Hydro Projects Research Articles

Identifying environmental impacts on planktonic algal proliferation and associated risks: a five-year observation study in Danjiangkou Reservoir, China

Understanding the risks of planktonic algal proliferation and its environmental causes is crucial for protecting water quality and controlling ecological risks. Reservoirs, due to the characteristics of slow flow rates and long hydraulic retention times, are more prone to eutrophication and algal proliferation. Chlorophyll-a (Chl-a) serves as an indicator of planktonic algal biomass. Exploring the intricate interactions and driving mechanisms between Chl-a and the water environment, and the potential risks of algal blooms, is crucial for ensuring the ecological safety of reservoirs and the health of water users. This study focused on the Danjiangkou Reservoir (DJKR), the core water source of the Middle Route of the South-to-North Water Diversion Project of China (MRSNWDPC). The multivariate statistical methods and structural equation modeling were used to explore the relationships between chlorophyll-a (Chl-a) contents and water quality factors and understand the driving mechanisms affecting Chl-a variations. The Copula function and Bayesian theory were combined to analyze the risk of changes in Chl-a concentrations at Taocha (TC) station, which is the core water source intake point of the MRSNWDPC. The results showed that the factors driving planktonic algal proliferation were spatially heterogeneous. The main factors affecting Chl-a concentrations in Dan Reservoir (DR) were water physicochemical factors (water temperature, dissolved oxygen, pH value, and turbidity) with a total contribution rate of 60.18%, whereas those in Han Reservoir (HR) were nutrient factors (total nitrogen, total phosphorus, and ammonia nitrogen) with a total contribution rate of 73.58%. In TC, the main factors were water physicochemical factors (turbidity, pH, and water temperature) and nutrient factors (total phosphorus) with total contribution rates of 39.76% and 45.78%, respectively. When Chl-a concentrations in other areas of the DJKR ranged from the minimum to the uppermost quartile, the probabilities that Chl-a concentrations at the TC station exceeded 3.4 μg/L (the benchmark value of Chl-a for lakes in the central-eastern lake area of China) owing to the influence of these areas were all less than 10%. Thus, the risk of planktonic algal proliferation at the MRSNWDPC intake point is low. This study developed an integrated framework to investigate spatiotemporal changes in algal proliferation and their driving factors in reservoirs, which can be used to support water quality management in mega hydro projects.

Analysing just energy transition practices in India, Nepal and Bhutan using a trilogy framework of decarbonisation, decentralisation democratisation

The paper discusses the trilogy framework of decarbonisation, decentralisation and democratisation and its relevance in the implementation of just energy transition agendas in rural communities of Global South countries (GSCs). It argues that just energy transition should be implemented via developing nationally independent but locally driven renewable energy projects in GSCs. To corroborate the trilogy framework, the paper discusses case studies of India’s Panchayat institutions, Nepal’s community renewable projects, and Bhutan’s hydro projects. The paper recommends that the trilogy framework be implemented in GSCs through the concept of ‘energy prosumer communities’.

Computational investigation and optimization of the bulb turbine for ultra-low head application

The Indian River, which is celebrated for its breathtaking beauty and diverse heritage of cultures, has an extensive amount of potential for producing green hydroelectric electricity. 7.5 % of the world's energy came from renewable sources in 2022, with India making up 36 % of the share and growing. India has nearly reached the 5 GW objective for small hydro projects and has reached 68 % of its 175 GW renewable energy ambition. At 90 % efficiency, bulb turbines are hydroelectric turbines that produce power from water, making them a perfect choice for high flow rates and low water head conditions. In order to optimize bulb turbines, this research investigates the use of computational fluid dynamics (CFD) to assess variables including the number of guiding vanes, the angle of the draft tube, and the design of the blades. According to studies, efficiency is increased when guiding vanes increase. The geometry of guiding vanes also has a significant impact on performance. Draft tubes, which restore kinetic energy from water entering the turbine, can enhance efficiency with proper design. Adding anti-cavitation capabilities to runner blades improves performance even further. CFD models verify these conclusions, with little variations from the field data. By fine-tuning important parameters such as 14 guiding vanes and adjusting the draft tube angle to 2.5°, the turbine's efficiency jumped from 87 % to 97 %.

REVIEW OF STRUCREVIEW OF STRUCTURAL DEVELOPMENT OF DAMS WITH AN EMPHASIS ON THE CONSTRUCTION OF THREE GORGES DAMTURAL DEVELOPMENT OF DAMS WITH AN EMPHASIS ON THE CONSTRUCTION OF THREE GORGES DAM

<p>Dams are hydrotehnic engineering structures that have undergone significant advancement throughout history from an engineering standpoint, and today they represent some of the most complex constructions. Additionally, they play a crucial role in the economic development of many countries. Four basic types of dams have been developed: embankment, gravity, buttress, and arch dams. Each of them poses unique challenges that require significant efforts from engineers, which include the constant development and application of new technologies. One of them is the Three Gorges Dam, which represents the largest gravity dam, as well as the largest hydroelectric complex in the world. The technology of the project is extremely complex, and together with the comprehensive benefits to the community, makes the project more challenging than any other hydro project in the world.</p>

Empowering rural electrification in the Philippines: a case study

The paper describes the application of micro hydro power to improve the quality of life of people in rural areas. In this paper, two case studies in the Philippines are presented. One case study is a micro hydro power plant located in Parina in the north of the Philippines developed by an academic institution, De La Salle University; it utilises simple technology. In contrast to Parina, another micro hydro case study developed by a non-governmental organisation (NGO), YAMOG, is located in Timodos in the southern region of the Philippines; it implements more sophisticated technology. Even with differences in technology, similarities in terms of community dynamics, preparation, development, and impact on the community are evident in both case studies. The implementation phases for the two case studies were analysed to determine the characteristics for a successful micro hydro project in conjunction with its social impact. It is shown that micro hydro is a potential solution for clean and sustainable energy access for rural areas.

Model studies for desilting basin for Teesta-VI H.E. project, Sikkim – a case study

Desilting basins play an important role in run-of-river hydro power projects on Himalayan Rivers. These rivers carry huge amount of sediment with them, due to steep slopes and fragile geology of the region. The suspended sediment enters through the power intake and ultimately the power house. This causes heavy damage to the turbines and other under water parts. Therefore, desilting basins are provided to eliminate suspended sediment from the water conductor system. The design of desilting basin is verified on a physical model for 90% removal of suspended sediment coarser than 0.2 or 0.3 mm and efficacy of flushing tunnel below in transporting the settled sediment. Central Water and Power Research Station, Pune has conducted physical model studies for desilting basin for various hydro power projects in India and neighbouring countries. One such study, Hydraulic model studies for desilting basin for 500 MW Teesta-VI Hydro Electric Project, Sikkim is presented in this paper. Various design parameters such as length of desilting basin, length and bed slope of inlet transition, outlet transition, size of silt flushing tunnel, size and spacing of openings connecting main basin with silt flushing tunnel etc. were tested during the model studies. The results in terms of settling efficiency for 0.3 mm size particles were obtained.

Flexibility extension in hydropower for the provision of frequency control services within the European energy transition

This paper presents a comprehensive assessment of the large-scale deployment of hydropower on the provision of frequency regulation services, when equipped with the extended flexibility solutions being developed and/or tested within the scope of the XFLEX HYDRO project. The current analysis is performed on the Iberian Peninsula (IP) power grid considering its interconnection to the Continental Europe (CE) system, since this power system zone is expected to have the most severe frequency transient behaviour in future scenarios with increased shares of variable renewable energies. For this purpose, prospective scenarios with increased shares of time variable renewable generation were identified and analysed. To assess the impacts of the hydropower flexibility solutions on frequency dynamics after a major active power loss, extensive time domain simulations were performed of the power system, including reliable reduced order dynamic models for the hydropower flexibility solutions under evaluation. This research assesses the effects of synchronous and synthetic inertia, and of the Frequency Containment Reserve (FCR) and Fast Frequency Response (FFR) services as specified in European grid codes. The main findings highlight the potential of hydropower inertia and of adopting a variable speed technology for enhancing frequency stability, while contribute to better understand the role of hydropower plants in future power systems.

Feasibility Study of a Micro Hydro Power Plant for Rural Electrification in Lalumpe Village, North Sulawesi, Indonesia

This feasibility study aims to assess the potential of implementing a micro hydro system in Lalumpe Village, located in North Sulawesi, Indonesia. The study focuses on evaluating the technical and economic aspects of the proposed micro hydro project. Data collection was carried out through field surveys, interviews with local stakeholders, and analysis of available hydrological and topographical data. The technical assessment involved conducting a resource assessment to determine the water availability and potential for harnessing hydroelectric power in the area. The study also examined the village’s energy demand and determined the suitable capacity of the micro hydro system required to meet the community’s needs. Economic analysis included estimating the initial investment costs, operation and maintenance expenses, and potential revenue generation from the sale of excess electricity to the local grid. Financial viability indicators such as payback period and net present value were calculated to assess the economic feasibility of the project.

Perception, preference and hunting strategies of mammals in a rural community in the semi-arid region of Northeastern Brazil

The goal of this study was to characterize the hunting of mammals in a rural community in the Northeast of Brazil affected by the largest hydro project in the country. We used semi-structured questionnaires, free lists and visual stimuli to estimate the perceived abundance of species, which are prioritized for hunting, selection criteria and methods used in collection. 23 species were perceived as occurring in the region, which have potential for hunting. Of these, nine were prioritized for hunting Conepatus semistriatus, Euphractus sexcinctus and e Dasypus novemcinctus species with greater cultural prominence. The averages of perceived abundance of the species ranged from 1.1 a 3,8. Meat flavor was the main prioritization criterion at the time of hunting. Nine methods are used in hunting, which can be combined between, as well as used in more than one species. The recent scenario of environmental modification with the creation of perennial water sources may be promoting changes in the local hunting pattern. However, new research must be carried out to understand how the permanent availability of water will contribute to changes in socioecological systems in the Brazilian semi-arid region.

The Materiality of Space: Infrastructuring the Border Space in Arunachal Pradesh

The materiality of space refers to the material constituents determining the space. The spatial imagination of the borderland, characterised by critical spatiality, is materially constituted. The fact of being materially constituted means to be infrastructurally configured. The infrastructures here include hydro projects, highways, railroads, bridges, tunnels, airports, digital connectivity and other defence-related installations. These projects combine a two-pronged approach: security and development. The security challenges that the border space embodies compel the state to adopt an approach of competitive infrastructure building. The nature of this competition is determined by the competing other’s approach towards the border space. Arunachal Pradesh is a very critical border state that shares its crucial border space of 1,080 km with China, 160 km with Bhutan and 440 km with Myanmar. China’s increasing geopolitical clout in the region intensifies its spatial and material prominence. India under its Act East Policy (AEP) formulation in 2014 has taken up a very determined approach to accelerating infrastructure growth in the northeast and more particularly in Arunachal Pradesh for its border spatiality. Therefore, the border space loses its inferential, conjectural and abstract character and becomes materially determined. This imperative for materiality embodies, on the one hand, development, modernity, capitalist social space and mainstreaming of the neglected and, on the other hand, protectionism and upgradation of security architecture along critical geography known as the border space. Therefore, this study examines the development of materiality, meaning infrastructure, in a complex border space like Arunachal Pradesh. It decodes the economic logic of the systematic development of border space by the Indian nation-state from the point of view of the growth of the region and security urgency. It uses Henri Lefebvre’s theoretical formulations of spatiality to understand the convoluted category of border space and the introduction of material forces to achieve security and developmental objectives.

Empirical analysis of Chinese overseas power plant investments: Likelihood of suspensions and associated environmental risks

Power sector investment is crucial to accelerate a sustainable energy transition, but not all investments are successful. We examine 1,393 Chinese overseas electric power projects across 78 countries over the past two decades. We identify 5% that have been canceled or delayed, with coal and hydro projects having much higher suspension rates than solar and wind projects. We find electric projects with higher environmental risks are more likely to be suspended. Specifically, coal projects located in more densely populated areas where more people are exposed to air pollutants, in countries with more fatalities from extreme weather events, and in places with a record of environmental protests, are more likely to be suspended. Additionally, hydro projects closer to protected areas have a higher suspension rate. Our results suggest that refraining from investing in environmentally risky projects helps mitigate environmental damages and prevents financial losses due to cancellation and postponement.

Power Plant Transients including Hydraulic Short Circuit Operation Mode

Within the XFLEX HYDRO project, the possibility of increasing the flexibility of hydro power plants to support the Electric Power System (EPS) is investigated. The flexibility of the pumped-storage power plant Frades 2, as the target, should increase by extending the operating range for each unit and by using the hydraulic short circuit (HSC) operation mode. Transient investigations of the additional plant conditions are performed to ensure the safety of the plant. With a 1D model of the entire hydro power plant including both pump-turbines, valves, surge tanks, and the water-bearing components, extensive calculations are carried out to verify the safety of the existing plant for extended operation conditions. In particular, the study focuses on the synchronous and asynchronous emergency shutdowns of the plant in the new operating conditions as well as other operation-related power plant transients regarding the HSC mode. With the results presented in this paper, the flexibility of the plant Frades 2 can be increased. Delayed emergency shutdowns are identified as particularly critical during the study and should always be given additional consideration in transient investigations.

IoT, machine learning and photogrammetry in small hydropower towards energy and digital transition: potential energy and viability analyses

This research aims to evaluate and put into practise the design of a small hydropower plant on a stream at São Vicente, in Madeira Island, supported by internet of things (IoT). The photogrammetry technique is also used with a comprehensive digital transformation, in which new concepts, methods and models, such as machine learning (ML), and big data analytics play an important role due to the huge availability time series that have to be exploited in hydropower design studies. Nowadays, digitalization and massive data availability are imposing new ways to address many of the current challenges associated with the energy and digital transition. This research is based on a simple small hydropower design, to present an integrated methodology using new methods assigned by an internet protocol system, which includes the development of different steps and components supported by GIS, photogrammetry and the use of advanced tools, with the support of a drone survey with internet communication (IoT) that allow the generation of experimentally-based estimates in situ characterization, the volumetric flow, the hydrological data treatment, the hydraulic calculations and economic estimations for a real hydro project. Therefore, hydrological variables, hydraulic analysis and topographical survey are carried out in the IoT application platform supported by new tools and methods to optimise the size of hydraulic structures, estimate the performance and potential of the hydropower plant towards the best solution for energy and digital transition. Firstly, the data-base for the all study and posterior sizing of the case study of hydropower plant are defined and then the corresponding analyses and results are presented. Then, the cost estimation for the construction, maintenance and operation of the selected elements that compose the hydropower topology are determined, as well as the respective economic balance, considering the annual energy production. In addition, both economic and environmental return on investment is discussed. Finally, an analysis to equate the cost estimates and the respective benefits of hydropower generation using this new approach applicability is stablished, taking into account some economic indicators to determine the profitability of the project.

Design of Cost-Effective Microcontroller Based Load Controller with Data Logging for Standalone Electric Plant

Maintaining the voltage and frequency fluctuation using a hydraulic governor in Standalone Micro- Hydro Projects (SMHEP) is costlier than the generator itself. So, an Electronics Load Controller (ELC) is used to regulate output power of generator used in the SMHEP. Developments in the ELCs will play an important role in increasing the efficiency and life span of the power plant thereby providing a lot of space for the further improvements. This paper analyzes the current trends and tries to identify their limitations and suggest a novel approach in designing a cost effective ELC system with the capabilities of data logging. In this study software simulation was carried out in Proteus, while the experimental model was designed using microcontroller and integrated sensor system. Both the software and hardware implementations showed positive results. The experiment was carried out under laboratory conditions in which the proposed model successfully diverted the excess power to connected dump loads and allowed the generator to generate the power at full load with efficient data logging and graphical user interface. Keyword: Data Acquisition, Electronic Ballasts, Load Management, Sensor Systems and Applications, Standalone Power Supply

A framework to assess multi-hazard physical climate risk for power generation projects from publicly-accessible sources

Demand for information about physical climate risk is growing, particularly for the power generation sector, given its size and pronounced exposure to climate hazards. However, quantifying physical climate risks for a large number of assets remains challenging. Here we introduce a scalable and transparent methodology that enables multi-hazard physical climate risk assessments for any thermal or hydro power generation project. The methodology relies on basic power plant type and geolocation data inputs, publicly-available climate datasets, and hazard- and technology-specific vulnerability factors, to translate hazard severity into generation losses. We apply the methodology to the European Bank for Reconstruction and Development’s early 2021 thermal and hydro power generation portfolios of 80 assets. We show that under the Representative Concentration Pathway 4.5 scenario, those 80 power plants could experience a 4.0-10.9 TWh loss in annual generation (or 1.87-5.07% of total annual maximum generation) by 2030 compared to its baseline losses of 0.70–0.87 TWh (or 0.33–0.41%). One of the largest drivers of the increased risk is rising water temperatures, which is currently overlooked by mainstream climate risk disclosure guidelines.

Analysis of Bhutan's energy policies in relation to energy security and climate change: Policy perspective

Energy security is at the heart of the energy policy. Achieving energy security, however, is difficult as energy sector faces challenges due to resource depletion and climate change. It is becoming a key concern for Bhutan due to perpetual demand growth including climate change presenting formidable challenge. These developments, particularly climate change impact on renewable resources, hydropower, which is the backbone of Bhutan's energy sector, faces vulnerability issue. Given these emerging challenges, this paper presents preliminary analysis of Bhutan's energy policies from energy security perspective in the face of climate change. In doing so, key energy policies encompassing all mainstream fuels: renewable, coal, oil, and gas, were reviewed. Energy security aspect is sparingly addressed in renewable energy policies. There are no policies related to mainstream fossil fuels from energy dimension. However, import of fossil fuels have increased exposing to price volatility, prompting affordability concerns. The energy policies lack integration of climate factor given the increased emission from fossil fuels and development of hydro projects in highly vulnerable river basin. There is dearth of an integrated energy policy as existing policies are disintegrated, and specific to each fuel, and therefore lacks coordination and synergy.

Towards accurate vibration prediction of pump-turbine runners in deep partial load operation

Within the XFLEX HYDRO project, operating power plants in low load conditions is being investigated as one of the possibilities to enhance the flexibility of hydropower. Therefore, the structural dynamic behaviour of a pump-turbine runner is numerically analysed in deep partial load (DPL) operating points. Based on highly resolved unsteady CFD simulations performed prior to this work, the pressure fluctuations are extracted and mapped onto the structure for subsequent Finite Element (FE) analyses. Herein, an efficient hybrid methodology combining purely structural and coupled Fluid-Structure-Interaction (FSI) modelling is applied. The obtained simulation results are compared to experimental measurements. Herein, the influence of several factors such as the CFD mesh size, the turbulence model, the simulated time window width, and the structural simulation type is studied. As a result, the numerical outcome is validated with good accuracy. The importance of highly resolved CFD simulations with appropriate turbulence modelling is highlighted. Besides, the necessity of coupled acoustic-structural analyses to accurately resolve the dynamic response to excitation by rotor stator interaction (RSI) pressure shapes is demonstrated despite the chaotically dominated nature of the structural vibrations. The results of this work can be used to extend the operating range of the pump-turbine runner and, most importantly, to calibrate numerical models to predict the structural vibrations accurately and efficiently in DPL and finally ensure safe operation of these components.

Numerical investigation of the structural behaviour of a headwater bifurcation in hydraulic short circuit

Within the XFLEX HYDRO project, hydraulic short circuit operation (HSC) is being investigated as one of the possibilities to enhance the flexibility of pumped storage powerplants. Therefore, the structural behaviour of a headwater piping bifurcation of a pumped-storage power plant is investigated. Based on unsteady CFD simulations, time history mechanical simulations are carried out to assess the dynamic integrity of the structure in pump (PP), turbine (TT) and hydraulic short circuit operation. Since the plant at hand was initially designed for PP and TT operation, simulating these load conditions delivers a base of assessment for the admissibility of HSC loading. Herein, the focus of the assessment lays on the welded joints. First, a modal analysis of the rock-supported structure is conducted to identify the required numerical analysis method to be employed for the time-history structural simulations. The CFD pressure fluctuations are then applied to the structure within time history FE analyses. The dynamic structural simulations deliver low stress fluctuations which go hand in hand with the low pressure fluctuations previously determined using CFD. Besides, the structure exhibits comparable stress oscillations for all three loading conditions. The latter stress oscillations lie below the fatigue limit of the welds. The study herewith presents promising findings towards safe HSC operation ensuring more flexibility of the power plant at hand.

Assessing Potential of Dor River as Small Hydro Project for Lessening Energy Crisis and Enhancing Tarbela Reservoir Life in Khyber Pakhtunkhwa, Pakistan

This study was conducted to design a small hydropower project at Dor River in Abbottabad, Khyber Pakhtunkhwa, Pakistan. The study area is part of the Hazara Basin and contains sedimentary rocks deposited in glaciofluvial, fluvial and marine environments. The suitable locations were chosen for the proposed hydropower project components and shown on geological map of the study area. Rock Mass Rating (RMR) studies were conducted to check the quality of rocks exposed at the selected sites. The rocks were classified as fair rocks with RMR ranging from 48 to 55, which shows that rocks are suitable for construction activities, e.g., tunneling, etc. The rocks of the area were also found suitable for their use as a construction material, which is an additional positive aspect of this study. For potential hydropower evaluation, the discharge of the Dor river was measured using the current meter method. Additionally, the sediment load of the river was determined using Whatman filter papers. The Dor River water discharge is variable, where the maximum water discharge was found in the months of July (6.79 m3 s−1) and August (6.71 m3 s−1). Hence, the construction of a small hydropower project on Dor River can be favorably undertaken to produce a plant with low (2.79 MW), average (5.37 MW) and high-power potential (13.16 MW). In suspended sediment load analysis, it was found highest in the months of July and August and lowest in December. Annually, the Dor River takes 7267 tons of sediment to Tarbela Reservoir, which is likely to adversely affect both the life and capacity of the country’s currently largest hydropower-producing reservoir located downstream. The construction of the hydropower project proposed in this study will effectively slow the deposition of sediment into Tarbela Reservoir, which in turn will enhance the life of the reservoir positively.

EXPERIMENTAL AND CFD SIMULATION VALIDATION PERFORMANCE ANALYSIS OF FRANCIS TURBINE

Francis Turbines are designed to Extract hydraulic power as much as possible in hydro power plant stations. Performance analysis and selecting design of hydraulic turbines are two very essential aspects of any hydro power project which ensure the economical and efficient functioning of these hydro power plants.CFD simulation can provide us insight into field flow characteristics which will help us understand the design parameter and development of Francis turbine. The performance analyzed in different operating conditions with the help of numerical simulation and experimental testing. The various visualization techniques in numerically and Physically model testing for hydraulic performance with maximum-minimum and rated head and different flow rate analyses of the turbines are briefly discussed. These techniques can be provided efficiency and insight flow characteristics with different operating conditions of the Francis turbine. Efficiency is calculated 94% with Computational fluid dynamics simulation with an error of less than 0.7% compared with physical model testing. The numerically simulation and physical model testing are shown that feasibility for the optimal design of the hydraulic Francis turbine.