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That there is an imbalance of electricity demand and supply in Ethiopia is known. Development of the Micro hydro power (MHP) system is an important technology to solve the problem. The main objective of this study was to do modelling and simulation of a micro-hydropower system for rural electrification in the case of Temecha River, Ethiopia. Yearly flow data were collected from Ethiopian Basins Development Authority and used to estimate the design flow rate. Next, modelling and simulation were done by using MATLAB SIMULINK. Some of the SIMULINK results were power and flow duration curves, and others. The nethead and design flow rates were found to be16.34m and 0.5731m3/s, respectively. Based on the preliminary analysis, the turbine selected for the site is a Kaplan turbine. It is found that, the power output of this system is greater than the electricity demand of the selected site for 346 days of the year. Thus, the systemic found to be efficient in terms of generated electrical power as compared to similar works reported in the literature. The scale of the design can be re modified to be implemented in other remote are as having river resources. Key words: electrical power, flow rate, Kaplan turbine, MATLAB SIMULINK, MHP, simulation, Zede Journal of Ethiopian Engineers and Architects, Vol. 41 (2023): Zede Journal of Ethiopian Engineers and Architects

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.

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.

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.

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.

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.

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.

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€.

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.

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

This study evaluates the impact of future climate change (CC) on the hydropower generation potential of the Bamboi catchment (Black Volta) in West Africa using a conceptual rainfall-runoff model (HBV light) and regional climate models (RCMs)–global climate models (GCMs). Two climate simulation datasets MPI-ESM-REMO (CORDEX) and GFDL-ESM2M-WRF (WASCAL) under RCP4.5 were applied to the validated hydrological model to simulate the catchment runoff. Based on reference and future simulated discharges, a theoretical 1.3 MW run of river hydro power plant was designed to evaluate the hydropower generation. Hydrological and hydropower generation changes were expressed as the relative difference between two future periods (2020–2049 and 2070–2099) and a reference period (1983–2005). The climate models' ensemble projected a mean annual precipitation increase by 8.8 % and 7.3 % and discharge increase by 11.4 % and 9.735 % for the 2020–2049 and 2070–2099 periods respectively (for bias corrected data). On the contrary an overall decrease of hydropower generation by −9.1 % and −8.4% for the 2020–2049 and 2070–2099 periods was projected respectively. The results indicate that projected increases in discharge should not solely be considered as leading to an increase in hydropower potential when prospecting climate change impact on hydropower.

Water resources/reservoir management in developing countries attracts considerable attention due to growing human requirements and environmental concerns. The Seimare–Karkheh hydropower reservoir cascade, in the Karkheh River basin southwest of Iran, was studied. The impacts of changing reservoir operating water levels on hydropower generation and downstream environmental requirements were evaluated under different climate change conditions. For several years, the operating water level of Seimare reservoir was 704.5–720.0 metres above sea level (masl) (H1). Decision makers then adopted a different policy, with the operating range changed to 704.5–723.0 masl (H2). More recently, decision makers reduced the normal and minimum water levels so the reservoir now operates at 695.0–704.5 masl (H3). It was found that, for the period 2006–2050, based on H3, hydropower production would be reduced by 2.3–12.1% and 2.4–12.6% compared with policies H1 and H2, respectively. In 2051–2100, these reductions were found to be 5.8–11.2% and 7.7–11.3%, respectively. Furthermore, the results demonstrated that the current policy would substantially affect downstream hydrological alteration: 60–72% in Seimare River and 48–66% in Karkheh River for the period 2006–2050. The issue was found to be more pronounced in 2051–2100, with hydrological alteration of 68–73% in Seimare River and 59–66% in Karkheh River.

Indian hilly areas are blessed with a lot of potentials of renewable energy sources, yet their residents are facing the problem of power unavailability. This makes their life even more difficult in these isolated areas and creates a hindrance in their holistic development. In this paper, an optimized solar photo voltaic (SPV)/wind energy conversion(WEC)/biogas generator (BGG)/biomass generator (BMG)/micro hydropower system (MHPS)/battery based integrated renewable energy model(IREM) is suggested for satisfying the energy need of different load sectors of the Mori Block, Uttarakashi district, Uttarakhand State, India. An extensive investigation has been done for accessing the demand and potential of locally available renewable energy sources. Genetic Algorithm (GA) technique has been utilized for optimizing various energy cost and emission parameters such as; cost of energy (CE), cost of generation (CG), cost of total energy (COTE), and CO2 emission. The suggested energy model is not only ensures the availability of reliable and economic power supply but also significantly limits the environmental degradation caused by the diesel generator operation in terms of CO2 emission. Further, the suggested optimization technique is also compared with other techniques for establishing its effectiveness in the field of isolated hilly areas electrification and holistic development.

In the last few decades, the energy demand is increasing globally which, given the present dependency of the energy generation on fossil fuels, results in a continuous increase in CO2 emissions. In an isolated electric grid system like in the SIDS, the majority of the electricity is produced by fossil fuels, therefore most of the SIDS nations are now focusing on Variable Renewable Energy sources (VREs). VREs such as wind and solar are hardly predictable and bring instabilities in the electric power system if not buffered by a storage system. Here we investigate the possibility of using Seawater Pump Storage Hydropower Systems (S-PSHS) as a renewable energy storage solution in an isolated electric grid. For this, the island of Curacao (one of the SIDS nations) is used as proof of the concept. For detecting potential locations for the S-PSHS sites on the island, GIS application was developed. The application of this conceptual proposed solution in similar systems is straightforward and it can be easily upscaled in other geographies. The concept of using seawater for the pumped hydro project is not common in practice and it is anticipated to have technical, environmental and financial challenges which are discussed in this paper.

Industrial development, increased demand for energy, limited fossil fuels, and the prevention of environmental damage have led to the use of renewable energy to produce power. The combined system includes renewable wind and solar energy systems or other renewable energy. The hybrid system has been widely used in recent decades to provide energy. In this research, an optimal integrated system has been used to generate electricity. The proposed system includes wind, hydropower, and photovoltaic systems. to estimate the maximum power generation and reduce fluctuations in electricity generation, three proposed algorithms have been used and three common solutions have been applied to solve the optimization problem. The performance of the combined system in different weather conditions has also been assessed. The results showed that among the three proposed algorithms, the model improved the Barnacles Mating Optimizer Algorithm (IBMO) has the best distribution and convergence. Among the three common solutions, a common solution has the most logical solution to the optimization problem. And among the different hydrological conditions, the highest electricity generation is related to the wet season. the most important role in the hybrid system related the hydropower so that despite the reduction of electricity produced in the wind and photovoltaic power plants, the hydropower plant compensates for the drop in production of these systems and causes the production flow to continue.

Nowadays, special attention is paid to hydroelectric production because it is an efficient, reliable, and renewable source of energy, especially in developing countries like Cameroon, where hydropower potential is the main source of electricity production. It also represents a useful tool to reduce the atmospheric greenhouse gas concentrations caused by human activities. However, it is the most sensitive industry to global warming, mainly because climate change will directly affect the quality, quantity of water resources (streamflow and runoff), which are the important drivers of hydropower potential. This study examined the response of hydropower potential to climate change on the Lagdo dam located in the Benue River Basin, Northern Cameroon. Hydropower potential was computed based on streamflow simulated using HBV-Light hydrological model with dynamically downscaled temperature and precipitation from the regional climate model REMO. These data were obtained using the boundary conditions of two general circulation models (GCMs): the Europe-wide Consortium Earth System Model (EC-Earth) and the Max Planck Institute-Earth System Model (MPI-ESM) under three Representative Concentrations Pathways (RCP2.6, RCP4.5 and RCP8.5). The results suggest that, the combination of decreased precipitation and streamflow, increased PET will negatively impact the hydropower potential in the Lagdo dam under climate change scenarios, models and future periods.

In this study, an attempt is made to manage the gap between energy demand and energy supply by predicting hydropower production, energy demand, and greenhouse gas emissions. The interaction between climatic, hydrological, and socio-economic parameters creates a nonlinear and uncertain relationship. The complexity of this nonlinear relationship necessitate the use of ANN to estimate energy demand. To predict energy demand, ANN model is used along with improved Electromagnetic Field Optimization (IEFO) algorithms. The results show, hydroelectric generation in the near future under RCP2.6, RCP4.5, and RCP8.5 is decreased 10.981 MW, 12.933MW, and 14.765MW and in the far future decreased 21.922 MW, 23.649 MW, and 26.742 MW. The energy demand increases in the near future 513 MW and far future 1168 MW. According to forecasting hydropower generation and energy demand, the gap between the demand-supply will increase. Also, the greenhouse gases emissions is increase due to the increase in fossil fuel consumption.

The world’s climate has changed dramatically in recent years due to the development of the industry. Climate change can significantly affect hydropower plants. One of the negative effects of climate change is the reduction of hydropower generation. Therefore, to better management of power supply and demand, the climate change effect on hydropower plants should be examined. The main purpose of this study is the prediction of future hydropower generation (2021–2050) in terms of climate change. One of the factors sensitive to climate change in hydropower plants is the amount of input flow to the reservoir. In this study, a method has been used that can increase the accuracy of flow estimation. This innovation is the use of the ANN model under the new version of the Developed Crow Search Algorithm (DCSA). This algorithm increases the accuracy of prediction by solving optimization disadvantages such as getting stuck in the optimal location, the imbalance between exploitation and exploration at different levels The results showed that the DCSA algorithm with minimum error (MSE = 1.06) and maximum correlation (R2 = 0.88) compared to other algorithms has the best performance. The results of the prediction of climate change under RCPs scenarios showed that the average annual power generation will decrease under RCP2.6 and RCP4.5 and RCP8.5 about 10.74% and% 16.38 and 22.25% respectively. Also, the average annual power generation under scenarios RCP2.6, RCP4.5, and RCP8.5 by 2050 are 740.33 MW, 603.12 MW, and 585.77 MW, respectively.

The role of a hydropower plant surge chamber as a pressure buffer to compensate excessive pressure fluctuations as a result of load demand variations contributes to the degassing phenomenon of hydrogen sulfide (H2S). Recent data collected from the surge chamber of a hydropower plant reveals that the H2S extraction designs are not effective in controlling the H2S concentration levels especially during surge events. To manage a safe working environment in the presence of H2S requires a systematic evaluation and prediction of the influence of critical flow control conditions in relation to suction optimization and exhaust ducting location. A numerical study was carried out to analyze the flow dynamics and the subsequent response of H2S concentrations to cases involving the following flow mixing and suction scenarios: C1 - absence of suction fans, C2 - absence of fresh air supply, C3 - enhanced suction capability, C4 - reduction in the amount of fresh air supply and C5 - presence of additional ducting. The CFD model was able to provide a reliable assessment of the case scenarios as justified by the validation carried out with in-situ measurements (within 10 % of the actual measured data). The cases where the H2S presence was found to be acceptable with concentrations less than 5 ppm at the upper region of the surge chamber, are C3, C4 and C5. A major finding from the flow studies in the surge chamber is that a combination of negative pressure at the suction locations and the absence of the forced fresh air resulted in significant amount of air drawn in from the outdoors. It was also found that the existing forced fresh air inlet locations are inappropriate as they generate vortex flows which displaces the H2S adjacent to the water level upwards and would later fill the entire chamber. All in all, the validated CFD model of the hydropower plant surge chamber was helpful in providing an understanding of the flow conditions in relation to the management of H2S concentrations.

Power system operations are unavoidably influenced by forecast uncertainties. The forecast uncertainty's effect on operations was quantified in individual systems, however, was seldom investigated in a hybrid system. This study aims to quantify the effect of forecast uncertainties on the hybrid hydro–photovoltaic system operation. First, the operation model is built considering streamflow and photovoltaic forecast uncertainties with long- and short-time scales. Second, total release uncertainty is determined from the sum of squares for releases under different forecast scenarios. Finally, a variance partitioning method is used to divide the total release uncertainty into the uncertainties induced by individual forecast errors. Longyangxia hybrid hydro–photovoltaic power plant from China was selected as a case study. Results provide following insights: (1) long-term inflow forecast uncertainty accounts for 98.89% of the contribution to the long-term release uncertainty, while photovoltaic uncertainty accounts for 1.11%; (2) long-term inflow forecast uncertainty still dominates the short-term release uncertainty, with the contribution of 62.06%; and (3) the total release uncertainty decreases in long-term hybrid operation compared with the reservoir operation, indicating the complementary relationship between long-term hydropower and photovoltaic power. These implications highlight the importance of improving forecast accuracies for varied energy sources at different time scales.

Currently, households in the East Region of Cameroon (ERoC) depend solely on fossil-fueled plants to meet their energy needs. Fossil fuel-based sources are a major drain on public finance in addition to being a key contributor to the increase in carbon footprints. Alternatively, the ERoC is blessed with a hydropower potential estimated at around 620.37 MW, with a production potential of 5.36 TWh per year. However, despite its favorable candidates’ sites, hydropower resources are yet to be harnessed in the ERoC. Hence, the need for a thorough assessment of hydropower potential is necessary in order to increase stakeholders’ awareness and interest in attractive hydropower resources. This paper evaluates and highlights the hydropower potential of seven selected locations in the ERoC and contributes to constituting a database for the stakeholders of the hydropower resources for electricity generation. Specifically, hydrological data, mean flow rates and mean volume contributions on each site’s river basin are explored. Furthermore, the present work highlights optimal regulation ratios, nominal flow rates, producible energy, investment costs as well as other useful parameters for projected hydropower plants for the seven selected locations in the ERoC. The results display a cumulative projected capacity of 582 MW, of which 19 MW from Zoukoumanbale, 18 MW from Colomines, 53 MW from Zoulabot, 297 MW from Nki falls, 129 MW from Yenga, 35 MW from Bangue and 124 MW from Ngoila. Moreover, 3 929 GWh are projected cumulative producible energy for the selected locations. Investment costs estimates of hydroelectric plants range between 2 964 € per kW (for Colomines) and 3 002 € per kW (for Bangue).

In the study area, due to the impact of climate change on hydropower generation and energy demand has been investigated the impact of climate change on hydropower generation, and the changes between demand and supply. To predict hydropower generation is utilized Representative Concentration Representative (RCPs) scenarios. Due to the effect of various influential factors such as climate, economy, and social on energy demand, in this study, a proposed model is used to increase the accuracy of energy demand forecasting. This model is an optimal Artificial Neural Network (ANN) model using the Developed Pathfinder Algorithm (DPA) The results of forecasting the climatic parameters showed that in the next 25 years, the temperature will increase and rainfall will decrease. Changes in hydropower generation under RCP2.6 and RCP 8.5 163.3 MW and 188.3 MW will be less than the base time. The results of the energy demand simulation showed that due to the impact of population, Gross Domestic Product (GDP), and rising temperatures, society would face an increasing trend of energy demand. However, this demand will be higher in some seasons due to the increase in the consumption of cooling devices. The electricity demand increased by about 91.42 MW compared to the base period. Examining the changes in demand and energy production, it was found that energy demand would be higher than energy production. Therefore, there is probably a shortage of energy in the future.

This paper presents renewable energy systems based on micro-hydro and solar photovoltaic for rural areas, with a case study in Yogyakarta, Indonesia. The Special Region of Yogyakarta, located on the island of Java, Indonesia, has a high potential for the development of renewable energy resources, especially hydropower and solar power. Many rural areas in Yogyakarta lack a supply of electricity. In this study, data on the potential for hydropower and solar power in rural regions of Yogyakarta are processed to determine the best capacity of hydroelectric and solar power plants. The extended particle swarm optimization (PSO) technique has been used to ensure optimal capacity optimization of this hybrid systems. The final result of this study is the most optimal of hydropower and solar power generation capacity based on the calculation of cost of capital, grid sales, cost of energy, and net present value.

This paper describes the procedure for an extensive survey of hydropower potential locations to be employed at the originating hydropower development planning stage in a basin. The approach utilized spatial tools such as Arc-Hydro, Remote Sensing (RS), and GIS to characterize the Osse Sub-basin (OSB) and Natural Resources Conservation Service - Curve Number (NRCS-CN) hydrological model to compute the stream Peak discharge Qp. This method permits identification of Small Hydropower (SHP) potential locations by considering obtained catchment parameters along the drainage network in a run-of-river project that satisfies the requirement of establishing hydropower plants, which is difficult to achieve in traditional survey study. Results indicate 18 out of 148 points examined in OSB can produce between 677.485 kW and 7622.877 kW clean energy at 92% flow exceedance annually, preventing between 555.8 and 6543.0 tCO2/yr emission from polluting the environment if developed against GHG emission sources. The calculated project cost range is £ 937,167.48–4,048,733.99. This study establishes first clean development mechanism (CDM) procedure in Nigeria to help future activation of SHP resources by identifying SHP promising project sites that can earn saleable certified emission reduction (CER) credits in the optimization model named SHP Resource Assessment and Sustainability Analysis (SHPRASA).

204 persons were killed while two hydropower projects located in close proximity at Rishiganga (13.2 MW), and Tapoban (520 MW) were damaged in Dhauliganga flood of February 7, 2021 in the Indian Himalaya. This incidence occurred during the winter season when the discharge of the glacier fed rivers is minimal, and no rain was experienced in the region around the time of the flood. Despite discharge of the main river, Rishiganga, not involved in the flood due to damming upstream of its confluence with Raunthi Gadhera, based on field evidences massive volume of around 6 million cu m water involved in this flood is attributed to sequential intermittent damming at three different places; (i) Raunthi Gadhera was dammed first in its upper reaches, (ii) Rishiganga river was then dammed to the north of Murunna, and (iii) finally Dhauliganga river was dammed around Rini village to the upstream of its confluence with Rishiganga river. Lacking warning system only enhanced the flood-induced devastation. Legally binding disaster risk assessment regime, together with robust warning generation, and dissemination infrastructure are therefore recommended for all major infrastructure projects.

There is a common misconception that at least 95% of Egypt’s potential hydropower has already been used, which does not reflect reality. Currently, only five hydropower plants operate along the river Nile, from Aswan high dam to Assiut barrage. The total installed capacity is around 2840 MW. However, Egypt has many main canals and Rayahat and an irrigation network system, including barrages, head regulators, and navigation locks, which enable 120 MW of clean electricity (equivalent to 4 times of Assiut power station generation) if used to generate electricity. This paper aims to assess mini and micro hydropower’s potential in Egypt for the main grid areas. Eight sites have been selected and ranked as an application sample in this work based on their hydraulic data availability. The rank of the most suitable energy generation sites is determined with spatial maps’ aid based on the flow duration curves, capacity factor, and multi-criteria analysis. The decision matrix developed to rank the selected locations, and the turbine efficiency curve is proposed in terms of the available flow to decide the suitable turbines. Also, the spatial maps give a clear vision to decision-makers of the possibility of exploiting different resources and the priority of implementation. The results obtained show a promising prospect of mini and micro hydropower in Egypt. The annual energy from the eight studied sites is estimated by 200 GWh according to the daily hydraulic data of the year 2017. Damietta barrage takes priority as the weight value of criteria is the highest value by 2.85, and its annual energy is estimated by 78.5 GWh. The eight sites are more suitable for peak load plants, but Damietta and Zefta are appropriate by less priority for baseload plants.

This paper provides a comprehensive yet concise overview of the potential, deployment, outlook, and barriers to renewable energy including small-scale hydropower, solar, wind, geothermal and bioenergy for the five Central Asian countries of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan. Small-scale hydropower potential estimates range from 275 MW to 30,000 MW, solar PV from 195,000 MW to 3,760,000 MW, wind from 1500 MW to 354,000 MW, geothermal from 2 MW to 54,000 MW, and bioenergy from 200 MW to 800 MW. However, deployment is minuscule: 5–225 MW in small-scale hydropower across five countries, whereas only Kazakhstan deployed large-scale solar PV (>800 MW) and wind (>300 MW). Though there are strategies and programs to increase deployment, with Kazakhstan in the lead, other countries lag behind in their efforts. A number of barriers hinder the development of renewable energy in the region, including issues with regulatory framework, infrastructure, finances, expertise, awareness and support, and data and information. Because these obstacles are interrelated, a cross-sector and integrated approach is necessary to overcome them. Renewable energy can help Central Asian countries satisfy a growing energy demand and avoid the negative environmental impacts of using fossil fuels.

Reliable and accurate streamflow simulation has a vital role in water resource development, mainly in agriculture, environment, domestic water supply, hydropower generation, flood control, and early warning systems. In this context, these days, deep learning algorithms have got enormous attention due to their high-performance simulation capacity. In this study, we compared multilayer perceptron (MLP), long short-term memory (LSTM), and gated recurrent unit (GRU) with the proposed new hybrid models, including CNN-LSTM and CNN-GRU. Hence, we can simulate one-step daily streamflow in different agroclimatic conditions, rolling time windows, and a range of variable input combinations. The analysis used daily multivariate and multisite time series data collected from Awash River Basin (Borkena watershed: Ethiopia) and Tiber River Basin (Upper Tiber River Basin: Italy) stations. The datasets were subjected to rigorous quality control processes. Consequently, it rolled to a different time lag to remove noise in the time series and further split into training and testing datasets using a ratio of 80 : 20, respectively. Finally, the results showed that integrating the GRU layer with the convolutional layer and using monthly rolled average daily input time series could substantially improve the simulation of streamflow time series.

In order to effectively respond to the global climate change and energy crisis, the structural transformation of energy has become an irreversible trend in the future development of China’s energy system. As a new kind of clean and renewable energy source, wind power technology has made great progress in recent years and has become relatively mature. The penetration rate of wind power in China’s power system increases continuously, playing an important role in promoting energy saving and emission reduction. However, because of their instability in time and space, wind power and solar power may pose great challenges to the safety of the power grid. To ensure power supply, thermal power generating units, combined with pumped-storage power stations, are still mainly used for peak load regulation nowadays, which is inconsistent with the long-term goal of carbon neutrality. This essay mainly studies the feasibility of turning hydropower stations into power regulation centers, taking the Three Gorges Project as the analysis object.

The topic of this paper is the recovery of energy from urban waters, which can be performed in water distribution networks (WDNs) through hydraulically and electrically regulated pumps operating as...

Rapid urbanization throughout the globe increases demand for fresh water and the ecosystem services associated with it. This need is conventionally met through the construction of infrastructure. Natural infrastructure solutions have increased to provide freshwater ecosystem services, but little global research has examined the intricate relationships between built and natural infrastructure for providing freshwater ecosystem services to cities across the globe. Using network analysis, here we examine the interrelationships between built and natural infrastructure in 2,113 watersheds for 317 cities worldwide, focusing on four key freshwater ecosystem services: freshwater provision, sediment regulation, flood mitigation and hydropower production. Our results indicate that protected wetlands contribute to sustaining freshwater provision to cities. Forest cover in protected areas can improve the capacity of large dams in reducing sediment loads and producing hydropower, but cities mainly depend on reduced impervious surfaces and more green spaces within urban areas for flood mitigation. Improved understandings of the role of natural infrastructure in urban water networks must underpin strategic decision-making to sustainably provide freshwater ecosystem services to global cities. Ecosystems that provide fresh water for cities also impact sediment flows, flood mitigation and hydropower provision. This Article looks at over 300 cities globally to gauge the interactions of natural ecosystems with built infrastructure.

Water supply pipelines and canals may possess a bulky amount of excess hydro energy. The renewable and clean feature of hydropower production with the lower cost, with shorter time of construction, and with contribution of small private sectors for investment on local projects are of major concerns. However, high expenses associated with the use of turbines in small hydropower plants have encouraged the water industry toward the use of pump as turbine (PAT). The main problem is that the pumps manufacturers do not supply the characteristics curves for using pumps in PAT mode. There is a great need for predicting the performance of PATs. The main aim of the present study was to investigate the performance of a single-stage and a multi-stage pump in turbine operating mode. An intensive field study was carried out, and the performance of the PATs was formulated and compared with the relationships presented by the preceding studies. The results indicated that the multi-stage pumps exhibit a low efficiency in turbine mode, mainly due to the high rate of leakage and non-uniform pressure distribution over the blades. Alternatively, the single-stage pumps in series operation are more effective. The top-point efficiency of PATs is higher than that of pumping mode; hence, the maximum efficiency of PATs is achieved for higher discharges and pressures. The results indicate that the existing experimental relationships are not yet capable of predicting a precise performance of different PATs. Therefore, manufacturers are to provide users with the characteristic curves of those pumps that are capable of being operating as turbines.

Reservoir sedimentation is a long-term process with various risks, such as reduction of storage capacity, hydropower generation and flood control functions throughout a reservoir's lifespan. For reservoirs facing loss of function with severe deposition, sediment flushing is an approach to preserving long-term storage. Here, submerged vanes combined with pressure flushing operations are proposed to facilitate scouring of such deposition. Experiments with various submerged vane heights, inclination angles on the flow direction, spacing, and divergent and convergent arrangements were conducted to investigate the scour cone volume and removal efficiency. Results showed that two divergent submerged vanes at an angle of 20° on the flow direction and optimum vane spacing ratios removed the deposited sediment significantly. In the presence of the submerged vanes, final sediment flushing volume and efficiency increased by a factor of 48 compared to the reference test. Using the experimental results, three equations were proposed to estimate the scour cone dimensions (length, width and depth). Additionally, a non-dimensional equation was developed for estimating the scour cone volume, using a polynomial correlation with vane spacing. The results of this study recommend the best installation of submerged vanes for releasing deposited sediments in the region near the bottom outlets of reservoirs.

Tajikistan and Kyrgyzstan are the two countries in Central Asia that have a huge reserve of hydro resources of the region. It is important to recognize the significance of the part played by the micro-hydropower plants (HPP) in the electric power generation in Tajikistan and Kyrgyzstan from the point of view of sustainable economic development. After all, the construction of micro-HPPs in mountainous areas will reliably ensure the development of small and medium-sized enterprises in the field of agriculture and livestock, industry, tourism, improve the social conditions of the population, as well as ensure the production of “green” hydrogen, which will contribute to the development of an environmentally friendly transport system in the regions. Micro HPPs gained recognition as a good alternative to traditional power generation for many developing countries around the world. This study presents a structural model and methodology of choice of a feasible type of micro HPP using the developed algorithm for calculation of hydro turbines’ characteristics based on the hydrological characteristics of small and shallow watercourses located in Central Asian countries, such as Kyrgyzstan and Tajikistan. Based on this model, the software “Calculation and choosing the type of hydro turbines for micro HPPs” has been developed. Depending on the load, a consumer can choose one of the suggested types of micro-hydroelectric power plants to meet his requirements. When choosing the type of micro-hydroelectric power station, a consumer should also take into account the factor of the seasonality of the water level, the constancy and speed of the water, and the volume of river water, since in some places the water freezes in winter.

The article presents the research results of the hydropower potential of the Vovcha River in the site of Gavrilivka Reservoir for construction of a small hydropower plant. During the research, statistical methods were used to analyze the homogeneity of long-term fluctuations of river flow. Estimation of parameters of analytical distribution curves (average long-term value Q, coefficient of variation СV, ratio of asymmetry coefficient to variation coefficient CS/CV) was performed by the maximum likelihood method. Determination of the estimated annual distribution of the flow in the site is carried out by the real year method. Methods for calculating the hydropower potential are based on the results of hydrological investigation. To achieve stated objective, the following tasks are solved: 1) the water resources of the Vovcha River in the Gavrilivka Reservoir were quantified; 2) the hydropower potential of the Gavrilivka Reservoir is estimated according to model years; 3) the value of technically achievable, guaranteed and ecologically justified hydropower potential is established; 4) technical and economic indicators of project practicability are assessed. The provision of HPP capacity has been determined both for the whole series of observations and for the distinctive model years. In particular, the provision capacity of N = 50 kW will amount on average 57% (208 days per year), and for the guaranteed component of N = 44 kW it will amount 62% (226 days per year). According to the research results, it is established that the optimal capacity of the hydropower plant is 50÷75 kW with a designed capacity utilization of 80÷70%, respectively. The approximate payback period will be 7-9 years with a 10% amortization rate, and accordingly a possible replacement of equipment in 10 years.

Nowadays, the exploitation of renewable hydropower energy sources promotes the research about water wheel as a significant source of hydropower. However, the performance characteristics of floating...

Slope eco-restoration has always received extensive attention as a positive way to reverse ecosystem deterioration derived from human interventions. A simplified framework is proposed to undertake a quantitative evaluation of the engineering disturbed slope eco-restoration success in the alpine region, southeast Qinghai-Tibet Plateau. The Dagu hydropower project that disturbs the local ecosystem to some certain was selected as the study area. Since August 2018, six types of slope (soil, rock, soil-rock, spoil, construction site, hardened) were served as the demonstration test for the slope eco-restoration with two years monitoring in the study area. Meanwhile, the topography, erosion, soil quality, and vegetation were selected as assessment indicators of the methodology. Finally, combined with the weighting method and the expert panel, the slope eco-restoration quality index (SERQI) was established and applied in the six slopes. The results suggested that the frost-resistant ecological substrate performed well in alpine region, and the SERQI value is in accordance with the actual monitoring level with spoil slope>soil slope>construction site slope>soil-rock slope>rock slope>hardened slope. The proposed framework could support slope eco-restoration practitioners for making a more objective and quantitative evaluation easily for the postimplementation restoration.

Congestion in power flow, voltage fluctuation occurs if electricity production and consumption are not balanced. Application of some electrical energy storage (EES) devices can control this problem. Pumped hydroelectricity storage (PHS), electro-chemical batteries, compressed air energy storage, flywheel, etc. are such EES. Considering the technical maturity level, storage time, capital cost, life cycle, potential etc., in India, PHS is found to be the best possible option with no additional fuel needs. In India, the Central Electricity Authority (CEA) has identified 63 sites where 96,524 MW PHS can be installed but at present 9 PHS with a total installed capacity of 4785.6 MW are in operation and 1205 MW is under construction [February 2021, CEA]. Therefore, India has wide scope to enhance its hydropower generation along with PHS. Generally, the lifespan of a PHS project is at least 50 years and these hydro projects help in reducing carbon footprint of Indian power sector as well as conserving scarce fossil fuels. So, in this paper, all the technical views related to PHS are discussed along with total PHS scenario of India as well as the constraints and policies are summarized.

The flow of water in the pipeline for household needs is a source of energy that can generate electrical energy through Pico hydro turbines or small-power water turbines. The experiment has been conducted on a 10 Watt Pico hydro turbine mounted on a water pipe against changes in water flow discharge. The turbine performance analysis is conducted experimentally (actual) and theoretically (ideal). The analysis results showed the greater the discharge flow, the greater the power generated by the turbine. In tests with a maximum discharge of 8.9 l/min, the actual power of 1.121 Watts, the torque of 0.005 Nm with a rotation speed of 2146.8 rpm and efficiency of 12.59%; while the ideal power is based on Euler turbine equation of 4.2 Watts and torque of 0.016 Nm. So, the maximum turbine power that can be generated is only 26.67% ideal. Efficiency turbine decreases with increased discharge; in this test, the maximum efficiency was 24.89% at 5.8 L/min flow discharge.

Infrastructure systems are one of the most important attributes of modern society. Earthquake induced damage to infrastructure not only results in economic losses, but also secondary effects caused by their loss of function. Proper understanding of seismic vulnerability of critical infrastructure is therefore essential for disaster risk reduction. The 2015 Gorkha earthquake (MW 7.8) and its aftershocks caused widespread damage to various infrastructure systems in Nepal. This study is an attempt to quantify seismic vulnerability and fragility functions of some of the most severely affected infrastructure systems, i.e., road pavements, highway bridges, irrigation systems, hydropower systems, and brick kiln chimneys. These functions are based on empirical data of loss/damage collected after the earthquake. Although there is considerable uncertainty in the estimation of ground motion intensity and limitations in the range of observed damages, the results highlight that these infrastructures are highly vulnerable to ground shaking and could experience major damage and significant losses during moderate to strong ground shaking.

In recent decades global warming has turned into an international concern. Anthropogenic Greenhouse gases (GHG) are produced through burning fossil fuel leading to an increase in the global warming effect; thus, GHG reduction contributes to mitigating climate change. Utilizing renewable energies, increasing efficiency of and capacity factor (CF) of existing power plants, and recycling waste energy in various industries are convenient solutions to improve the energy systems performance to reduce fossil fuel consumption, leading to GHG emission. So, there is a substantial need for planning and evaluating the energy systems in which various technologies are used, technically and economically. Theis study's main objectives are utilizing the capacity of renewable energies such as biomass, wind, solar, hydropower, and enhancement of CF and efficiency of the power plants in the Mazandaran region in the south of the Caspian Sea. The energy system considered for the region is modeled and analyzed by six scenarios in this paper. The results indicated that the share of renewable energies in electricity production could be increased from 5.4% to 47.7%. The results of cost analysis show that by applying the sixth scenario, which is integrated policies of increasing RER share and improvement of efficiency and capacity factor. The trends of total annual cost, CO2 emission, and fossil fuel consumption are reduced compared to the business as usual (BAU) scenario. The average cost saved by this scenario is about 220 MUSD/year. The average amount of fossil fuels and CO2 emission save are 11 TWh/year and 2.438 Mt/year between 2020 and 2030, respectively.

Ugandan rivers are being tapped as a resource for the generation of hydropower in addition to other uses. Studies on the reliability of these hydropower plants due to climate and land-use/land cover changes on the hydrology of these rivers are scanty. Therefore, this study aimed to model the impact of the changing climate and land-use/cover on hydropower reliability to aid proper planning and management. The hydropower reliability of Muzizi River catchment was determined from its past (1998–2010) and midcentury (2041–2060) discharge at 30 and 95% exceedance probability under Representative Concentration Pathways (RCPs) of 4.5 and 8.5, respectively. The past and projected hydropower were compared to determine how future climate and land-use changes will impact the discharge and hydropower reliability of Muzizi River catchment. Six LULC scenarios (deforestation, 31–20%; grassland, 19–3%; cropland, 50–77%; water bodies, 0.02–0.01%; settlement, 0.23–0.37%, and Barren land 0.055–0.046% between 2014 and 2060) and three downscaled Regional Climate Model (REMO and RCA4 for precipitation and RACMO22T for temperature from a pool of four CORDEX (Coordinated Regional Climate Downscaling Experiment) Africa RCMs) were examined. A calibrated SWAT simulation model was applied for the midcentury (2041–2060) period, and a potential change in hydropower energy in reference to mean daily flow (designflow ≥ 30% exceedance probability), firm flow (flow ≥ 95% exceedance probability), and mean annual flow was evaluated under the condition of altered runoff under RCP4.5 and RCP8.5 climate change scenarios for an average of REMO and RCA4 RCM. The future land use (2060) was projected using the MOLUSCE (Module for Land Use Change Evaluation) plugin in QGIS using CA-ANN. Three scenarios have been described in this study, including LULC change, climate change, and combined (climate and LULC change). The results suggest that there will be a significant increase in annual hydropower generation capacity (from 386.27 and 488.1 GWh to 867.82 and 862.53 GWh under RCP4.5 and RCP8.5, respectively) for the combined future effect of climate and land-use/cover changes. Energy utilities need to put in place mechanisms to effectively manage, operate, and maintain the hydropower plant amidst climate and land-use change impacts, to ensure reliability at all times. HIGHLIGHTS Innovative approaches for hydrological modeling in data-scarce scenarios.; The possibility to utilize bias-corrected reanalysis and historical discharge data to build a climate model in data-scarce scenarios.; Sheds light on the potential risks of land-use and climate change on hydropower reliability in data scarcity areas.; Informs the need to implement prudent catchment management practices and develop policies.

In situ measurements of water equivalent of snow cover (SWE) – the vertical depth of water that would be obtained if all the snow cover melted completely – are used in many applications including water management, flood forecasting, climate monitoring, and evaluation of hydrological and land surface models. The Canadian historical SWE dataset (CanSWE) combines manual and automated pan-Canadian SWE observations collected by national, provincial and territorial agencies as well as hydropower companies. Snow depth (SD) and bulk snow density (defined as the ratio of SWE to SD) are also included when available. This new dataset supersedes the previous Canadian Historical Snow Survey (CHSSD) dataset published by Brown et al. (2019), and this paper describes the efforts made to correct metadata, remove duplicate observations and quality control records. The CanSWE dataset was compiled from 15 different sources and includes SWE information for all provinces and territories that measure SWE. Data were updated to July 2020, and new historical data from the Government of Northwest Territories, Government of Newfoundland and Labrador, Saskatchewan Water Security Agency, and Hydro-Québec were included. CanSWE includes over 1 million SWE measurements from 2607 different locations across Canada over the period 1928–2020. It is publicly available at https://doi.org/10.5281/zenodo.4734371 (Vionnet et al., 2021).

During experiments, a micro-hydropower plant with a siphon water intake and an orthogonal turbine with five-bladed runners with an installed capacity of 30 kW was tested, and the characteristics of the power equipment in the available pressure and flow ranges were obtained. A series of theoretical and field studies on the use of free-flow orthogonal turbines in small hydropower was conducted, and possible layouts were considered. The results of tests of the orthogonal turbine of the experimental microhydropower plant were analyzed, and its efficiency and the operating conditions of the hydropower equipment in which cavitation occurs were determined.