection model · Harvest · Fishing · Stocking · Dam · Hydropower · Trout

The objective of the current research is to develop a novel analytical approach for the performance evaluation and optimization of a run-of-river hydropower facility. Two types of turbines, Kaplan and Francis are considered and the analysis is validated on the basis of a new hydrological model through adopting a case study approach. In the second step of the study, a sensitivity analysis was conducted to determine the optimum energy production values of the designed hydropower system. The results of the analysis have demonstrated a high energy efficiency for both Kaplan and Francis turbines. The Francis turbine has particularly outperformed the Kaplan turbine in terms of productivity and technical performance. Optimization of the energy production for each turbine concluded that with a fixed water height ranging from a minimum of 5 m up to maximum of 20 m, the highest levels of the energy production are observed when the water speed and the net head reach larger values.

The records of suspended sediments and associated hydro-meteorology of the glacierized catchments are very limited in Sikkim Himalaya. Therefore, we carried out the first-ever estimate of suspended sediment transport from the meltwater stream of East Rathong Glacier for June-September during three consecutive melt seasons (2013–2015). These records were used to estimate the suspended sediment concentration (SSC), load (SSL), yield (SSY) and erosion rate (ER). The daily mean SSC was 105.75, 84.20, and 91.51 mg/l during melt seasons of 2013–2015 respectively. The monthly mean SSC of the combined melt season of 2013–2015 was 92.72, 107.14, 105.93 and 60.46 mg/l for June-September, respectively. The observation shows that July-August contributed to maximum SSC, accounting 70.45% of total SSC. Similarly, the monthly mean SSL for June-September was 55.64, 69.61, 65.75 and 25.72 tons, respectively. We observed high variability in SSL (CV = 0.54) than SSC (CV = 0.38) since the estimation of SSL depends on both discharge (Q) and SSC. The relationship between monthly mean SSC and Q was highly significant (R2 = 0.98) than daily SSC and Q (R2 = 0.25) due to reduced variability on a monthly scale. Further, mean SSY in the catchment was high during peak melting season (July-August), which substantially reduced during the end of the melting season. We estimated the mean SSY of 281.93 ton/yr km2 during the combined melt season (2013–2015). The average ER for the East Rathong Glacier basin was 1.04 mm/yr, which is lower than the ER of most of the Himalayan glaciers. We observed significant meteorological control of Tmean, Tmax and Rainfall in the transportation of suspended sediments from meltwater stream at a monthly scale. These in-situ based records on dynamics of suspended sediment and associated hydro-meteorological parameters are relevant for the planning and management of freshwater resources and planning for hydropower projects under a changing climate.

The hydropower sector is currently experiencing several technological developments. New technologies and sustainable practices are emerging to make hydropower more flexible and eco-friendly. Novel materials have also been recently developed to increase performance, durability, and reliability; however, no systematic discussions can be found in the literature. Therefore, in this paper, novel materials for hydropower applications are presented, and their performance, advantages, and limitations are discussed. For example, composites can reduce the weight of steel equipment by 50% to 80%, polymers and superhydrophobic materials can reduce head losses by 4% to 20%, and novel bearing materials can reduce bearing wear by 6%. These improvements determine higher efficiencies, longer life span, waste reduction, and maintenance needs, although the initial cost of some materials is not yet competitive with respect to the costs of traditional materials. The novel materials are described here based on the following categories: novel materials for turbines, dams and waterways, bearings, seals, and ocean hydropower.

Featured with fast response abilities and high ramp rates, energy storage systems (ESS), such as pumped-storage hydropower (PSH) plants and battery storage systems (BSS), are considered as key first-responders to provide spinning reserve in response to system contingencies. However, ESSs are energy-limited resources, and their sustained spinning reserve deployment is restricted by the stored energy and available capacity. Indeed, the spinning reserve deployment against contingencies may deviate actual state-of-charge (SOC) from the scheduled value, inducing potential SOC boundary violations and non-dispatchability in later hours. This paper proposes the post-contingency operation model and the spinning reserve secure constraints to address these issues. The post-contingency operation model describes that spinning reserve from ESSs is promptly deployed when contingency occurs, and then gradually substituted by quick-start units when they are switched online. By leveraging this operation strategy, spinning reserve secure constraints in terms of SOC headrooms are adopted to guarantee its deplorability. A modified IEEE 118-bus system with multiple PSHs and BSSs is used to verify the proposed approach.

Al-Marj is located about 100 km from Benghazi, and it has a rugged mountainous terrain. The grid extensionmakesit impractical in some places, and off-grid electricity the best option. In this study, the feasibility of a small hybrid electrical Micro-hydro/Photovoltaic/battery supply system for road lighting was analyzed. The reservoir's water potential is analyzed as well as meteorological data collected from NASA. The initial reservoir flow data was taken for accurate hydropower modeling located at the start of the slope by measuring the total height with the help of GPS (Geographical Positioning System) and flow data obtained from the Ministry of Water and Irrigation. The average flow rate is 0.46 m3/s. HOMER software was used to model and analyze data for a hybrid power generation system. The study included the electrical load for lighting the road with 100 poles powered by solar energy with a LED lamp. From the HOMER program result, 30 KW PV and 0.9 KW Hydro was selected. It has an initial energy cost of $0.032 per kilowatt-hour, much lower than the network system capital cost for such particular site. For a distance of more than three kilometers, the government network can use no lighting.

Fluctuation in hydro-electricity production is primarily attributed to natural and human-induced flow variations. Reduced electricity generation because of unavailability of flow inflicts significant upward pressure on the sources and prices. Despite studies on the impact of externalities on river flow variation, there is a distinct research gap on the responsiveness of hydropower plants to change in flow. This study has introduced a novel concept of flow elasticity of power ( e ) to assess the resilience of hydropower projects to flow variation. The theoretical aspect has been established for run-of-river (ROR) and storage-type (ST) cases separately and validated at two projects, one of each type, located in the Budhigandaki Basin in central Nepal. Responsiveness of hydro-projects to the topographical parameters are also dealt with here. For ROR systems, wide-ranging values of e indicate varying levels of resilience to power generation and loss of resources. For ST projects, the response differs according to emptying, filling and ROR-equivalent phases. Furthermore, strong topographical implications on power production and its elasticity are evident. This concept of e sets out a significant research contribution in the hydropower sector and demonstrates its possibility of direct application in projects in ‘priori’ as well as ‘posteriori’ while planning/designing and updating stages, respectively. The e coefficient scientifically informs the planners and developers on the sensitivity of the powerplants to hydrological variations and topography ultimately benefitting the existing global challenge to minimize the loss of precious resources for sustainable hydropower development.

Cascade hydropower plants which have good regulation performance and are managed by the dispatching center of regional power grids are usually required to simultaneously shave the peak load for multiple provincial power grids, which is an important way of relieving the growing peak shaving pressure on power grids in central and eastern China. This paper establishes an optimization model for the short-term generation scheduling of cascade hydropower plants in regional power grids. In this model, minimizing the peak-valley load difference of multiple power grids is adopted as the objective function. In addition to conventional hydraulic constraints, the operation constraints of individual hydropower units, electrical constraints and head effect on the power generation are all considered to obtain precise scheduling. The original nonlinear and non-convex model is converted into a standard mixed-integer linear programming (MILP) formulation through several linearization strategies. The results for the real-world case study indicate that: 1) the proposed model is computationally efficient with a calculation time of 326 s; 2) the peak-valley differences of the Shanghai Power Grid and Zhejiang Power Grid decreased by 9.71% and 2.29%, respectively; 3) compared with actual operation, the proposed model shows better performance in peak shaving for multiple provincial power grids.

Low-head hydropower bears tremendous potential as a renewable energy source, especially in the context of the progressing global warming. In locations with a low head, for economic and environmental reasons, a small hydropower plant with a waterwheel and an asynchronous generator may provide the best solution for sustainable electricity production. The purpose of this study is to demonstrate a new type of low-speed radial piston pump intended to be part of the hydrostatic transmission of such a small hydropower plant. The advantage of the transmission is the possibility of stepless, automatic change of the gear ratio during operation. First, we describe a mathematical model of the proposed pump and subsequently demonstrate a test stand equipped with its prototype with three suction-pressure units. The pump flow rate characteristics calculated using the theoretical model were compared with those obtained from experiments, resulting in the determination and characterization of the pump's efficiency. Supplementary experiments with a hydraulic accumulator installed as part of the investigated system, demonstrated the possibility of flow rate pulsation dampening. The experimental results showed the validity of the developed mathematical model. In conclusion, the correct operation of the pump was corroborated, and its potential application confirmed by the efficiency results.

The share of world energy consumption for electricity generation by source is primarily based on coal and natural gas. Within the last years, governments have implemented policies to promote investment in renewable energy. In Ecuador, the share of hydroelectricity has rapidly increased without regarding long-term environmental impacts. This paper aims to develop a cradle-to-gate life cycle assessment of two representative plants of Ecuador (Agoyán and Paute, with 156 MW and 1075 MW of installed capacity, respectively). The life cycle inventory contains the primary flows of energy and matter during the construction, operation, and final disposal stages, with 1 kWh as a functional unit. The life cycle impact assessment uses the CML 2000 midpoint potential categories, including Abiotic Depletion, Acidification, Eutrophication, and Global Warming. The construction stage is the leading contributor to the global impacts, and the dam the environmental hot spot of both plants, and the reservoir flooding represents the major contributor to the impact during the operation stage. Furthermore, electricity generation in plants with a larger scale can lead to fewer impacts, suggesting that constructing large-scale plants can reduce the global impacts in countries with similar hydropower potential. This methodological framework serves as a decision-making criterion for evaluating the environmental performance of other renewable energy systems.

As the worldwide energy crisis worsens, renewable energy sources have undeniably opened new horizons for our society. It will offer an efficient solution to this severe energy crisis, environmental issues and fulfilling human energy needs. Therefore, six main criteria, social, economic, quality of energy, political, technical, environmental, and sixteen sub-criteria have been employed, and an assessment model is developed for prioritizing the most pertinent renewable energy sources for electricity generation in developing countries in which four major resources, solar energy, wind energy, hydropower, and biomass energy, are considered and their electricity generation potential. Furthermore, the integrated method with the analytical hierarchy process and VIekriterijumsko KOmpromisno Rangiranje are acquired for a comprehensive assessment. The results demonstrate that the economic criterion had the highest weight of (0.353) compared to the technical criterion, which took place second with a weight of (0.244) followed by environmental (0.205) and quality of energy with a weight (0.098), respectively. The political and social criteria have the lowest weights of (0.057) and (0.043). From the review, renewable resources seem to have sufficient potential to develop a sustainable electricity system. Likewise, the model priorities these resources, revealing that hydropower is the best renewable energy source option, followed by wind energy. Biomass energy and solar energy ranked third and fourth. The assessment performed in this study can help decision-makers in Pakistan to frame long-term energy policy directing for sustainability.

The four major Chinese carp (MC), Schizothorax fish species (SF), and Cobitidae fish species (CF) are the most important target fish species in China. The swimming behaviour study of three target fish groups is the key to Chinese fishway designs. The 20 min critical swimming speed (Ucrit-20 min) and endurance of the target fish species in relation to body length, swimming speed, and water temperature were estimated using multiple linear regression. The results indicated that both fish body length and water temperature had a significant effect on swimming capability. Performance comparisons indicated that SF were remarkably strong swimmer. CF possess slightly greater swimming capability than MC. The entrance velocity of the upstream fishway should be greater than Ucrit-20 min, but less than maximum swimming speed to make the flow out of the fishway noticeable. The maximum swimming distance could be estimated using endurance model at flow velocity of 1.2 m·s–1. For the downstream-migrating juvenile fish, it was suggested that the flow velocity of turbine intake should be less than maximum sustained speed avoiding entering turbine.

The changing energy mix under the integration of wind and solar power widens the load peak-valley difference of the power grid and poses great challenges in power grid operation, especially for peak shaving. Hydropower has a crucial role to play in enabling the integration of more variable renewables. To explore a reasonable approach for the changing roles of hydropower and the development of wind and solar power in response to energy transition, a long-term typical daily aggregate model is developed for hydro-wind-solar power with peak shaving operation. Scenarios of integrated wind and solar power proportions under increasing penetrations are simulated by incrementally increasing the installed wind and solar power capacity. The model is converted to a mixed integer linear programming formulation. Groups of numerical experiments divided by influencing factors are used to analyze the complementary influence and optimization mechanisms. The results demonstrate that (1) the proposed model decouples hydro-wind-solar sources at temporal scales and conducts peak shaving effectively. (2) Different scales of wind and solar power have notable impacts on both long-term and short-term hydropower operation. (3) Developing wind and solar power in reasonable proportions could effectively utilize the complementarity and reduce hydropower output fluctuations on different time scales.

This study employs the econometrics test of endogenous structural breaks to separately investigate the changes in trends of the share of hydropower and non-hydro renewable power in electricity production for China using two separate sub-panels of data spanning from 1971 to 2015 and 1990–2015. To identify structural changes in each renewable power generation series, we apply the Bai and Perron procedure for determining structural breaks to estimate shifting-mean autoregressions and use the low frequency Fourier-type Lagrange Multiplier test to approximate the time series in a non-linear form. Through these tests, our empirical results reveal that the series under investigation are characteristic of segmented trend stationary processes around four or one structural breaks, among which, there are two upward shifts in the 45-year series of hydroelectricity generation occurring in 1978 and 2008, respectively. Meanwhile, one upward shift is identified in the 26-years series of non-hydro renewable generation occurring in 2005. The patterns in the timing of structural changes are suggestive of the causal effects from the recent regulatory shocks and policy change. In the present study, we conduct an innovative attempt to reveal the relevance of renewable energy and policy changes, which may also provide some empirical value in investigating the effect of policy series on renewable energy in other countries.

Energy efficiency interventions in Water Supply Systems (WSSs) need a precise evaluation of the available water flow rates for energy recovery interventions; however, flow meters are generally too costly for being installed in all the gravity adduction pipelines of a WSS. This paper presents a methodology for predicting flow rates in gravity adduction pipelines based on the electricity bill consumption. In this study, the predicted average flow rate is 0.0300 m3∗s−1, being 1.64% lower than the real one. A Pelton turbine has been chosen as energy recovery unit for supplying electricity to a pumping station of a preloading tank where the water is treated to make it drinkable. An energy saving of 475.26 (MW∗h)∗year−1 is achieved, which can be also expressed as 88.87 saved Tonnes of Oil Equivalent (TOE) and 204.36 ktCO2 not released into the atmosphere. The gross economic saving due to the installation of the Pelton turbine is equal to 94.29 k€∗year−1 and it can be further increased up to 116.51 k€∗year−1 if the energy efficiency certificates issued by the Italian Authorities are considered. The Payback Period (PBP) of the intervention corresponds to 3 years, and a Net Present Value (NPV) after twenty years is approximately 1.4 M€.

This paper focused on the stable operation and control strategy of the hydro-turbine governing system (HTGS) in an isolated-grid operation mode. The stable operation of a hydropower station in isolated-grid operation mode is important for the safe operation of a power system. A regional power grid can be isolated from a main grid due to factors such as natural disasters, grid failures, and human errors. The Lunzua hydropower station in Zambia is often forced to operate as an isolated grid. To ensure its safe and stable operation, we conducted isolated-grid regulation tests in conjunction with field testing of HTGS and determined the parameters of the HTGS for stable operation of the isolated grid. In the field test, we first set the no-load and initial parameters for the isolated-grid mode through the no-load disturbance tests. Through simulated isolated-grid operation tests, we verified and further tuned the initial parameters. Meanwhile, we propose a control strategy for the transition between large-grid and isolated-grid modes. Through operational tests, we determined the parameters for stable operation in isolated-grid mode. During testing, we found that the water flow inertia time constant Tw was too large and the inertial time constant Ta of the impulsive generator was too small, which resulted in a narrow stability range of proportional–integral–derivative (PID) controller parameters for isolated-grid operation. The governing stability for isolated-grid operation was thus sensitive to the PID parameters. Since the isolated-grid field operation test of the HTGS of the Lunzua hydropower station was completed in August 2016, the generator units have maintained safe and stable operation in large-grid and isolated-grid modes, which validated the isolated-grid operation parameters and control strategy for the transition between large-grid and isolated-grid modes as determined by our test method. The methods of field test and control strategies used for isolated-grid operation have important practical value for the isolated grid operation of hydropower stations.

Extreme weather lasting for 5–15 days not only brings large inflows in the medium-term but also causes sharp fluctuations in the daytime load of the power grid which imposes considerable challenges to the modeling and solving of medium-term power grid scheduling. The complex nonlinear constraints and water delay times of cascade hydropower plants significantly increase the difficulty of finding solutions. Hence, this study first advocates an accurate optimization model for determining the medium-term peak shaving operation of cascade hydropower plants considering the water delay time. The objective is to minimize the variance of the remaining load and maximize energy production that aims to regulate the load fluctuation and enhance hydropower efficiency. Then, to describe the water delay time of cascade hydropower plants, a piecewise delay time method (PDTM) is proposed based on the water balance equation. Finally, cascade comprehensive benefits (CCB) are established to alleviate the deviations from the scheduling plan and actual plan affected by the lag time. The developed model is implemented on the eleven cascade hydropower plants of the Lancang River in China. Simulation results demonstrate that the model is able to provide more realistic and executable generation scheduling while obtaining larger hydropower generation benefits and good peak shaving performance.

Hydropower is one environmentally friendly option for meeting these energy demands. Because such technologies do not require a weir or a dam, they may be used with minimal environmental effect. The drag-based Savonius turbine is characterized by working at low-flow speeds which fits well the natural water streams. In spite of its simple and robust design, the Savonius turbine suffers from low efficiency and high static torque fluctuations. In view of this, CFD-based optimization is applied to a Savonius-type hydrokinetic turbine inspired by a couple of swimming Koi fish. The two main design parameters; overlap ratio and gap ratio are used in this paper to define the gap between the blades. The maximum power coefficient can be obtained by employing an evolution strategy optimization technique over the constructed metamodel. The results revealed that the optimal design for the bio-inspired Savonius hydrokinetic turbine corresponds to overlap and gap ratios of 0.2085 and 0.0057, respectively. The optimal configuration generates a maximum power coefficient of 0.2521, which is 17.6% higher than that for a conventional shape at the same tip speed ratio. The new bio-inspired design performs better than the conventional Savonius hydrokinetic turbine for the considered operating range.

Private sector actors are taking on an increasingly prominent role in energy transitions, including in hydropower development and finance. Yet, there is little empirical research on the topic. This study covers private sector views on accelerating hydropower investment in Nepal, using Q methodology. Three main viewpoints were identified among 17 interviewed hydropower developers, planners, and investors based in Nepal: 1) Efforts need to be focused on reforming hydropower policies and administration at the national level; 2) Funds for hydropower development need to be increased and sought from a diversity of domestic and foreign private sources; 3) Nepal needs to integrate its energy grid with its South Asian neighbours, starting with India. Areas of strong disagreement include the role of political stability in enabling hydropower development, as well as modes of engagement with Indian, Chinese, and Western partners. Areas of consensus include the need to smoothen land acquisition procedures as well as discomfort with the state-owned Nepal Electricity Authority’s perceived monopolistic status in the sector. Overall, this study contributes to debates on private sector involvement in hydropower development with a nuanced empirical assessment of views which contain clear visions for an independent and domestically driven future of the country’s hydropower sector. Postprint

It is increasingly important to know the water quality of a reservoir, given the prospect of an environment poor in water reserves, which are based on intense and short-lived precipitation events. In this work, vegetation indices (NDVI, EVI) and bio-physical parameters of the vegetation (LAI, FC), meteorological variables, and hydrological data are considered as possible drivers of the spatial and temporal variability of water quality (WQ) of the Banja reservoir (Albania). Sentinel-2 and Landsat 8/9 images are analyzed to derive WQ parameters and vegetation properties, while the HYPE model provides hydrological variables. Timeseries of the considered variables are examined using graphical and statistical methods and correlations among the variables are computed for a five-year period (2016–2022). The added-value of integrating earth observation derived data is demonstrated in the analysis of specific time periods or precipitation events. Significant positive correlations are found between water turbidity and hydrological parameters such as river discharge or runoff (0.55 and 0.40, respectively), while negative correlations are found between water turbidity and vegetation descriptors (􀀀0.48 to 􀀀0.56). The possibility of having easy-to-use tools (e.g., web portal) for the analysis of multi-source data in an interactive way, facilitates the planning of hydroelectric plants management operations.

Представлены данные Всемирного сообщества возобновляемой энергетики 21-го века REN21 и Института экологических технологий AEE INTEC (Австрия), Международной ассоциации гидроэнергетики. В 2021 году в электрогенерации на основе ВИЭ отмечено лидерство гидроэнергетики (1360 ГВт, 4250 ТВт·ч/год); на втором месте ветроэнергетика (845 ГВт, 1980 ТВт·ч/год); далее солнечная энергетика (942 ГВт, 1138 ТВт·ч/год); биоэнергетика (143 ГВт, 602 ТВт·ч/год); геотермальная энергетика (16 ГВт, 105 ТВт·ч/год). В теплогенерации на основе ВИЭ на первом месте энергия биомассы (3892 ТВт·ч/год); солнечное теплоснабжение (522 ГВт, 425 ТВт·ч/год); геотермальное теплоснабжение (108 ГВт, 284 ТВт·ч/год). В России на 01.01.2022 г. установленная мощность и выработка электрической энергии для всех электростанций страны составляли соответственно: 246,6 ГВт (100%) и 1114,5 ТВт·ч/год (100%); в том числе ГЭС — 50 ГВт (20,26%) и 209,52 ТВт·ч/год (18,8%), СЭС — 1,96 ГВт (0,8%) и 2,25 ТВт·ч/год (0,2%); ВЭС — 2,035 ГВт (0,83%) и 3,62 ТВт·ч/год (0,35%). Общая установленная мощность возобновляемой энергетики (ВЭ) РФ составила 54 ГВт (20,9%), выработка электрической энергии — 210,76 ТВт·ч/год (20,1%) при выработке в 2021 г. всеми электростанциями России 1047 ТВт·ч/год (100%). Описано состояние российского рынка ВЭ, роль правительства в его формировании и регулировании. Представлены результаты деятельности в 2021 г. малой гидроэнергетики (1220 МВт), солнечного теплоснабжения (70 МВт), геотермальной энергетики (электрогенерации — 84 МВт, 428 тыс. МВт·ч/год; теплогенерации — 110 МВт, 280 тыс. МВт·ч/год), БиоЭС — 65,2 ГВт·ч/год, биотеплогенерации — 29,8 ТВт·ч/год., The data elaborated by the Renewable Energy Policy Network for the 21st Century REN21 and the Institute of Sustainable Technologies AEE INTEC (Austria), the International Hydropower Association are presented. In 2021, the leadership of hydropower was noted in RE generation (1360 GW, 4,250 TWh/year); wind energy (845 GW, 1,980 TWh/year) was in second place; then solar energy (942 GW, 1,138 TWh/year); bioenergy (143 GW, 602 TWh/year); geothermal energy (16 GW, 105 TWh/year). In heat generation based on RES, biomass energy is in the first place (3,892 TWh/year); solar heat supply (522 GW, 425 TWh/year); geothermal heat supply (108 GW, 284 TWh/year). In Russia, as of 01.01.2022, the installed capacity and electricity generation for all power plants in the country were, respectively: 246.6 GW (100%) and 1114.5 TWh/year (100%); including hydroelectric power plants — 50 GW (20.26%) and 209.52 TWh/year (18.8%), PPS — 1.96 GW (0.8%) and 2.25 TWh/year (0.2%); WPP — 2.035 GW (0.83%) and 3.62 TWh/year (0.35%). The total installed capacity of RE of the Russian Federation was 54 GW (20.9%), the generation of electric energy was 210.76 TWh/year (20.1%) when generated in 2021 all power plants in Russia 1,047 TWh/year (100%). The state of the Russian renewable energy market, the role of the government in its formation and regulation is described. The results of the activities in 2021 of small hydropower (1,220 MW), solar heat supply (70 MW), geothermal energy (power generation — 84 MW, 428,000 MWh/year; heat generation — 110 MW, 280,000 MWh/year), bioelectric power — 65.2 GWh/year, bioteplogeneration are presented — 29.8 TWh/year.

Starptautiskais bizness un ilgtspējīga ekonomika Vadība, administrēšana un nekustamo īpašumu pārvaldība International Business and Sustainable Economy Management, Administration and Real Estate Management Bakalaura darba tēma " Atjaunojamo energoresursu izmantošana Latvijas ilgtspējīgas attīstības nodrošināšana" šobrīd ir aktuāla, jo energoresursi tiek izmantoti katru dienu un gandrīz visur, mēs ikdienā saskaramies ar tiem visās dzīves jomās un nu jau tie ir kļuvuši par neatņemamu sabiedrības un dzīves sastāvdaļu. Šobrīd pasaulē visplašāk izmantotie energoresursi ir fosilie kurināmie energoresursi, bet to iegūšana un izmantošana izdala milzīgu daudzumu kaitīgu un siltumnīcefektu izraisošu gāzu un atkritumu, kas kaitē gan cilvēkiem, gan apkārtējai videi. Šie notikumi ne tikai apdraud mūs un mūsu vajadzību nodrošināšanu, bet tie arī liedz nākošo paaudžu iespējas nodrošināt viņu vajadzības. Ilgtspējība īpaši skar atjaunojamos energoresursus, jo šobrīd tieši tie ir galvenie ilgtspējīgas attīstības veicinātāji. Latvijā un pasaulē tiek nosprausti, veidoti dažādi mērķi un plāni, kas veicinātu ilgtspējīgu attīstību un veiksmīgu atjaunojamo energoresursu izmantošanu. Bakalaura darba mērķis ir, balstoties uz teorētiskajām atziņām par atjaunojamo energoresursu izmantošanu un empīrisko datu analīzi, izstrādāt ieteikumus atjaunojamo energoresursu izmantošanai Latvijā. Darbs tiek strukturēts 3 daļās, pirmajā daļā tiek izmantota monogrāfiskā metode, lai analizētu teorētiskos aspektus par atjaunojamiem energoresursiem, otrajā daļā tiek izmantotas sekundāro datu analīzes metode, kontentanalīzes metode un grafiskā metode, lai pētītu atjaunojamo energoresursu izmantošanas ietekmi uz Latvijas ilgtspējīgu attīstību. Trešajā nodaļā izmantota kvantitatīvā pētījuma metode, lai identificētu priekšrocības un trūkumus atjaunojamo energoresursu izmantošanā Latvijā. Pētījumā secināts, ka atjaunojamo energoresursu izmantošana Latvijā ir virs vidējā līmeņa un tie tiek izmantoti gandrīz efektīvi. Latvijas atjaunojamo energoresursu gala patēriņš ir augstāks, kā Eiropas Savienības vidējas gala patēriņš. Atjaunojamo energoresursu izmantošanai ilgtspējīgas attīstības kontekstā ir vairāk priekšrocību nekā trūkumu un galvenās priekšrocības ir energoresursu atjaunojamība, enerģijas avota neatkarība un mazināta ietekme uz apkārtējo vidi. Sabiedrības izglītošana un atjaunojamo energoresursu popularizēšana sabiedrībā ir pirmais solis ilgtspējīgas attīstības virzienā . Daži no galvenajiem ilgtspējīgas attīstības mērķiem Latvijā ir saules enerģijas attīstīšana un plašāka izmantošana, tāpat arī vēja enerģijas potenciāla izmantošana ir viens no galvenajiem ilgtspējīgas attīstības mērķiem. Darbā izvirzītie priekšlikumi ietver atjaunojamo energoresursu infrastruktūras attīstību, sabiedrības izglītošana un atjaunojamo energoresursu popularizēšanu, saules parku attīstīšanu un saules enerģijas plašāku izmantošanu, vēja enerģijas potenciāla izmantošanu un jūras vēja parku attīstīšanu, enerģētiskās neatkarības veicināšanu un energoresursu diversifikāciju. Darba kopējais lappušu skaits – 60 lpp, literatūras avotu skaits – 43, pielikumu skaits – 1 The topic of the bachelor's thesis "The use of renewable energy resources, ensuring the sustainable development of Latvia" is currently relevant, because energy resources are used every day and everywhere, we encounter them in all areas of life, and they have already become an integral part of society and our life. Currently, the most widely used energy resources in the world are fossil fuel energy resources, but their usage emits huge amount of harmful greenhouse gases, which harm both people and the surrounding environment. These developments not only threaten us and the provision of our needs, but they also deny future generations the ability to provide for their own needs. Sustainability particularly affects renewable energy resources, as they are currently the main promoters of sustainable development. In Latvia and around the world, various goals and plans are being set and created, which would promote sustainable development and the successful use of renewable energy resources. The aim of the bachelor's thesis is to develop recommendations for the use of renewable energy resources in Latvia, based on theoretical knowledge about the use of renewable energy resources and empirical data analysis. The work is structured in 3 parts, the first part uses monographic method to analyze the theoretical aspects of renewable energy resources, second part uses secondary data analysis method, content analysis method and graphic method to study the impact of the use of renewable energy resources on the sustainable development of Latvia. Third chapter uses quantitative research method to identify advantages and disadvantages in the use of renewable energy resources in Latvia. The study concluded that the use of renewable energy resources in Latvia is above average, and they are used with medium efficiently. Latvia's consumption of renewable energy resources is higher than the average consumption of the European Union. The use of renewable energy resources in the context of sustainable development has more advantages than disadvantages and the main advantages are the renewability of energy resources, the independence of the energy source and reduced impact on the surrounding environment. Public education and promotion of renewable energy resources in society is the first step towards sustainable development. Some of the main goals of sustainable development in Latvia is the development and wider use of solar energy, and the use of wind energy potential is also one of the main goals of sustainable development. The proposals put forward in the paper include the development of renewable energy resources infrastructure, public education and promotion of renewable energy resources, development of solar parks and wider use of solar energy, use of wind energy potential and development of offshore wind parks, promotion of energy independence and diversification of energy resources. Total number of pages - 60 pages, literature sources - 43, number of appendices - 1

This paper presents the failure analysis and diagnostic of a hydraulic turbine. Shortly after a maintenance revision the thrust bearing of the turbine was destroyed when the turbine was put into operation. The damaged bearing was examined and the possible causes discussed. To identify the problem that led to the failure of the thrust bearing, a comprehensive on-site measurement campaign was done. Vibrations, pressures, temperatures and operating parameters were acquired at different operating conditions of the turbine. The analysis of the data allowed to determine the source of the problem and to implement a solution. The authors would like to thank the company Endesa Generación and the XFLEX HYDRO 2020 research and innovation program under grant agreement No 857832FLEX.

One of the utilizations of a multipurpose dam that has socio-economic value during its operation iselectricity generation. The addition of a hydropower component to a PPP project is quite a challenge due to substantial uncertainty related to hydrological aspects that will impact electricity production and revenue, as well as high initial investment costs for generating units. This study aims to map the technical potential of hydropower and evaluate the economic feasibility of hydropower in the Merangin Dam PPP Project. The potential for power and energy generation is obtained through simulations of the hydropower operation for 19 years using hydrological data, HEC-HMS model generated-data, and dam engineering design. According to the results, the technical potential of hydropower can produce, on average, power of Pp = 103.8 MW during peak load, Pb = 98.53 MW during base load, and total energy of 636.66 GWh/year. The economic potential is evaluated through social cost-benefits analysis (SCBA) by estimating the additional benefits obtained from the hydropower compared to the PPP structure of the Merangin Dam without hydropower. Through SCBA, the addition of hydropower to the Merangin Dam PPP structure has an EIRR value of 35.24%, NPV of Rp. 2.104.212.122.723,- and BCR = 3.06. Based on these indicators, the provision of hydropower plants is considered economically feasible because the benefits that will be generated and obtained by the community are higher than the economic costs incurred.Keywords: Technical potential, economic feasibility, hydropower plant, multipurpose dam, PPP