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The shaft hydropower plant (SHPP) is a novel hydraulic concept for low-head hydropower sites with several environmental and operational advantages over conventional layouts. However, the first two projects implementing this concept have shown comparatively high construction costs and project risks. Therefore, further optimization is required to increase economic attractiveness and enable broader market adoption. Initial model tests recommend a square-shaped shaft inlet with a three-sided approach flow for low-loss and fish-friendly inflow conditions. Yet, this design requires significant space for structural implementation and may be unsuitable for use with multiple shafts or as an extension of non-powered dams and weirs. This research paper presents the application of a computational fluid dynamics simulation setup to evaluate the hydraulic performance of various design configurations, especially alternative design layouts with a one-sided approach flow without further physical model tests. The simulation setup is calibrated against observations including head loss and velocity measurements from the physical model tests, and its satisfactory performance enables the analysis of alternative design layouts. This study aims to derive the most significant design parameters for achieving the desired hydraulic conditions at the intake. Increasing the flow depth before the intake and enlarging the inlet area have the most significant impact, while increasing the overflow of the front gate has the least significant effect. The chosen CFD application is deemed suitable for hydraulic design optimization and provides guidance on the key parameters to focus on for tailored site-specific design development. [ABSTRACT FROM AUTHOR]

Flow rate is the basic parameter for calculating the energy capacity and investment costs of small hydropower plants. Because energy costs are directly related to energy capacity. While the energy capacity increases, the investment cost of the hydropower plant increases also. However, if the energy capacity is high, the energy production will be high and the investment cost will be amortized in a short time. In this study, small rivers in the Euphrates and Tigris Basins with previously determined hydropower capacities were selected, and the investment costs of small hydroelectric power plants to be designed on these rivers were analysed. For this analysis, 10 streams were selected from the Euphrates and Tigris Basins, and only Baskoy and Celebiyan streams have flow observation stations. The flow values of the remaining 8 streams were found by regression analysis using the basin and flow values of Baskoy and Celebiyan streams. Therefore, cost–benefit analyses were carried out separately for these flows in this study. In this study, because it includes the most effective hydrological parameters as well as many technical and economical parameters, the SMART Mini Hydro Tool Program was used. [ABSTRACT FROM AUTHOR]

Abstract Flow rate is the basic parameter for calculating the energy capacity and investment costs of small hydropower plants. Because energy costs are directly related to energy capacity. While the energy capacity increases, the investment cost of the hydropower plant increases also. However, if the energy capacity is high, the energy production will be high and the investment cost will be amortized in a short time. In this study, small rivers in the Euphrates and Tigris Basins with previously determined hydropower capacities were selected, and the investment costs of small hydroelectric power plants to be designed on these rivers were analysed. For this analysis, 10 streams were selected from the Euphrates and Tigris Basins, and only Baskoy and Celebiyan streams have flow observation stations. The flow values of the remaining 8 streams were found by regression analysis using the basin and flow values of Baskoy and Celebiyan streams. Therefore, cost–benefit analyses were carried out separately for these flows in this study. In this study, because it includes the most effective hydrological parameters as well as many technical and economical parameters, the SMART Mini Hydro Tool Program was used.

Abstract Water-scarce regions, like the Mediterranean, face worsening conditions due to climate change, intensifying pressure on key economic sectors such as hydropower. Additionally, environmental conservation policies, particularly the implementation of environmental flows, present challenges for hydropower systems. Certainty regarding the impact of these factors on future hydropower production is crucial for informed decision-making in the transition to sustainable energy. This study introduces S + HydPower, a tool coupled with SWAT+ to assess climate change and watershed management effects on small hydropower plant (SHP) systems. In this study, we used this tool to investigate the consequences of implementing environmental flows and climate change on run-of-river SHPs in the Catalan River Basin District (CRBD), in Catalonia. The results show that applying environmental flows would lead to a significant 27% reduction in SHP production. However, this reduction would represent only 0.25% of the region’s current energy demand. Furthermore, the study reveals a potential 38% to 73% reduction in SHP production by the end of the twenty-first century due to the combined effects of environmental flows and climate change. This suggests a substantial decline in run-of-river SHP’s contribution to the CRBD’s electricity supply. These findings emphasize the need to explore alternative and sustainable energy sources to ensure the long-term reliability and resilience of the region’s energy supply.

Water-scarce regions, like the Mediterranean, face worsening conditions due to climate change, intensifying pressure on key economic sectors such as hydropower. Additionally, environmental conservation policies, particularly the implementation of environmental flows, present challenges for hydropower systems. Certainty regarding the impact of these factors on future hydropower production is crucial for informed decision-making in the transition to sustainable energy. This study introduces S + HydPower, a tool coupled with SWAT+ to assess climate change and watershed management effects on small hydropower plant (SHP) systems. In this study, we used this tool to investigate the consequences of implementing environmental flows and climate change on run-of-river SHPs in the Catalan River Basin District (CRBD), in Catalonia. The results show that applying environmental flows would lead to a significant 27% reduction in SHP production. However, this reduction would represent only 0.25% of the region's current energy demand. Furthermore, the study reveals a potential 38% to 73% reduction in SHP production by the end of the twenty-first century due to the combined effects of environmental flows and climate change. This suggests a substantial decline in run-of-river SHP's contribution to the CRBD's electricity supply. These findings emphasize the need to explore alternative and sustainable energy sources to ensure the long-term reliability and resilience of the region's energy supply. [ABSTRACT FROM AUTHOR]

In light of the recent rise of authoritarianism and processes of 'democratic backsliding' in the Balkans (and other parts of CEE), the EU has projected an image of itself as a bastion of democracy and a counterweight to authoritarian tendencies and regimes. In contrast, this article points to the ways in which the EU – through its enlargement strategy – has legitimized authoritarian practices in candidate states. These practices have been inherently linked to the adoption of the EU acquis communautaire and deepening processes of neoliberal restructuring. In Serbia, the mandated transition to renewable energy, and the associated rise in small hydropower as a solution for meeting renewable energy targets, has led to an intensification of state-sponsored violence and coercion. By focusing on a small hydropower development in Rakita, Serbia, this paper highlights the inherently multiscalar nature of authoritarian state power and potential new avenues for contestation. [ABSTRACT FROM AUTHOR]

The lack of some hydrological data or short hydrological sequences makes it difficult to predict the power generation capacity of small hydropower stations, and this paper summarises three prediction methods: ARIMA model, LSTM model, and large and small hydropower station correlation method, in order to effectively solve this problem. Taking Ni'ao Gia Ga power station in Gannan area as an example, with the actual power generation data of the power station in 2022 as the test standard, and based on the power generation and water inflow data from 2015 to 2021, ARIMA model, LSTM model and large and small hydropower station correlation method are successively used to predict the power generation capacity of small hydropower stations in this area. The results show that the correlation method of large and small hydropower stations using the flow of large hydropower stations as the relevant factor can effectively predict the amount of water coming from small hydropower stations, and then get the prediction results of power generation with higher accuracy, which is obviously better than the ARIMA model and the LSTM model, and it can be popularised and applied in similar areas. [ABSTRACT FROM AUTHOR]

Achieving a harmonious alignment between the biological characteristics of fish and hydrodynamics patterns is crucial for ensuring the efficacy of fish passage facilities. In this study, based on the hydrodynamic characteristics of the river and the biological characteristics of fish, we evaluated the internal flow field in the nature-like fishway of Congen II hydropower station located along the Chabao river and explored methods to improve the operation efficiency. Based on comprehensive considerations of the flow field, turbulent kinetic energy, and the migration pathways of fish, it is found that the implementation of a continuous oblique bottom slope represents a more cost-effective and operationally convenient solution. The influence of different permutation of bulkheads in the nature-like fishway on operational efficiency was further examined. Our investigation revealed that the nature-like fishway with the continuous slope of 2% and the arrangement of three bulkheads in each row (model 3) exhibited a relatively simple velocity distribution and linear flow line, which poses challenges for fish in locating resting areas. In addition, the distribution of low turbulence kinetic energy area in the mainstream made it less favorable for fish to transition from the mainstream to the rest area within the fishway. The nature-like fishway with the continuous slope of 2% and the arrangement of two or three bulkheads in staggered rows (model 4) demonstrated better performance. Several potential fish migration routes for both model 3 and model 4 were proposed based on the numerical simulation results. In model 3, fish exhibited a continuous sprint through the concentrated high-speed area, which was less favorable for fish to rest and forage. In contrast, model 4 exhibited a diversified flow velocity distribution, enabling fish to make timely changes in their direction during migration. This feather proved to be advantageous in enhancing fish migration within the passage. The design of nature-like fishway in this study provides an important reference and technical support for the construction and optimization of the nature-like fishway for low dams, and is of great significance for restoring river connectivity destroyed by small hydropower construction and improving fish migration. [ABSTRACT FROM AUTHOR]

The Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) has been applied to simulate the flow through a Gravitational Vertical Turbine (GVT) configuration and the motion of the turbine of a small hydropower system. The turbine blades are assumed to be rigid bodies moving with one-degree of freedom, which is the rotation about its shaft due the hydrodynamic forces of the flow. The intake flow is an open channel flow which falls into a cylindrical basin which houses the turbine and impinges on the turbine blades. The method of simulation is the Weakly Compressible Smoothed Hydrodynamics (WCSPH) with the turbulence models in the equations of motion and the boundary conditions. The results are compared with a laboratory experiments conducted for the same dimension and the configuration. The flow features agree well and the motion of the turbine with a representative mass and a load agrees reasonably with the laboratory experiments [ABSTRACT FROM AUTHOR]

Due to the weak network architecture of mountainous power grid rich in grid-connected small hydropower, once the small hydropower units operate independently as a network when the upper power grid fails and loses power, the reliability of the power supply could be effectively improved. To cope with the problem of insufficient frequency regulation capacity of small hydropower units and the large risk of separation fault, this paper proposes a piecewise variable coefficient PID control strategy which improves the speed regulation control strategy of hydropower units, and a joint frequency regulation strategy of hydropower energy storage is designed to optimize the system operation state. Based on the MATLAB simulation platform, a hydropower energy storage microgrid model of mountainous power grid was built to verify the effectiveness of the segmented variable parameter control strategy. Using the proposed control strategy, the hydropower intelligent control terminal was developed and put into application in a certain area of Guangdong. Through simulation analysis and engineering applications, the practicality of the application of device engineering is verified to have good application and promotion value for a multi-hydropower mountainous power grid.

South Sudan is focusing on the development of large hydropower (LHP) to urgently improve access to electricity in the country. However, LHP investments are expensive and take many years to construct. SHP can be deployed as an alternative to LHP developments as they can be constructed in a shorter time and urgently deliver electricity to locations in need. This study aims to assess run-of-river (ROR) SHP potential in Central Equatoria State (CES) in South Sudan. This is the first study to assess the SHP potential in South Sudan. The main contribution of this research is to produce a dataset showing the geographical locations and generation capacities of the potential SHP sites. The objective of this study is to identify candidate SHP sites in the study area, investigate their suitability for ROR plants and estimate their electricity generation potential. A digital elevation model and a stream network were used to locate sites with a minimum elevation drop of 5 meters, along third and fourth order streams. The Soil and Water Assessment Tool (SWAT) model was used to estimate river discharges in the study area. Model calibration and uncertainty analysis were performed using the Sequential Uncertainty Fitting (SUFI-2) algorithm and daily flow duration curves at 95% dependability were developed from the simulated discharge data. The results showed the availability of eighty-two (82) potential SHP sites along the Bahr el Jebel and the Kaya rivers in CES with a total output power of 1651.69 MW and average annual output energy of 8.68 TWh. Around 60% of the sites had a minimum output power of 10 MW. The highest potential was found in sites between Rejaf and Mongalla, whereas the lowest was along the Kaya river. The study recommended economic analysis and environmental impact assessments before any SHP installation in the area.

The shaft hydropower plant (SHPP) is a novel hydraulic concept for low-head hydropower sites with several environmental and operational advantages over conventional layouts. However, the first two projects implementing this concept have shown comparatively high construction costs and project risks. Therefore, further optimization is required to increase economic attractiveness and enable broader market adoption. Initial model tests recommend a square-shaped shaft inlet with a three-sided approach flow for low-loss and fish-friendly inflow conditions. Yet, this design requires significant space for structural implementation and may be unsuitable for use with multiple shafts or as an extension of non-powered dams and weirs. This research paper presents the application of a computational fluid dynamics simulation setup to evaluate the hydraulic performance of various design configurations, especially alternative design layouts with a one-sided approach flow without further physical model tests. The simulation setup is calibrated against observations including head loss and velocity measurements from the physical model tests, and its satisfactory performance enables the analysis of alternative design layouts. This study aims to derive the most significant design parameters for achieving the desired hydraulic conditions at the intake. Increasing the flow depth before the intake and enlarging the inlet area have the most significant impact, while increasing the overflow of the front gate has the least significant effect. The chosen CFD application is deemed suitable for hydraulic design optimization and provides guidance on the key parameters to focus on for tailored site-specific design development.

This study focused on identifying potential locations for the implementation of Small Hydropower Systems to enhance the existing energy infrastructure in the Pumpum River Basin (PRB). Utilizing remote sensing and the Soil and Water Assessment Tool, basin parameters were generated and simulated for hydropower analysis. The energy potential of suitable sites was assessed through flow duration curves and power duration curves. The findings reveal that the PRB exhibits potential for small hydropower development, identifying nine sites along the river. The results of the model indicate power capacities of 1,521 kW for the Run of River and 2,290 kW for the dam sites respectively. The most promising hydropower sites were identified as dam site 1, river of run site 1, and dam site 6 with corresponding firm power of 2356.2 kW, 1567 kW and 264 kW, resulting in estimated firm energy production of 12.07 GWh, 8.03 GWh, and 1.35 GWh, respectively. Considering the suitable spacing of more than between 12 km among dam site 1, river of run site 1, and dam site 6 and a combined annual energy production of 21.65 GWh, a recommended approach involves establishing a cascade hydropower arrangement at sites dam site 1, river of run site 1, and dam site 6 along the Pumpum River. With a plant capacity of 65% to 90% dependability range, incorporating an installed Francis turbine, the total annual firm energy that can be produced from the nine (9) (Run of river and dam) projected sites ranges between 0.69 and 12.07 GWh. [ABSTRACT FROM AUTHOR]

There exist several renewable energy resources within the African continent. Quite a lot of attempts have been made to study these small hydroelectric sites and ways to harness them. Nevertheless, the majority of these potential sites remain undeveloped. Several countries within the African region such as Togo, Tanzania, Kenya, Ghana, and many others continue to experience a cyclical national power crisis, which is mostly attributable to insufficient power output to meet the continuously rising demand. An increase in electricity demand is unavoidable as the nation works to grow its economy, and more electricity generation will be required to power both established and new sectors. Several villages within the sub-Saharan region have lived with no electrical energy access for several decades now. The majority of these nation's current power generation portfolio is made up of a combination of hydro and thermal power plants, and for a while now, any temporary increase in generation has been achieved by the addition of new thermal power plants, even though these fossil fuels are occasionally in short supply. The country enters a constant cycle of power rationing with serious negative effects on industry and homes due to seasonal reductions in water inflows into hydropower facilities and occasionally difficulty obtaining crude oil or natural gas. Potential problems of this energy crisis are the high demand for electricity caused by certain factors its supply challenges and the lack of structural supply of electricity to consumers.it is therefore important for the entire globe particularly the developed countries to alleviate Africa from the high energy demand and poverty as a result of the energy crisis.

This paper focuses on the prospects of small hydropower plants (SHP) in Nigeria and utilizes ArcGIS software for analyzing the country’s hydropower energy potential. The analysis conducted using ArcGIS reveals the significant SHP potential in various states across Nigeria. By overlaying water areas and waterline data on maps, potential sites for SHP are identified, particularly in states such as Borno, Niger, Edo, Anambra, and Jigawa. Further analysis was done using data for water lines in Nigeria converted into shaped files for the six geopolitical zones of Nigeria, with the various states and local government areas, to provide expanded views for different possible schemes for SHP. Data set were built up for the different geopolitical zones and statistical analyses were done for SHP potentials. Interpolations were performed using Inverse Distance Weighting (IDW) tool on ArcGIS to show areas ideally suitable to site dam schemes for hydropower production and other schemes that require less water storage for small hydropower production. The strengths of each state in the various zones with regard to water inlands and lands subject to inundation were also identified. Some major challenges and opportunities in using ArcGIS in assessing small hydropower schemes in Nigeria, were also highlighted.

Abstract Background Hydropower is a mature energy technology and one that could play a more important role in providing clean and reliable energy. In small-scale contexts, hydropower is useful for providing electricity access, balancing intermittent resources, and as a potential source of energy storage. This paper provides a comprehensive exploration of the development of the small hydropower (SHP) sector in Indonesia, the world’s fourth most populous country. Methods Two research methods were employed: secondary data analysis through a desk review of relevant literature and primary data collection through site visits and expert and stakeholder interviews. Two case studies of micro-hydro applications in community-based rural electrification were analyzed. The paper explores how SHP projects were initiated, lessons learned, and policy recommendations of relevance to further development of distributed small-scale renewable energy in Indonesia. Results The sector commenced during the Dutch Era and now centers on both community-based rural electrification projects and commercial schemes under the independent power producer (IPP) approach. Since the late 1980s, initiatives to implement SHP for rural electrification have flourished through various programs. Key regulatory, economic, and technical barriers include inconsistent and unclear supporting regulations, especially regarding electricity prices; artificially low retail electricity prices; capital and borrowing constraints; advantages provided to fossil fuels; limited technical experience and capabilities of project developers and project sponsors; risks from floods, earthquakes, and landslides; constraints on supporting infrastructure; and limited grid links. The most successful and sustainable SHP projects are ones that provide local economic benefits and for which local communities are empowered with ownership and have responsibility for maintenance. Conclusions SHP will remain small from a macro perspective but could still play a key role in further improving energy access and equity in remote areas. Key initiatives to facilitate this development could include local-level capacity building and project participation and the adequate pricing of negative externalities from fossil fuel projects. Indonesia’s long experience with SHP carries lessons for other developing countries.

This study focused on identifying potential locations for the implementation of Small Hydropower Systems to enhance the existing energy infrastructure in the Pumpum River Basin (PRB). Utilizing remote sensing and the Soil and Water Assessment Tool, basin parameters were generated and simulated for hydropower analysis. The energy potential of suitable sites was assessed through flow duration curves and power duration curves. The findings reveal that the PRB exhibits potential for small hydropower development, identifying nine sites along the river. The results of the model indicate power capacities of 1,521 kW for the Run of River and 2,290 kW for the dam sites respectively. The most promising hydropower sites were identified as dam site 1, river of run site 1, and dam site 6 with corresponding firm power of 2356.2 kW, 1567 kW and 264 kW, resulting in estimated firm energy production of 12.07 GWh, 8.03 GWh, and 1.35 GWh, respectively. Considering the suitable spacing of more than between 12 km among dam site 1, river of run site 1, and dam site 6 and a combined annual energy production of 21.65 GWh, a recommended approach involves establishing a cascade hydropower arrangement at sites dam site 1, river of run site 1, and dam site 6 along the Pumpum River. With a plant capacity of 65% to 90% dependability range, incorporating an installed Francis turbine, the total annual firm energy that can be produced from the nine (9) (Run of river and dam) projected sites ranges between 0.69 and 12.07 GWh.

Electricity is the core of every nation's socioeconomic development. Nigeria depends heavily on fossil fuel for electricity generation due to the vast deposits of crude oil and natural gas in the country. Nevertheless, the vast deposit of crude oil, Nigeria still generates less than 4000 MW of electricity with per capita consumption of about 0.03 kW. Hydropower, being one of the available sources of energy, can be transported instantaneously and pollution free to the consumers making it attractive as compared to other forms of energy. Hence, the authors reviewed the available literatures on hydropower generation to evaluate its sustainability in Nigeria context. The literature search was made as wide as possible to capture all relevant data required. The searches covered databases specific to scholarly articles on hydropower generation sustainability. From the studies, it is shown that the potentials of hydropower generation in Nigeria if fully exploited can significantly improve the energy mix of the country that would sustainably serve its population. [ABSTRACT FROM AUTHOR]

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.

Background: Hydropower is a mature energy technology and one that could play a more important role in providing clean and reliable energy. In small-scale contexts, hydropower is useful for providing electricity access, balancing intermittent resources, and as a potential source of energy storage. This paper provides a comprehensive exploration of the development of the small hydropower (SHP) sector in Indonesia, the world's fourth most populous country. Methods: Two research methods were employed: secondary data analysis through a desk review of relevant literature and primary data collection through site visits and expert and stakeholder interviews. Two case studies of micro-hydro applications in community-based rural electrification were analyzed. The paper explores how SHP projects were initiated, lessons learned, and policy recommendations of relevance to further development of distributed small-scale renewable energy in Indonesia. Results: The sector commenced during the Dutch Era and now centers on both community-based rural electrification projects and commercial schemes under the independent power producer (IPP) approach. Since the late 1980s, initiatives to implement SHP for rural electrification have flourished through various programs. Key regulatory, economic, and technical barriers include inconsistent and unclear supporting regulations, especially regarding electricity prices; artificially low retail electricity prices; capital and borrowing constraints; advantages provided to fossil fuels; limited technical experience and capabilities of project developers and project sponsors; risks from floods, earthquakes, and landslides; constraints on supporting infrastructure; and limited grid links. The most successful and sustainable SHP projects are ones that provide local economic benefits and for which local communities are empowered with ownership and have responsibility for maintenance. Conclusions: SHP will remain small from a macro perspective but could still play a key role in further improving energy access and equity in remote areas. Key initiatives to facilitate this development could include local-level capacity building and project participation and the adequate pricing of negative externalities from fossil fuel projects. Indonesia's long experience with SHP carries lessons for other developing countries. [ABSTRACT FROM AUTHOR]

To achieve the net zero emission target by 2050, Taiwan is committed to promoting solar photovoltaic and offshore wind power. However, in order to ensure the stable supply of renewable energy, it should actively develop low-cost and mature base load renewable energy sources, such as small hydropower. By the end of 2021, Taiwan's hydropower (excluding pumped storage hydropower) had a total installed capacity of 2094 MW, accounting for 18.6% of the overall renewable energy ratio, with an average growth rate of 0.05% from 2016 to 2021. It is mainly limited by the need for low environmental and ecological impact, so it is relatively difficult to install large-scale hydropower; therefore, Taiwan has turned to the development of environmentally friendly small hydropower generation. In order to actively develop small hydropower generation and resolve development concerns, Taiwan has established a "Small Hydropower and Renewable Energy Development Strategy Platform". The current effective cases are mostly in the fields of the Taiwan Power Company, Water Resources Agency, and Council of Agriculture. The private sector has not yet shown its investment in the field. The reasons for this can be summarized as cumbersome administrative procedures, regulatory restrictions, insufficient economic incentives, and lack of technical capacity. The higher-level supervision mechanisms (such as the Executive Yuan level) are also the main key to whether small hydropower can be quickly promoted. In view of this, this study analyzes the current situation and policies to promote small hydropower generation policy recommendations through a literature review and comparison of international promotion experience. Some recommendations have also been incorporated into the newly revised Renewable Energy Development Act in 2023, such as relaxing the definition of small hydropower generation and incorporating water conservancy construction facilities that can be combined with power generation to improve site diversification. Other suggestions mentioned in the text can also be used as a reference for subsequent policy promotion in the future. [ABSTRACT FROM AUTHOR]

Small hydropower plays a pivotal role in flood retention and storage， runoff regulation， energy mix improvement， ecological environment protection acceleration， income increase of local farmers， and infrastructure enhancement. This paper expounds the necessity of the peak and valley time division adjustment based on the specific condition of a municipal power grid. Then the peak-valley time division adjustment situation and the FIT （feed-in tariff） of the small hydropower are provided. Finally， based on the review of measured data， including gateway electricity consumption and the output of small hydropower， the influence of the peak and valley time division adjustment on small hydropower is analyzed. The results show that the adjustment of peak and valley time can change the power generation behavior of small hydropower and ease the condition of peak-valley inversion in the gateway between day and night.

Small hydropower has attracted extensive interest as a clean technology. This study first identified possible sites of small hydropower plants with estimated capacity, and then utilized resources time footprint as a novel way to evaluate the impact of small hydropower plants on the aspects of materials, CO 2 , labor, and land. Resources time footprint is a sustainability indicator that uses a uniform time unit (years). It assesses whether the usage of resources exceeds the amount allocated to different people and generations. The smaller the value of resources time footprint, the more environmentally friendly is the process. Preferential locations for small hydropower in Dan River were specified, with a potential capacity ranging from 273 to 1175 kW. Resources time footprint of copper is 8.9–47.3 times as large as that of steel. Resources time footprint of CO 2 emissions is much smaller than that of other aspects, revealing that small hydropower has a great potential to mitigate the greenhouse effect. The overall resources time footprint decreases with an increase in the installed capacity. The methodology proposed in this study can be used to identify the ideal locations for setting up small hydropower plants in other regions as well. • We used resources time footprint to assess the impact of renewable energy. • We analyzed occupancy of materials, CO 2 emissions, land, and labor of SHP. • We made an initial attempt to apply resources time footprint to site selection. • Overall resources time footprint decreases with an increase in the capacity of SHP. • We identified preferential locations of SHP in Dan River Basin, China. [ABSTRACT FROM AUTHOR]

Optimising energy use in systems and buildings is crucial to reduce climate change. This paper aims to address the gap in knowledge for pico-hydropower (

Energy supply that is sustainable, effective, and economical has a strong association with socio-economic growth, particularly in developing countries such as Pakistan. Due to the ever-increasing gap between supply and demand, Pakistan has become an energy-deficient nation, with most people having no-to-limited access to power. Pakistan has been suffering from power shortages and an energy crisis because of its strong reliance on fossil-fuels to provide expensive electricity. Therefore, this paper offers a novel concept for developing Pakistan's energy by producing small-hydropower using Pump-As-Turbine (PAT), which is a form of Renewable-energy with lower environmental-impact and has not been used in Pakistan previously. PATs have shown several advantages over traditional hydro-turbines, such as minimum expenses, low-complexity, short delivery time, ease of spare parts, easy installation, availability in a large number of standard sizes, and massive production for broad-range of heads and flow rates. According to technical standards, any sort of pump could be used as PAT, including radial, mixed, single-stage, multi-stage etc. for power generation, which are capable of producing 5kW–1000kW of power, depending on their usage. However, Pakistan has shown little to no interest in exploring small/micro hydropower generation (PATs technology). Thus, this study offers public awareness and forward thinking regarding the use of advanced SHPs and draws the interests of legislators and different investors via solid recommendations about the cost-effective and environmental-friendly technology (PAT).

Rivers in tropical climates are characterized by highly variable flows which are becoming more variable due to climate change. In tropical conditions, most hydropower plants are designed as run-of-river plants with limited water storage. The aim of this study is the selection and sizing of a hydropower plant for highly variable flows, using the Sebeya River as a case study. As is often the case, flow data was incomplete, and the study also demonstrated the use of machine learning to predict the Sebeya flow rate for 2019. Stochastic modeling was used to estimate the energy generation for multiple turbine types and the levelized cost of energy for all configurations, capturing the uncertainty in many of the input parameters. River flow varies between 1.3 m3/s and 5.5 m3/s in a year; the minimum LCOE occurs at the knee in the flow exceedance curve of river flow rate, near 1.8 m3/s. The optimal LCOE for the Sebeya river is around 0.08 $/kwh with an uncertainty of −0.011/+0.009 $/kWh. Additionally, certain turbine types—notably propeller turbines—perform poorly in this type of highly variable flow. The method and findings can be used to guide future investments in small- to mid-sized hydropower plants in similar climatic conditions. [ABSTRACT FROM AUTHOR]

Hydropower is powered by water, making it a clean source of energy. It contributes about 17% of worldwide annual energy generation and 90% of national energy generation, out of which 25% of its generation is contributed by small hydropower plants (SHPs). Thus, Nepal is predominantly dependent on a clean source of energy for power generation. In quantitative terms, approximately 70% of hydropower plants in Nepal are SHPs. Unfortunately, there are several bottlenecks to the smooth operation of these plants, viz. run-off-river hydropower with low water flow in dry season, insufficiency of proper guidance monitoring, regularization and inadequate and unfriendly policies. The study is based on primary and secondary data considering the SHPs spreading from eastern to western Nepal. Furthermore, the study follows the multicriteria decision analysis method to generalize the major issues at the sites. Inadequate water flow in the dry season is not the only issue for reduction in power generation; mechanical failure due to lack of monitoring and periodical maintenance is the predominant reason for the reduction in power output. This study discusses the role of reduction in water flow, unavailability of a trained workforce in rural hydropower areas, absence of appropriate equipment monitoring guidelines and inconsistent maintenance in the equipment failure and power production of hydropower plants. Every one in three SHPs has issues with smooth operation in terms of generation capacity, and overall, 50% of SHPs have mechanical issues as the major problem, which concludes the findings of the research. [ABSTRACT FROM AUTHOR]

During operation Pelton turbines suffer from erosion and cavitation wear, which decreases the hydraulic efficiency. Welding repair is a cost-effective method for recovering the original bucket geometry but requires templates to ensure proper results. However, those templates may be unavailable for Pelton units with decades of operation. This is the case of one of the 2.8 MW Pelton units at Nima II, a small hydropower plant in Colombia that began operation in 1942. This paper presents the redesign and optimization of the bucket. First, the bucket is rebuilt following both, technical recommendations, and Design of Experiments (DOE) to verify the effects of the basic dimensions on the hydraulic efficiency. Experimental measurements on the eroded turbine validate the two-phase computational fluid dynamics (CFD) modelling to be applied in the optimization process. Second, the best inner surface is found by using a multi-objective optimization based on Artificial Neural Networks trained by the previous DOE and a genetic algorithm. At the end, the CFD results suggest a total hydraulic efficiency recovery of 8 %. Further experimental tests on the optimized runner showed a difference of 0.7 % from the predicted value. [ABSTRACT FROM AUTHOR]

The energy harvesting performance of a hydrokinetic turbine in a confined channel has been investigated through numerical simulations. It consists of a two-bladed vertical-axis turbine with a NACA0015 profile. Fluid dynamics are reproduced by a 2D numerical model solving the unsteady RANS equations through a finite volume approach in OpenFOAM-v6. Following a numerical sensitivity analysis, the baseline model has been validated with respect to reference data for an unconfined turbine with similar design. The model has then been employed for assessing the influence of the main design parameters – namely blade-channel gap ε0, solidity σ and tip-speed ratio λ – on the performance of the turbine. First, a parametric study on the plane λ×σ revealed that best performance is obtained at high solidity and low tip-speed ratios. In a range of solidities from 0.06 up to 0.48, the optimal value of tip-speed ratio – which is considerably higher when compared with unconfined turbines – is precisely identified. Finally, the effects of the blade-channel gap ε0 on the performance of the turbine has been investigated as well. It has been found that ε0 should be set as small as possible in order to maximise energy harvesting. Moreover, numerical results allowed for estimating a limit value of ε0>9 over which the performance of a turbine operating in a confined channel should match that of an unconfined turbine.

The role of renewable energy sources is increasing in recent times. Among the various renewable energy sources, small hydropower is considered the most promising energy source. For proper operation of the power plant, the annual generation and operational cost are the two main aspects. In order to maintain the economy of operation, it is necessary to minimize the operation cost with improved performance. In the present study, the operation cost data collected from such a plant have been analysed to develop correlation for run-of-river small hydropower schemes, considering installed capacity and head as cost-influencing parameters. The validation of the developed correlations has also been carried out, and it has been found that the correlation developed for operation cost can be used to determine the operation cost at the planning stage. [ABSTRACT FROM AUTHOR]

During the last years, significant changes happened in seasonal river hydrology in Europe due to climate change. Nevertheless, according to the presented analysis, the total water runoff for hydropower generation did not change. The last fact is an important policy implication for small hydropower promotion in Ukraine because it belongs to that region and has similar climate conditions. Having analysed the hydropower potential, the paper describes the main advantages and limitations of implementing small hydropower projects in Ukraine. The cost of electricity generated by a small hydropower plant in Ukraine is determined and compared with the current feed-in tariff. The calculations show that the feed-in tariff is 1.4 times higher than the electricity generation cost, making the implementation of small hydropower plants profitable for investors. Since the state provides sufficient economic support for this sector's development, the financial and non-economic barriers significantly hinder small hydropower plant deployment are considered. [ABSTRACT FROM AUTHOR]

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

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

Trash racks are usually composed of an array of bars installed in a hydropower scheme to safeguard the turbines by collecting water-borne detritus. However, current design approaches for the design of trash racks focus on structural criteria. A little attention renders the proper evaluation of hydraulic criteria, which causes a significant hydraulic head loss in low head hydropower schemes with an integral intake. This study investigates the head loss through trash racks by employing computational fluid dynamics (CFD) for several design combinations. A three-dimensional model of trash racks using fractional area/volume obstacle representation (FAVOR) method in FLOW-3D is set up to define the effects of the meshing on the geometry and several simulations are carried out considering various approach velocities and different bar spacings, inclination angles, and blockage ratios. The results indicate that head loss increases with an increase in approach velocity, the inclination angle of the rack with channel bed, and blockage ratio. It is noticed that a clear spacing between vertical bars greater than or equal to 0.075 m has a minimum head loss before it becomes significantly high for lower spacing. In addition, the head loss coefficient increases for screen angles greater than 60°, which can be considered as an optimal parameter for design purpose. [ABSTRACT FROM AUTHOR]

To achieve the net zero emission target by 2050, Taiwan is committed to promoting solar photovoltaic and offshore wind power. However, in order to ensure the stable supply of renewable energy, it should actively develop low-cost and mature base load renewable energy sources, such as small hydropower. By the end of 2021, Taiwan’s hydropower (excluding pumped storage hydropower) had a total installed capacity of 2094 MW, accounting for 18.6% of the overall renewable energy ratio, with an average growth rate of 0.05% from 2016 to 2021. It is mainly limited by the need for low environmental and ecological impact, so it is relatively difficult to install large-scale hydropower; therefore, Taiwan has turned to the development of environmentally friendly small hydropower generation. In order to actively develop small hydropower generation and resolve development concerns, Taiwan has established a “Small Hydropower and Renewable Energy Development Strategy Platform”. The current effective cases are mostly in the fields of the Taiwan Power Company, Water Resources Agency, and Council of Agriculture. The private sector has not yet shown its investment in the field. The reasons for this can be summarized as cumbersome administrative procedures, regulatory restrictions, insufficient economic incentives, and lack of technical capacity. The higher-level supervision mechanisms (such as the Executive Yuan level) are also the main key to whether small hydropower can be quickly promoted. In view of this, this study analyzes the current situation and policies to promote small hydropower generation policy recommendations through a literature review and comparison of international promotion experience. Some recommendations have also been incorporated into the newly revised Renewable Energy Development Act in 2023, such as relaxing the definition of small hydropower generation and incorporating water conservancy construction facilities that can be combined with power generation to improve site diversification. Other suggestions mentioned in the text can also be used as a reference for subsequent policy promotion in the future.

Small hydropower has received a great interest in recent years as a source of renewable energy with low investment costs for providing electricity worldwide. Small hydropower does not require construction of large dams compared to the large hydropower stations. The aim of the present study is to provide: (1) detailed performance measurements on a micro Pelton turbine model, (2) detailed measurements on a modified small scale ram pump system based on the principle of water hammer phenomenon, and (3) propose a new hydraulic system to operate the micro Pelton turbine model at the best efficiency point, but at a very low static pressure head of water. A simplified mathematical model was developed and its results were satisfactory and in line with the theory of the Pelton turbine, verifying similarity and repeatability of the model for estimating the turbine performance. The operating conditions (net head and flowrate) of the experimental 10W micro Pelton turbine model with a single nozzle are 20 m of water and 33.01 l/min. Integrating the proposed hydraulic system with the base Pelton turbine model shows that the best efficiency point is reached at a total flow rate of 33 l/min and at only 2.5 m pressure head. [ABSTRACT FROM AUTHOR]