Search

MHP is a renewable energy technology that transforms the kinetic energy of flowing water into electrical power. With the rising interest in sustainable energy, there is a potential for enhanced integration of micro-hydropower (MHP) with water distribution networks (WDNs) for energy generation and pressure regulation. The deployment of this technology in Malaysia has been impeded by several obstacles. The possibility of integrating MHP into WDNs will be assessed in the context of Malaysian urban environments. The evaluation emphasizes that WDNs ensure consistent water flow and quality, hence decreasing operational expenses and turbine degradation, rendering MHP a dependable and sustainable energy source. Analysis indicates that interest in MHP escalated in 2011, with pertinent studies rising by 70% by 2020. MHP systems are feasible for decentralized and sustainable energy production; nevertheless, problems including infrastructure constraints, substantial initial costs, and the requirement for technical proficiency persist. This study examines MHP systems, including their classification, components, power production, and efficiency within the specific infrastructural and energy context of Malaysia. The article evaluates Malaysia's hydropower potential in water distribution networks, utilizing methodology derived from successful European models, and examines how strategic policies could enhance installed capacity. The findings indicate that Malaysia may achieve its renewable energy objectives by formulating effective policies to optimize the current water infrastructure, while promoting environmental, economic, and energy security aims. Malaysia can lead Southeast Asia's sustainable energy initiatives by advancing micro-hydropower, hybrid energy systems, and community engagement. The evaluation aims to guide future research and policy initiatives to expedite the country's energy transformation through the integration of micro-hydropower in water distribution networks. [ABSTRACT FROM AUTHOR]

Abstract Literature shows that only 56% of Kenyan households had access to electricity, with rural areas having the lowest access rate at percent. The high cost of extending the power grid to remote areas and power losses on distribution are significant challenges facing rural electrification. In addressing power accessibility problems, especially in rural areas, there is a need for tapping hydropower generation through the invention and implementation of in‐duct turbines to maximize the utilization of already existing pressurized water ducts that supply water in various parts of Kenya for hydropower generation. Makueni County is endowed with gravity‐fed water ducts with high potential for hydropower which can innovatively be produced by application of in‐duct turbines. This paper focuses on the assessment of energy needs and applications in rural areas. The research design was exploratory and experimental in nature. It was exploratory because, through an assessment, it sought to explore and identify the potential areas within the water supply lines for the production of hydropower to supply hydropower in Makueni County. It was experimental because the researcher developed (designed and fabricated) a hydro turbine for use in the production of hydropower from gravity water ducts of a diameter raging 100 mm. The research revealed that 62% (98) used solar power for lighting their homes, while 17% (28), 12% (20), and 8% (12) used lanterns, electricity, and kerosene lamps, respectively. Among the fuels assessed was firewood which was identified as the most used fuel at 89% (140). This was followed at a distance far by paraffin at 6% (9) of respondents. The households at 100% (158) identified electricity as a potential source of lighting for their household. The study recommends harnessing hydropower to enhance reach to 100% of the rural communities. The energy availability will provide opportunities for communities and institutions in rural areas to open their minds to business development and engage in income‐generating activities like the rearing of poultry and the development of light industries like the gridding of maize and other cereals.

Literature shows that only 56% of Kenyan households had access to electricity, with rural areas having the lowest access rate at percent. The high cost of extending the power grid to remote areas and power losses on distribution are significant challenges facing rural electrification. In addressing power accessibility problems, especially in rural areas, there is a need for tapping hydropower generation through the invention and implementation of in‐duct turbines to maximize the utilization of already existing pressurized water ducts that supply water in various parts of Kenya for hydropower generation. Makueni County is endowed with gravity‐fed water ducts with high potential for hydropower which can innovatively be produced by application of in‐duct turbines. This paper focuses on the assessment of energy needs and applications in rural areas. The research design was exploratory and experimental in nature. It was exploratory because, through an assessment, it sought to explore and identify the potential areas within the water supply lines for the production of hydropower to supply hydropower in Makueni County. It was experimental because the researcher developed (designed and fabricated) a hydro turbine for use in the production of hydropower from gravity water ducts of a diameter raging 100 mm. The research revealed that 62% (98) used solar power for lighting their homes, while 17% (28), 12% (20), and 8% (12) used lanterns, electricity, and kerosene lamps, respectively. Among the fuels assessed was firewood which was identified as the most used fuel at 89% (140). This was followed at a distance far by paraffin at 6% (9) of respondents. The households at 100% (158) identified electricity as a potential source of lighting for their household. The study recommends harnessing hydropower to enhance reach to 100% of the rural communities. The energy availability will provide opportunities for communities and institutions in rural areas to open their minds to business development and engage in income‐generating activities like the rearing of poultry and the development of light industries like the gridding of maize and other cereals. [ABSTRACT FROM AUTHOR]

Many nations across the globe have incorporated carbon neutrality into their national agendas to see a more sustainable world. The basic sustainable journey is to find the equilibrium between the people, the environment and the economy. By conceptualizing inclusive carbon-neutral electrification, countries may achieve their aspiration at both the macro and micro levels. Macro national energy transition policies emphasized centralized technological shifts for grid systems and in many cases neglected rural communities. Some argued that Borneo's disparity in socioeconomic status was due to a lack of electrification. Hence, this paper explored the decentralized community-based electrification potential through a micro hydropower initiative. Such technologies encourage watershed management and are closely related to the Tagal communities' heritage. The paper explored the complex problem with the multihelix approach to examine each actor's aspirations and concerns. Actors underwent a series of interviews based on five key aspects of sustainable rural electrification. By integrating multicriteria analysis (MCA), the qualitative research data were analyzed to find gaps for implementation. The findings supported the introduction of a new actor to best foster inclusive watershed management through micro hydropower electrification in Sabah, Malaysia. [ABSTRACT FROM AUTHOR]

This study discusses the numerical optimisation and performance testing of the turbine runner profile for the designed gravitational water vortex turbine. The initial design of the turbine runner is optimised using a surface vorticity algorithm coded in MATLAB to obtain the optimal stagger angle. Design validation is carried out using computational fluid dynamics (CFD) Ansys CFX to determine the performance of the turbine runner with the turbulent shear stress transport model. The CFD analysis shows that by optimising the design, the water turbine efficiency increases by about 2.6%. The prototype of the vortex turbine runner is made using a 3D printing machine with resin material. It is later tested in a laboratory-scale experiment that measures the shaft power, shaft torque and turbine efficiency in correspondence with rotational speeds varying from 150 to 650 rpm. Experiment results validate that the optimised runner has an efficiency of 45.3% or about 14% greater than the initial design runner, which has an efficiency of 39.7%. [ABSTRACT FROM AUTHOR]

There is a significant hydropower potential in irrigation canals worldwide. Much of this potential exists as energy dissipating ramp-type fall structures. Hydropower could be employed to pump water for water saving irrigation, or to generate electricity. This hydropower is unused, since there are no cost-effective hydropower converters for the specific conditions in irrigation canals, i.e. head differences from 0.3 to 5 m and flow volumes ranging from 0.1 to 15 m3/s. At Southampton University, a simple undershot impulse-type waterwheel with 180° jet deflection was developed specifically for this application. Large scale tests, with a scaling ratio of 1:2.4, showed efficiencies of 53%, confirming predictions from theory. The model employed a novel roller-type power take-off which eliminates the requirement for a cost-intensive gearbox. The impulse wheel has considerable development potential, and could be a cost-effective solution for small hydropower sites at ramp structures. [ABSTRACT FROM AUTHOR]

Micro hydropower power generates electrical energy to meet connected electrical demand, that normally fluctuates causing imbalances. Electronic load controller is then used to balance power system by diverting surplus generated power to the dump load commonly resistive load such as bulk water heater. This study investigated use of oil heating system as a replacement for conventional resistive dump load. In comparison to water, oil has high thermal retention therefore can serve as good thermal media. Dump load range ranged between 17 kW to 78 kW. A 6-kW electrical heater was used for laboratory oil heating system from which heated oil attained about 10,791 MJ in 31.5 minutes. Thermal stratification between upper layers and the lower layers of oil in storage tank decreases from 3.8° to 3.4° as oil temperature increases from 100° to 200°, respectively. Energy dissipated through dump load from micro hydropower plants is sufficient for domestic energy consumption including cooking. [ABSTRACT FROM AUTHOR]

Gravitational Water Vortex Power Plant (GWVPP) is one of the micro-scale hydropower system that is capable to convert rotational moving fluid to usable energy. It is preferred over other such systems because of its ultra-low operating heads and the system's ability to work with low flow rate to generate electricity. The ease of setup, low maintenance, and operating cost make it suitable for portable energy source applications. The novelty of this study is the dome-shaped basin GWVPP system; the design was inspired from the Brachistochrone curve theory. A Computational Fluid Dynamics (CFD) analysis study was used to investigate the formation of vortex, and determine and optimize the curve radii parameter for fabrication of the system basin. Two different dome basins were fabricated in this study; wide version and narrow version. A total of 30 experimental tests were made for the dome basin GWVPP system. The maximum efficiency of the system setup was recorded at 31.77%, obtained at the bottom of the dome-basin using angled-curved blades profile from narrow dome basin with smallest outlet diameter. This study shows that there is a possible alternative basin design for GWVPP system. [ABSTRACT FROM AUTHOR]

Micro hydropower (MHP) schemes play an important role in socio-economic development of an area. This study attempts to identify the effects of MHP schemes on productivity of maize crop in three selected tehsils namely Alpuri, Besham and Puran of district Shangla, Khyber Pakhtunkhwa, Pakistan. A total of 220 households were randomly selected from the selected tehsils. Primary data were collected through a questionnaire-based survey. Binary logit model was used to find out the effects of MHP scheme on productivity of maize crop in the research area. The results of the estimated model confirm that MHP scheme has a positively significant effect on productivity of maize crop and thereby, income of people in the study area, as shown by the p-value less than 0.05. The overall model was highly significant which confirms that MHP positively affects productivity of maize crop and income of the farmers. The study concludes that electricity produced from MHP schemes has an important role in socio-economic and sustainable agricultural development in the research area in specific and rural areas in general.

Rural electrification in developing countries is often hampered by major information gaps between local communities and urban centers, where technical expertise and funding are concentrated. The tool presented in this paper addresses these gaps to support the implementation of off-grid micro hydropower infrastructure. Specifically, we present a method to site, size and evaluate the potential for micro hydropower based on remote sensing data. The method improves on previous approaches by (i) incorporating the effect of hillslope topography on the optimal layout of the infrastructure, and (ii) accounting for the constraints imposed by streamflow variability and local electricity demand on the optimal size of the plants. An assessment of the method's performance against 148 existing schemes indicates that it correctly identifies the most promising locations for hydropower in Nepal, but does not generally reproduce the specific design features of constructed plants, which are affected by site-specific constraints. We develop a proof-of-concept computer tool to explore the potential of webGIS technology to account for these constraints by collecting site-specific information from local users.

Rural electrification in developing countries is often hampered by major information gaps between local communities and urban centers, where technical expertise and funding are concentrated. The tool presented in this paper addresses these gaps to support the implementation of off-grid micro hydropower infrastructure. Specifically, we present a method to site, size and evaluate the potential for micro hydropower based on remote sensing data. The method improves on previous approaches by (i) incorporating the effect of hillslope topography on the optimal layout of the infrastructure, and (ii) accounting for the constraints imposed by streamflow variability and local electricity demand on the optimal size of the plants. An assessment of the method's performance against 148 existing schemes indicates that it correctly identifies the most promising locations for hydropower in Nepal, but does not generally reproduce the specific design features of constructed plants, which are affected by site-specific constraints. We develop a proof-of-concept computer tool to explore the potential of webGIS technology to account for these constraints by collecting site-specific information from local users.

The small hydroelectric power plants (SHPP) are implemented in non-interconnected zones (NIZ) of developing countries. In which, the provision of electrical energy from the national interconnected system is not economically feasible. Therefore, in the literature, hydroelectric generation technologies have been implemented taking advantage of the energy available in the rivers. One of these technologies is the Michell-Banki type cross-flow turbines (MBT), which, despite having lower efficiencies than turbines such as Pelton and Francis, maintain their efficiency although fluctuations in site conditions. For this reason, different studies have been made to increase the efficiency of the MBT by making geometric modifications to both the nozzle and the rotor. The purpose of this study is to determine numerically the effect of the geometry of the blades that form the runner on the efficiency of Michell-Banki Turbine (MBT). For this, two (2) geometries were studied corresponding to a circular sector of a standard tubular profile and an airfoil NACA 6512 modified in curvature profile and chord length, according to the profile of the standard tubular blade. For this study, transient simulations for multiphase water-air flow were implemented using a k--ε turbulence model in the Ansys 2020R1® CFX software. The two (2) turbine models were configured to the same hydraulic conditions of head and volumetric flow corresponding to 0.5 m and 16.27 L/s, respectively. Variations in rotational speed were configured between 100 and 200 RPM with 20 RPM steps. It was found that using the modified 6512 hydrodynamic profile, at 140 RPM increased efficiency by 6 %, compared to the conventional tubular type blade geometry. [ABSTRACT FROM AUTHOR]

Water distribution networks often exhibit excess pressure that could lead to extensive leakage and infrastructure damages. While this problem can be mitigated with pressure reducing valves, the use of micro-turbines offers the additional benefit of harnessing the excess energy for electricity production. However, the efficient placement of turbines in a water distribution network constitutes a complicated optimization problem. The addition of a turbine in a water distribution network induces additional head losses and redistribution of the discharge within the network. This study considers the discharge redistribution as a key process for the maximization of power generation and presents a heuristic methodology based on nonlinear programming. Through an iterative process, pumps as turbines (PATs) are placed in pipes where the discharge has been increased due to previous placements of PATs elsewhere in the network. The suggested heuristic methodology is implemented in a synthetic network and the results are compared to the maximum power production from all possible combinations of PAT positionings in the network. Results show that the suggested methodology reduces considerably the number of combinations to be tested and it approaches satisfactorily the maximum possible power generation. In the synthetic network, the suggested methodology is able to predict almost the maximum possible power production with up to four PATs in the network and at least 87% of the maximum power production when five PATs are in the network. Finally, the suggested methodology is applied successfully to a real-world network, where it is able to identify the optimal location of one and two PATs. [ABSTRACT FROM AUTHOR]

This work aims to identify a cost-effective solution for improving the energy performance of a grid-connected prosumer, possibly equipped with electric vehicle chargers. The solution is based on a small-scale energy system based on renewable energy sources (RES). The system is equipped with an Archimedes Screw Turbine (AST) and photovoltaic panels. Energy storage in batteries is also considered. A simple yet efficient method for sizing the AST is proposed. A cost-benefit analysis of the small-scale energy system is performed for six case studies covering different combinations of energy consumers. Three economic scenarios are considered for each case study. The results suggest that the AST-based solution leads to reasonable costs for the prosumer and less impact of energy price fluctuations. Also, if EV chargers are used, their consumption can be covered directly by RES. [ABSTRACT FROM AUTHOR]

Undershot water wheels are hydropower converters for head differences between 0.5 and 1.5 m. The Zuppinger and Sagebien types are the most used and efficient. Optimal rotational speeds depend on the head difference and on the flow rate: hence, in variable flow rate applications, the variable rotational speed is needed to optimize the performance, requiring expensive power take-off systems. In light of this, the use of adjustable inflow weirs was tested on Zuppinger and Sagebien wheels. Different flow rates were tested, each one with an inflow weir height chosen to maintain the upstream water level constant through the tests. The first aim was to increase the power at very low flows. The second aim was to maintain the range of optimal rotational speeds as narrow as possible over the flow rate range. The maximum acceptable weir height ranged between 1:15 and 1:10 of the wheel's radius. [ABSTRACT FROM AUTHOR]

In recent years, pump-as-turbines (PATs) have been highlighted for their potential benefits as an application of micro-hydropower (MHP) in water distribution networks. However, PATs come with disadvantages of relatively low peak efficiencies, which can be reduced further with large flow fluctuations. MHP and PATs in particular applied in irrigation networks is a relatively new area of research focus for these devices, and one that poses significant opportunities for energy saving as well as significant challenges due to variations in flow rate. This paper discusses the validation of a statistical methodology to estimate the flow and head variability in a network, and to select PATs whose best efficiency point (BEP) returns the lowest payback period. A comparison between the predicted and actual occurrence probabilities for different flow rates was carried out at nine potential points for MHP installation identified within a real network in Southwestern Spain. For the flow occurrence probability, the coefficient of determination (R2) of 0.804. A total of 281.0 MWh were obtained from the flow prediction and PAT selection methodology, in contrast to 230.5 MWh using the actual measured data. An overall difference of 0.2% was obtained when both PATs were simulated under actual conditions. • The validation of a methodology for flow prediction and pump as turbine selection was carried out. • An average coefficient of determination of 0.804 was obtained for flow occurrence probability. • Difference of 22% on the energy recovery potential with predicted and actual conditions. • Difference of 0.2% was found when predicted pump as turbines were tested under real conditions. • In comparison to alternative approaches, this methodology represents a 7.4 and 38% improvement in accuracy. [ABSTRACT FROM AUTHOR]

Most renewable energy (RE) studies focus on technology readiness, environmental benefits and/or cost savings. The market permeation, viability and adoption of RE technologies such as micro hydropower (MHP), however, require the alignment of other interrelated factors, such as the socio-technical, institutional and political dimensions. This is particularly the case where the energy recovery potential in decentralised water networks is being explored as part of a wholesome sustainability strategy by and for individual and communal prosumers. This study employs a socio-technical approach to understand factors that influence the perceived viability and adoption of MHP in group water-energy schemes. Methods included a progressive literature review to formulate a conceptual framework for the implementation of MHP systems. The framework was validated using survey data from representative stakeholders from groups schemes in Ireland and Spain. These stakeholders were sampled and surveyed at the stage of considering the adoption of MHP in their water networks. The findings highlight the push–pull factors and discusses the opportunities and barriers to the adoption of MHP systems. It confirms that the market, institutional and policy context, cost and financial benefits, social support and collaborative services combine to influence the adoption of MHP technology. Thus, a framework for evaluating the socio-technical viability of MHP systems based on these more realistic integrated, multi-dimensional criteria is proposed.

Nepal has economically exploitable hydropower potential of about 42,000 Megawatts out of which only about 2% has been harnessed so far. Nepal's average annual per capita electricity consumption is about 161 kWh- one of the lowest consumptions in South Asia. Electrical energy available for the fiscal year 2016/2017 was 6257 GWh, of which NEA's own contribution was only 36.84% whereas those imported from India and local IPPs accounted for 34.76% and 28.40% respectively. Despite its vast hydropower potential, Nepal suffers from severe and long-lasting electricity supply crisis. The main objective of the study was to assess the current status of small/micro hydropower in Nepal through a case study of Giringdi SHP (75 kW), considered as an example of excellence in small/micro hydropower. Analysis was done based on the primary data that was accumulated via questionnaires, simple observation, and direct on-site testing of components. It was found that the condition of plant with regard to installed major equipment like turbine, generator, Electronic Load Controller (ELC), control valves, panel board and other electrical parameters were only satisfactory while the working condition of other components like bearings, shaft and couplings were considerably poor. Even the condition of one of the best sites, seemed to be satisfactory reflecting the frequency of maintenance and policies in rural off-grid/not connected region. Thus, this all shows that the government policy for off grid/not connection in comparison with pre-connection and post-connection strategy regarding national electrification plan needs to be revised and rethought for future development and growth of this sector. [ABSTRACT FROM AUTHOR]

Abstract Cross-flow turbine is a promising device for power supply to water monitoring sensors and meters along water supply pipes. In the previous research, an inline cross-flow turbine is proposed and the effects of blocks on turbine performance have been studied by numerical methods. Based on the results, mismatching exists between the flow inlet angle and blades outer angle, which may result in shock loss and flow separation. In this study, a numerical investigation was performed to study the effects of blades outer angle on the turbine performance. Results indicated that the matching between flow inlet angle and blades outer angle can enhance the torque output of runner first stage and significantly improve the overall turbine performance. To achieve a balance between turbine efficiency and water head reduction, the blades outer angle of the inline cross-flow turbine is suggested as 30°. [ABSTRACT FROM AUTHOR]

Continuous and reliable power supply plays an important role for water leakage monitoring systems used in urban water supply pipes. Renewable energies powered water leakage monitoring system is becoming a promising way to reduce the dependence on traditional chemical batteries. In this study, an inline vertical cross-flow turbine was developed to harvest the potential hydropower inside water supply pipes for supplying power to the water monitoring systems. Specifically, numerical investigations are carried out on the block shapes of a water turbine system to determine an optimal model. The effects of tip clearance on the turbine performance are conducted and it is found that a smaller tip clearance can reduce the reversing torque on the returning blades and increase the pressure drop through the runner for improving the turbine performance. Besides, a self-adjustable vane is designed to avoid excess water head loss. The simulation results show that the proposed self-adjustable vane is effective to limit the water head loss at high flow velocities (1.5–2.0 m/s) to 5 m. Finally, the turbine prototype is fabricated and tested on a lab test rig. The experimental results indicate that the numerical method adopted in this research is accurate enough for such micro water turbine performance prediction. A month-long test shows that the daily electricity generation of the proposed turbine is about 600 Wh and the water head loss is always below 5 m, which means that the proposed turbine can provide sufficient power for any general water leakage monitoring system without influencing normal water supply. [ABSTRACT FROM AUTHOR]

Highlights • A novel design method for inline cross-flow turbine used in water mains was proposed. • Effects of different block design on turbine performance were investigated. • The influence mechanism of block shape on turbine performance was studied by numerical methods. Abstract Cross-flow turbines offer a promising, cost-effective solution to harvest hydropower from water mains to supply power to water monitoring systems. However, the design and performance of cross-flow turbines in water mains have not been fully investigated. In this paper, an inline cross-flow turbine configuration with two blocks is proposed and a block design method is presented. Specifically, numerical investigations are carried out to verify the proposed method and study the effect of different block designs on turbine performance. Flow velocity analysis shows that the proposed block can improve the flow attack angle at the runner inlet and significantly increase the flow velocity through the runner. In addition, the pressure distribution indicates that the blocks can increase the pressure difference through the runner and thus improve turbine performance. A comparison of three models with different guide block orientation angles reveals that the model with the largest conversion block orientation angle performs best, because the blocks from this model not only function better in terms of flow separation and negative torque reduction at the first stage, but also convert more water head into kinetic energy. Numerical results show that the inline turbine can achieve its maximum efficiency of 42.4% with a power output of about 1500 W and that the water head reduction is limited within an acceptable range. [ABSTRACT FROM AUTHOR]

The inline cross-flow turbine is a promising and reliable device to harvest hydropower in an urban water supply pipeline for power supply to its water supply monitoring system. However, investigations about the influencing factors on the performance of inline cross-flow turbines are still rare and this paper focuses on the effect of their runner inlet arc angle for improving the device's performance. Firstly, a mathematical design method for the turbine's blocks is developed. With the proposed method, four models with different runner inlet arc angles are developed. The turbine's performance, function of conversion block, flow velocity characteristics, pressure distribution and blades torque output of the models are then analyzed. Results indicate that a smaller runner inlet arc can increase the flow velocity at runner inlet and pressure difference between the upstream and downstream of the runner, resulting in a higher output power but also a higher overall water head reduction through the turbine. Besides, it is found that the runner inlet arc angle has a significant influence on the power output of runner second stage. With the increase of runner inlet arc angle, the torque output at the second stage encounters a gradual decrease. To achieve a good balance between turbine efficiency and water head reduction, the suggested runner inlet arc angle is 105°. Numerical results showed that the model with 105° runner inlet arc angle could produce a maximum power generation efficiency of 42.6% with about 1.6 kW power output. [ABSTRACT FROM AUTHOR]

The objective of the study has been to determine the river discharge by measuring the river flow velocity using two different measurement methods together with the area method and compare the accuracy of the results. Two river flow velocity measurement methods were used, the floating method and the use of current meter. In floating method a floating object was used to determine the water flow velocity on the surface by allow a float to move a distance of 1 m along the river and record the time it takes to travel that distance in seconds. Ten readings were taken and manually recorded and the flow velocity was determined by taking the distance travel by the float (1 m) divide by the time taken by the float (in seconds). On the other hand, the current meter method measure directly the average flow velocity across the river depth, twenty readings were taken and recorded manually and the average velocity were calculated. The use of current meter display flow velocity directly without the need of calculations. The result shows that both methods produce very close value, but the floating method have displayed higher value of around + 2% than current meter method which is a good value, despite the fact that floating method measures the surface velocity and the use of calculation. Many literature highlighted the accuracy of flow velocity measurement using current meter due to the fact that it measures the average velocity across the river, but from the findings when the floating method flow velocity measurement is properly applied it will produce as accurate results as the current meter with a fraction of cost in terms of instrument cost and expertise requirement in measurements. The floating method flow velocity measurement method could be applicable as alternative to current meter in micro hydropower projects river flow measurements in rural areas of developing countries with limited funding and local expertise. [ABSTRACT FROM AUTHOR]

Water leakage monitoring system is essential for the urban water supply, but it is a great challenge to ensure stable and reliable power supply for this system. In this study, an inline cross-flow turbine was proposed to harvest hydropower from the water pipes. A numerical investigation was conducted to study the effects of blocks on the turbine performance. The simulation results indicated that the proposed upstream and downstream blocks can act as nozzle and diffuser in traditional cross-flow turbine to enhance the flow velocity and pressure difference through the impeller, so the turbine performance can be improved. The maximum output power of the turbine can research 136W when the TSR is 1.2 and the water head loss through the water turbine is in the range of 3.45m-3.75m water head, which has little negative impact on the normal water supply. [ABSTRACT FROM AUTHOR]

This paper is the study of institutional and organizational aspects of the management system of a community based micro hydropower. It mainly focuses on the role of kinship as well as social capital for the sustainability of micro hydropower management. However, social capital has been analyzed as one of the fundamental sources of kinship organization. This study also emphasizes on the social transformation that is only possible with an effective social mobilization and reliable institutional sources. An organized form of management system for micro hydro is functioning continuously due to the consistent engagement of community, proper mobilization of groups/institutions and institutional guidance, where social and cultural substances are primarily embedded. Ethnographic fieldwork was the principal data collection method. Both direct and indirect participant observations were used to garner the substantial amount of data. In-depth nature of semistructured interviews on various social, structural and cultural aspects was used to conduct the key interviews. To make the representative units inclusive, twenty people were purposively selected for key informant interviews including male, female and from the various occupation status. The related structural issues as well as regarding the entire management system of micro hydropower were probed through the informal interviews and group discussions to enhance the ethnographic data. [ABSTRACT FROM AUTHOR]

Savonius hydrokinetic turbine is one of the prominent vertical axis turbines for tapping hydro potential available in flowing streams in rivers or canals. In spite of their simple design, Savonius turbines have the problem of poor performance. This study aims to enhance the performance of turbine through modification in the blade shape. Under the present study, geometrical parameters namely blade arc angle and blade shape factor are considered to modify the blade shape of Savonius hydrokinetic turbine. A commercial unsteady Reynolds-Averaged Navier-Stokes (URANS) solver in conjunction with realizable k-ε turbulence model has been used for numerical analysis. Using CFD analysis, blade arc angle and blade shape factor are optimized on the basis of coefficient of power. Fluid flow distributions found around the rotor has also been analyzed and discussed. Based on the present investigation, the maximum power coefficient value of 0.426 is obtained for blade arc angle of 150° and blade shape factor of 0.6 corresponding to TSR value of 0.9 at flow velocity of 2 m/s. [ABSTRACT FROM AUTHOR]

Pumps As Turbines (PATs) are a class of unconventional hydraulic turbines consisting of standard water pumps working in reverse mode as the prime mover. Such devices can be well suited for either in-pipe energy recovery or small-scale hydropower, but their practical application is hampered by the lack of comprehensive guidelines able to assist the designer in the determination of the optimal plant layout and the choice of equipment. In fact, the performances of a PAT will depend on factors such as its construction type, its size and the flow conditions under which the machine is expected to operate. Ultimately, the design of a PAT-based hydro scheme is a matter of trade-offs which are in most cases not trivial. An innovative software was developed in order to assist hydro designers and provide a visual aid when choosing between different layouts of the analyzed hydro scheme (e.g., more than one PAT in series/parallel, different shaft speeds), and has been applied to a real case study of energy recovery in a water network.

Feasibility study of the renewable energy resources is usually employed as a primary step in the design of Hybrid Renewable Energy System (HRES), to highlight the most potential sources and the best combinations obtained by using HOMER software. Thus, the main objective of this study is to identify the potential areas in Malaysia utilize solar, the wind and Micro Hydropower (MHP) sources. For this purpose, the results of a study accomplished by Ibrahim Hussein in 2010 are considered to obtain sites with the greatest hydropower potential in Malaysia. Then, a renewable energy resource assessment for these sites was performed to identify the sites that have the greatest solar, wind and hydropower potentials based on total Net Present Cost (NPC) comparison. Based on the historical data, a daily pattern emerged in electricity consumption among rural residents in Malaysia. The results of this study indicate Langkawi is the most potential region for the solar/wind combination by the significant difference with other regions (total NPC of 696,083 USD). After Langkawi, Tioman Islands has the second rank (total NPC of 818,931 USD), while villages in Tioman are the most appropriate sites for installing hybrid renewable energy system with the current specifications. In terms of the premiered locations for solar and hydropower potential, four sites at Lawas in Sarawak and Ranau in Sabah were identified as the greatest potential (total NPC of 354,000 USD). These findings demonstrate that Tioman Islands and Malaysian Borneo Island (Sabah and Sarawak) can be considered as the most attractive regions for the solar/wind/MHP and solar/MHP, respectively. [ABSTRACT FROM AUTHOR]

Rural electrification in developing countries is often hampered by major information gaps between local communities and urban centers, where technical expertise and funding are concentrated. The tool presented in this paper addresses these gaps to support the implementation of off-grid micro hydropower infrastructure. Specifically, we present a method to site, size and evaluate the potential for micro hydropower based on remote sensing data. The method improves on previous approaches by (i) incorporating the effect of hillslope topography on the optimal layout of the infrastructure, and (ii) accounting for the constraints imposed by streamflow variability and local electricity demand on the optimal size of the plants. An assessment of the method’s performance against 148 existing schemes indicates that it correctly identifies the most promising locations for hydropower in Nepal, but does not generally reproduce the specific design features of constructed plants, which are affected by site-specific constraints. We develop a proof-of-concept computer tool to explore the potential of webGIS technology to account for these constraints by collecting site-specific information from local users. [ABSTRACT FROM AUTHOR]

The modern layout and configuration of cities create power generation and storage possibilities through the urban water system. Surplus energy in water and wastewater networks has come to the researchers' attention for exploitation as micro hydropower (MHP). Also, the gravitational potential energy of stored water on highrises makes them a sustainable option for distributed energy storage as micro pumped-storage (MPS). Many studies have investigated technical aspects and estimated capacity of urban micro hydro systems (UMHS) in urban infrastructures. However, there is no systematic review of relevant literature to signify challenges and opportunities of different urban infrastructures as UMHS, from economic, technical, and environmental viewpoints. Therefore, this article applied a reference-by-reference method to provide a systematic assessment and concept review of UMHS, including the characteristics, challenges, and drivers of potential sites for MHP and MPS development. Examining the challenges of real case studies worldwide identifies economic feasibility and energy generation reliability as obstacles in developing MPS and MHP, respectively. Nevertheless, overlooked opportunities are recognised that may accelerate UMHS proliferation. UMHS synergies, such as water saving and peak-load shaving, are introduced as influential factors in the economic feasibility of the UMHS that can be achieved through deploying sustainable stormwater management strategies and considering real-time analysis in the volatile energy market. Furthermore, simulation-optimisation tools are concisely presented for both the design and operation stages. Finally, some future research directions are offered to clarify the role of urban UMHS in addressing water and energy issues as individual systems or integrated into other decentralised energy sources. [Display omitted] • Characteristics and drivers of potential sites for MPS and MHP are assessed. • Economic feasibility is recognised as the main limitation of implemented urban MPS. • Variable head and flow are the main challenges for MHP implementation in cities. • Water saving and load shifting are essential factors in MPS and MHP feasibility. [ABSTRACT FROM AUTHOR]

Exploitation of small hydropower sources requires the use of small turbines that combine efficiency and economy which can conveniently cater the power needs of rural and small communities. Cross-flow turbines are used widely in such micro hydropower plants due to their simple design, easier maintenance, low initial investment and modest efficiency. Also, because of their suitability under low heads, their efficient operation under a wide range of flow variations and ease of fabrication, cross-flow turbines have been extensively employed. The primary objective of this study is to numerically analyze the characteristics and the fluid flow in a cross-flow hydro turbine and to optimize its performance by geometrically modifying the several parameters. During the process, a base model was chosen, the design was modified simultaneously by varying the nozzle shape, changing the guide vane angle, varying the number of runner blades and simulations were carried out individually. Two phase (air & water at 25 °C), steady state with SST turbulence model was selected in the commercial CFD code ANSYS CFX 13.0 for the numerical simulation. The design parameters included 10 m head, 0.1 m 3 /s flow rate and 642 rpm rotational speed. The results obtained showed that the best efficiency obtained from the base nozzle was 63.67% which was geometrically modified that improved the turbine performance and the efficiency reached 76.60% (increase by 12.93%). Velocity distribution, pressure contours, output torque within the flow domain were also characterized. It was observed that the re-circulating flow region was reduced and also its pattern was varied. [ABSTRACT FROM AUTHOR]

There is great potential for the expansion of the small or micro scale hydropower network. Of the 43 thousand weirs in the UK there are only 500 consented hydro schemes. Planning applications for such schemes require a noise assessment. Noise evaluation of a proposed renewable scheme is often complicated by the turbine sites having distinct noise characteristics in the first instance, which are often caused by the weirs themselves. Three types of weir were studied: Broad Crest weirs were studied in detail; this is complimented by further studies in Flat V and Crump weirs. Flow data was collected for ten sites from the Environment Agency and the National Rivers Flow Archive to assess the collected Sound Pressure Level (SPL) and calculated Sound poWer Level (SWL) in relation to various river flows. Weir head height, width and meteorological data were also collected. It has been shown that the SPL data collection method used was the right choice, as the greatest amplitudes at the water impact interface at all weir types was recorded. SPL and SWL were found to be within a 36–82 dBz and 45–86 dBz range respectively for all weir types. These values can be used in computer simulations of sound propagation. The mean SPL and SWL difference between the weir types are 6.1 dBz and 6.3 dBz. Head height has the greatest effect on SPLs. Attenuation with distance was found to be similar to that of a free field line source in general. [ABSTRACT FROM AUTHOR]

Low efficiency is the main drawback of a Crossflow turbine, despite the turbine being an important low cost technology for micro hydropower generation. Poor flow profile has been mentioned by other Crossflow turbine performance investigators as one of the reasons for the underperformance. This paper has investigated, using numerical method, the flow profile in the turbine at best efficiency point and at operating conditions that are away from best efficiency point. Numerical method has also been used to calculate and predict the efficiency of the turbine. The flow physics in a Crossflow turbine runner is a two-phase with a movable free surface. Such flow physics is difficult to analyse even numerically. A procedure for numerical analysis was followed and ANSYS CFX® was used to solve the governing equations and to process the simulation results. Actual pictures of the flow were taken so as to compare the actual flow with the numerically determined flow profile. Turbine efficiency results from the previous performance evaluation experiment conducted on the model Crossflow turbine were compared with the numerically obtained efficiency results. It has been observed that the numerically obtained flow profile compare favorably with the actual flow pictures. The numerical analysis over-predicts the efficiency, especially for runner speeds that were more than the best efficiency point speed. Pockets of negative pressures and flow circulation have been observed in the flow profile. At constant head and valve opening, the velocity profile was found to vary more with runner speed than the pressure profile. The numerically obtained flow pattern showed positions where the flow gives maximum efficiency. Therefore, the study has shown that numerical method is a superior design tool for Crossflow turbines. [ABSTRACT FROM AUTHOR]

Micro hydropower station is one of the clean choices for off grid points with available hydropotential. The challenging in this type of energy production is the high capital cost of the installed capacity that is worse for low-head micro hydropower stations. Turbine price is the main problem for this type of energy production. In this research, a simple machine has been introduced instead of conventional propeller turbines. The key is using an axial pump as a propeller turbine. In the present research, a propeller pump was simulated as a turbine by numerical methods. Computational fluid dynamics (CFD) was adopted in the direct and reverse modes performance prediction of a single propeller pump. To give a more accurate CFD result, all domains within the machine control volume were modeled and hexahedral structured mesh was generated during CFD simulation. Complete performance curves of its pump and turbine modes were acquired. For verification of the numerical results, the machine has been tested in an established test ring. The results showed that a propeller pump could be easily run as a low-head turbine. In the next, the goal was to optimize the geometry of the blades of axial turbine runner which leads to maximum hydraulic efficiency by changing the design parameters of camber line in five sections of a blade. The efficiency of the initial geometry was improved by various objective functions and optimized geometry was obtained by genetic algorithm and artificial neural network to find the best efficiency of the turbine. The results showed that the efficiency is improved by more than 14%. Indeed the geometry has better performance in cavitation. [ABSTRACT FROM AUTHOR]

For a new concept of micro hydropower converter with positioned in gravitational vortex flow multistage turbine rotor with different values of specific speed has been modeled the velosity field of water flow through the conical channel in the absence of the turbine stages and was determined the flow structure by the computer simulation in the presence of the turbine stages. In the first case, the stream lines appear as helical spirals. The distributions of circular, radial and axial velocity components in the boundary layer, in the potential flow (zone of the free vortex) and in the forced vortex was determined. In the second case the structure of the water flow is changes with the formation of individual swirls in every area between the blades. The water velocity increases rapidly as proximity to the drain hole and strongly depends on sink and vortex strengths. [ABSTRACT FROM AUTHOR]

The theoretical and experimental study of a new type of micro hydropower converter is realized. The converter may be used for energy conversion of river water with small heads and coastal currents into mechanical work by local restructuring of water flow through a vertical conical channel in spiral form of gravitational vortex. In this vortex, at different heights of the conical channel, are positioned the rotor blades of the turbine with different values of specific speed. The characteristics of the gravitational vortex flow of water through the conical channel, the speed and the power characteristics of the micro hydropower converter were investigated and experimentally validated. [ABSTRACT FROM AUTHOR]