Small-scale Hydropower Plants Research Articles

Optimal Control of Cascade Hydro Plants as a Prosumer-Oriented Distributed Energy Depot

For political and economic reasons, renewable sources of energy have gained much importance in establishing a sustainable energy economy. By their very nature, however, their benefits depend on changeable weather conditions, and are unrelated to the generation and consumption patterns in industrial or home environments. This generation–dissipation disparity induces price fluctuations and threatens the stability of the supply system, yet can be alleviated by installing energy depots. While the classic methods of energy storage are hardly cost-effective, they may be supplemented, or replaced, by a distributed system of small-scale hydropower plants with ponds used as energy reservoirs. In this paper, following a rigorous mathematical argument, a dynamic model of a multi-cascade of hydropower plants is constructed, and a cost-optimal controller, with formally proven properties, is designed. On the one hand, it allows for an increase in the owners’ revenue by as much as 30% (compared to a free-flow state); on the other hand, it reduces the load fluctuation imposed on the grid and the legacy supply system. Moreover, the risk of floods and droughts downstream resulting from inappropriate use of the plants is averted.

Analysis of overcurrent protective relaying as minimum adopted fault protection for small-scale hydropower plants

Analysis of overcurrent protective relaying as minimum adopted fault protection for small-scale hydropower plants

Hydropowering sustainability transformation: policy frames on river use and restoration in Finland

Hydropower, as a flexible energy source, has sparked renewed interest in the ongoing decarbonisation of the society. Simultaneously, a wider transformation of the socio-ecological system towards more sustainable practices of energy production is required. Our paper draws from the sustainable transformation theory and the concepts of transformability, hydro-social cycle, and aquatic regime to study a system of water governance and regulation in Finland. Our case study data consists of 16 semi-structured interviews and 207 news articles from Yle national broadcast company. We studied the policy frames to reveal how the water governance actors understand, view and make sense of future river use and restoration, and how they utilise the frames for strategic purposes. Results demonstrate that the future river use and restoration were framed by four modes of thinking: 1) hydropower as a ‘cultural trauma’, 2) restoring rivers and dam removal after hydropower construction and operation to improve ecological flows in rivers, 3) improving the social acceptance of hydropower and dam removal, and 4) improving the efficiency of the hydropower regime as a flexible source of power. Our paper shows that to enable pathways for socio-ecological-technical transformations of aquatic ecosystems further scientific scrutiny should be focused on reconciliation of the interest of river restoration, recreational uses of aquatic environments and the flexible energy function of hydropower in energy transition. Removal of migration barriers and small-scale hydropower plants and building fishways and bypasses are part of this transformation. Furthermore, the river regulation needed to give impoundment facilities the flexibility, causes changes in water levels which may be a potential source of conflict between riparian residents and hydropower operators. Therefore, more emphasis should be placed on water governance that recognises the local dynamics and interactions within the social-ecological systems.

Perspectives of Small-Scale Hydropower Engineering in Ukraine

Every country takes care of energy independence and security by using different energy sources and remarkably increasing electricity production by renewable energy sources. Ukraine is not an exception, especially when the energy infrastructure is significantly damaged during the war and there is a lack of capacities in the energy system. Because of this, the Government of Ukraine is planning a number of measures to launch systems of domestic mini-power plants.Ukraine has favourable conditions for developing the network of small-scale hydropower plants. While the hydropower potential of the largest Ukrainian rivers is used, the potential of small rivers is used only partially. The small-scale hydropower plants were built during the last century very actively. In 1912 the first small-scale hydropower plant was built. From 1923 to 1960, there were 956 hydropower plants with different capacities from a few kW to a few MW. However, at the end of the 1980s, the interest in small hydro decreased because of the construction of the large hydropower plants in the river Dniester and Dnipro, heat and nuclear power plants. Only 49 plants were in operation. Since 1995 the interest in small hydro has increased again. Nowadays, there are about 150 hydropower plants in operation.The paper examines the past and present state of small hydropower plants and perspectives on their development in the future, both by building new or reconstructing existing power plants. The list of hydropower plants with a short description of possible reconstruction is given. Moreover, the way of reducing the negative influence of hydropower plants on the environment is studied. Taking into account the energy issues in Ukraine, the possibilities of off-grid operation of hydropower plants are considered.The importance of energy security was evident from the issues that Ukraine is recently facing. Building new and reconstructing old small-scale hydropower plants will help to ensure the energy security of other types of electricity generation.

Integration of battery and hydrogen energy storage systems with small-scale hydropower plants in off-grid local energy communities

The energy transition is pushing towards a considerable diffusion of local energy communities based on renewable energy systems and coupled with energy storage systems or energy vectors to provide independence from fossil fuels and limit carbon emissions. Indeed, the variable and intermittent nature of renewables make them inadequate to satisfy the end-users’ electricity demand throughout the whole day; thus, the study of energy storage systems, considering their seasonal storage behaviour (e.g., energy-power coupling, self-discharge loss, and minimum state of charge) is fundamental to guarantee the proper energy coverage. This work aims at identifying the off-grid operation of a local energy community powered by a 220 kW small-scale hydropower plant in the center of Italy using either a battery energy storage system or a hydrogen one with the Calliope framework. Results show that, whereas the hydrogen storage system is composed of a 137 kW electrolyser, a 41 kW fuel cell, and a storage of 5247 kgH2, a battery system storage system would have a capacity of 280 MWh. Even though the battery storage has a better round-trip efficiency, its self-discharge loss and minimum state of charge limitation involve a discharging phase with a steeper slope, thus requiring considerable economic investments because of the high energy-to-power ratio.

Downstream fish passage at small-scale hydropower plants: Turbine or bypass?

Introduction: Hydropower plants are frequently equipped with physical and behavioral fish protection barriers to prevent downstream moving fish from harmful turbine passage and to guide them to alternative bypasses. As not only diadromous but also potamodromous fish species migrate and inevitably have to pass hydropower plants, knowledge on corridor usage for a wide range of species is important to identify potential deficits and to improve bypass efficiency.Methods: In this study, the corridor usage of downstream moving fish (6,646 individuals from 42 species) was investigated at four small-scale hydropower plants with different concepts to prevent turbine entrainment and to bypass fish.Results: Despite existing bypasses and fine screens with 15 mm and 20 mm bar spacing to prevent turbine entrainment, a large proportion of fish (35%–88%) still passed the turbines. The mainly poor efficiency of the investigated bypasses was probably due to low discharge and unfavorable bypass location or detectability. The various bypass types were used by a different range of fish species and sizes due to species-specific behavior and differing fish communities between sites. The effectiveness of the investigated downstream corridors was positively correlated with the share of discharge.Discussion: To reduce the negative ecological impacts of hydropower plants on downstream moving fish, well-performing bypasses are required that consider not only current requirements regarding design, dimensioning and location, but also the site-specific fish community. Thus, bypasses should function for the widest possible range of species, which can be achieved through less selective bypass types such as full-depth bypasses, or a combination of different bypass systems. Moreover, less harmful turbine technologies and more effective fish protection systems need to be implemented, since fine screens with 15 mm and 20 mm bar spacing cannot prevent small-bodied fish species and juvenile fish <20 cm from turbine entrainment.

Energy loss mechanism due to tip leakage flow of axial flow pump as turbine under various operating conditions

Owing to its ability to handle large flows, an axial flow pump as turbine (PAT) can generate considerable amounts of electricity in small-scale hydropower plants. However, a PAT's efficiency can be hindered by tip leakage flow (TLF), namely, flow through the clearance between the impeller blade tip and shroud. Accordingly, this study investigates the influences of TLF on the PAT's energy performance through numerical simulations in which the entropy production method has been adopted. TLF and the associated tip leakage vortex (TLV) are found to both decrease the hydraulic efficiency and increase the flow rate; the shaft power output is also affected, especially near the machine's best efficiency point. The effect of TLF on the pressure distribution along the blade depends on the flow conditions, and the form of the TLV directly generated by TLF is affected by the flow incidence angle. The vorticity transport equation reveals that the vortex stretching term plays a dominant role in the spatial evolution of the TLV and has the greatest impact on the pressure distribution. Finally, different operating conditions lead to different energy loss mechanisms: turbulent dissipation is the main cause of energy loss, and high flow conditions are marked by an increase in TLF-dependent wall shear stress dissipation.

Streamflow maps for run-of-river hydropower developments in Japan

Japan recently introduced a feed-in tariff for small-scale hydropower plants, promoting the development of run-of-river hydropower plants in small-sized basins; however, appropriate implementation requires gauging station streamflow data at substantial costs and time (i.e., more than several years). Thus, in this study, we generated streamflow maps for small-sized basins (∼10 km2) throughout Japan using artificial neural networks (ANNs). Modeled output streamflow characteristics relied upon the input variables obtained from 176 basin characteristics and consisted of mean annual streamflow (QMEAN), daily streamflow indices in a flow duration curve (QD), and a water volume index for run-of-river hydropower energy production (WD95). We preliminarily investigated the impacts of selecting the input variables obtained from 176 basin characteristics on performances of the ANNs, which indicated that the ANNs showed high robustness for disinformative input variables and multicollinearity between input variables. Although QMEAN, high QD, and WD95 performed well, low QD were inadequate, possibly due to snowmelt contributions and small catchment sizes obstructing the detection of geological impacts. To accurately estimate the streamflow characteristics throughout Japan, we emphasize the importance of developing robust methods for correcting wind-induced precipitation undercatch and a spatial interpolation for precipitation in high-montane areas. Nevertheless, the ANNs for Japan proposed herein significantly outperformed a previous study exhibiting excellent global-scale ability. A map expressing run-of-river hydropower potential in small-sized basins was generated and closely corresponded to the spatial distribution and electrical output of existing hydropower plants. Furthermore, we demonstrated that the hydropower potential map reproduces the hydropower developments corresponding to the history of the electric power systems in Japan, which reflects its high reliability. Therefore, the hydropower potential map can greatly aid the exploration of optimal sites for hydropower developments.

Guiding migrating salmonid smolts: Experimentally assessing the performance of angled and inclined screens with varying gap widths

The loss of longitudinal connectivity in regulated rivers, both up- and downstream, has been detrimental for biodiversity worldwide. While progress has been made regarding upstream fish passage solutions, many questions remain unanswered regarding downstream passage alternatives. To address these knowledge gaps, we used Atlantic salmon (S. salar) smolts to experimentally assess the guidance efficiency and passage rates produced by several common screen-and-bypass fish guidance systems. Vertical screens with horizontally oriented bars extending across a turbine intake channel at a shallow angle (angled guidance screens), combined with a single, full-depth bypass entrance at their downstream end, were on average 20% more effective and produced passage rates that were 10 times higher than screens which extended perpendicularly across a turbine intake channel with vertically oriented bars that rose gradually towards the surface (inclined guidance screens) and with a bypass at the surface, on either side of the screen. Among inclined screens, gap width was negatively associated with guidance efficiencies and the smallest gap width (15 mm) exhibited a 41% greater guidance efficiency than the largest (30 mm). Among angled screens, performance was more closely linked to construction material as metal racks produced passage rates over three times faster than flexible Kevlar netting. Overall, passage through the guidance screens, and therefore into a tentative turbine intake area, was positively associated with gap width and was twice as prevalent among the inclined relative to angled guidance screens. Ultimately, an angled guidance screen with a 30 mm gap width produced the highest guidance efficiency and passage rates (a 30% improvement over the next best screen), while an inclined screen with a 30 mm gap width produced the lowest guidance efficiencies and passage rates. These results have implications for the suitability and performance of downstream fish passage solutions at both large- and small-scale hydropower plants where passage solutions are currently lacking or inadequate.

Willingness to Pay for Renewable Energy in Myanmar: Energy Source Preference

The increased use of renewable energy is imperative as a countermeasure to climate change. As with conventional electricity generation technologies, public acceptance of renewables is an important issue, and willingness to pay (WTP) is a widely used indicator to assess such public attitudes. Unfortunately, the literature to date mostly covers developed countries, with few WTP surveys in developing countries. Tackling climate change is an urgent issue for these developing countries; therefore, understanding of public attitudes toward renewables in developing countries is crucial. This study conducted the first survey on WTP for introducing renewable energy in Myanmar. Although Myanmar boasts abundant renewable energy resources, including solar power and biomass in addition to large-scale hydro plants, its resources are not being properly utilized to generate electricity. This study surveyed WTP for power generation by solar photovoltaics, small hydropower, and biomass facilities. The results showed the highest WTP for solar power (USD 1.92) with 10% share in the energy mix, and lower WTP for biomass and small hydropower electricity generations (USD 1.13 and USD 1.17, respectively). Careful public communication is thus crucial for expanding biomass and small-scale hydro power plants.

Progress for On-Grid Renewable Energy Systems: Identification of Sustainability Factors for Small-Scale Hydropower in Rwanda

In Rwanda, most small-scale hydropower systems are connected to the national grid to supply additional generation capacity. The Rwandan rivers are characterized by low flow-rates and a majority of plants are below 5 MW generation capacity. The purpose of this study is to provide a scientific overview of positive and negative factors affecting the sustainability of small-scale hydropower plants in Rwanda. Based on interviews, field observation, and secondary data for 17 plants, we found that the factors contributing to small-scale hydropower plant sustainability are; favorable regulations and policies supporting sale of electricity to the national grid, sufficient annual rainfall, and suitable topography for run-of-river hydropower plants construction. However, a decrease in river discharge during the dry season affects electricity production while the rainy season is characterized by high levels of sediment and soil erosion. This shortens turbine lifetime, causes unplanned outages, and increases maintenance costs. Further, there is a need to increase local expertise to reduce maintenance cost. Our analysis identifies environmental factors related to the amount and quality of water as the main current problem and potential future threat to the sustainability of small-scale hydropower. The findings are relevant for energy developers, scholars, and policy-makers in Rwanda and East Africa.

Overview of hydropower resources and development in Uganda

<abstract> <p>Even though hydropower plants are currently the most dominant source of electricity in Uganda, the rate of development of these resources for power generation remains low. Using a semi-systematic review approach, this paper seeks to understand why there is a slow rate of hydropower development in Uganda (challenges) and thereby provide potential solutions to these challenges. With current total capacity of about 1011 MW, findings indicate that there is a higher future prospect for hydropower generation in Uganda, with an estimated potential of over 4500 MW. In terms of number of projects, small-scale hydropower plants dominate power plants in Uganda, currently accounting for 19 out of 35 grid-connected power plants. However, with 855 MW installation capacity, large hydropower plants dominate the power generation plants landscape in Uganda. This study found that the challenges to hydropower development in this country are multi-dimensional including technical, economic, environmental, and social factors, and shows that the cross-cutting challenge is lack of human capacity that possess adequate skills to handle hydropower projects in the country. Furthermore, this study discussed practical solutions to address the identified problems facing hydro power in Uganda.</p> </abstract>

Habitat Use by Pseudochondrostoma duriense and Squalius carolitertii Downstream of a Small-Scale Hydropower Plant

Downstream of small-scale hydropower plants (SHPs), the intensity, frequency and persistence of hydropeaking events often cause an intolerable stress on fish of all life stages. Rapid increases in flow velocity result in fish avoiding unstable habitats and seeking refuge to reduce energy expenditure. To understand fish movements and the habitat use of native Iberian cyprinids in a high-gradient peaking river, 77 individuals were PIT tagged downstream of Bragado SHP in the North of Portugal. Tagged fish species included Pseudochondrostoma duriense and Squalius carolitertii. Fish positions were recorded manually on two different occasions: during hydropeaking events (HP) and without hydropeaking events (NHP). From the 77 tagged fish, we were able to record habitat use for 33 individuals (20 P. duriense and 13 S. carolitertii) in a total of 125 relocations. Fish species were distributed along the river reach with high density in the upstream area in the vicinity of the SHP tailrace, in particular during HP. Fish locations were associated with velocity for P. duriense and S. carolitertii. The latter tended to use faster flowing waters than P. duriense. Our findings on the habitat use in peaking rivers are a valuable tool to help in the selection and design of mitigation measures.

Overvoltage protection for grid-connected picohydro generation using photovoltaic inverters

Very small-scale hydropower plants are environmentally friendly and renewable resource-based innovative solutions. The interest in pico-hydro systems (up to 5 kW) has increased significantly from the first stand-alone applications, at remote sites, to the distributed generation, with the injection of generated energy into the grid. Recently, there have been advances in the grid connection of these systems using off-the-shelf components, namely photovoltaic inverters. Therefore, pico-hydro systems have gained an enormous potential in distributed generation, particularly in the context of microgrids. However, in situations of over-power, or whenever the generator is under no load, e.g. when the grid fails, there is a need for effective over-voltage protection, as in small wind turbines. This paper proposes two over-voltage protection circuits, designed to ensure the integration of pico-hydro turbines connected to the grid using conventional photovoltaic microinverters and string inverters, for power ranges of 300 W and some kW, respectively. Extensive tests were performed on an emulation platform and a workbench using these two different over-voltage protection circuits. One is designed to connect the generators of water wheels to the grid and the other to connect 1,500 W generators of water turbines. The experimental results demonstrated the performance of theproposed over-voltage protection circuits in four different situations. Both avoid irreversible damages of generators, photovoltaic microinverters and string inverters in the context of the above-described grid connection approach.

Potential energy exploitation in collective irrigation systems using pumps as turbines: A case study in Calabria (Southern Italy)

The development of efficient energy, water and environment systems is considered a fundamental key to satisfy the principles of cleaner production, energy security and circular economy. The present study aims at investigating the possible energy exploitation of the untapped hydraulic potential in collective irrigation systems by adopting pumps as turbines. These machines are not extensively used to produce electricity due to the lack of information in reverse operation mode and the low efficiency outside the best efficiency point. This study proposes new correlation rules to obtain more accurate performance of the pumps as turbines and introduces a novel methodology to select the proper hydraulic machines and define the optimal hydropower configuration. The proposed procedure based on a multi-variable optimisation has been applied to the whole collective irrigation networks of Calabria (Southern Italy). Specifically, the energy production, greenhouse gas emissions and investment costs of 114 potential small hydropower plants have been estimated. The results show that the adoption of pumps as turbines in small-scale hydropower plants is a viable, clean and cheap solution for an extensive use in collective irrigation systems. These machines lead to a noticeable decrease in the electro-mechanical costs (−74%) with only a slight reduction (−19%) in the total electric power compared to specific-site designed turbines. Furthermore, the proposed hydropower systems guarantee a significant fall in greenhouse gas emissions (larger than 8800 tons/year) with respect to the conventional Italian electric production. The generated electricity could be used to satisfy a larger share of electric demand coming from collective irrigation agencies and/or agricultural farms with significant improvements in their economic and environmental impact. Overall, the proposed methodology may represent a valid design tool for an extensive exploitation of hydropower sources in rural water systems, in an effort to enhance cleaner energy productions and integrated systems of energy, water and environment.

Experience and Possibilities of Effectively Utilizing the Energy Resources of the Dargom–Taligulyan Water and Energy Tract: Part II

This article examines the possibility of improving the energy efficiency of small advanced hydropower plants planned for construction on the operated multipurpose water–power tract in the Samarkand region. The variability of changes in the capacity generated monthly during the year and in the amounts of electricity generated by such small-scale hydropower plants (HPPs) as the Shaudar and Bagishamal power plants of the water-and-power path is numerically analyzed and found out to be 7.2 and 6.0 MW, respectively. A significant difference in the energy performance of the hydropower plants is discovered in their developed capacity and amount of electricity generated in winter–spring, summer, and autumn–winter. To equalize the fluctuations in the developed capacity produced by small hydropower plants, the expediency of using the energy of mountain-valley winds of the surface (up to 60–70 m) layers of the atmosphere in the zone of the water–power path is justified, including the possibility of creating integrated hydropower and wind power plants. This is based on a joint analysis of the regimes of watercourses and wind flows, which showed their complementarity during their minima and maxima. Numerical studies have allowed estimating the average monthly amount of electricity generated by 60, 250, 500, and 750 kW windmills of different types when installed at different heights above the Earth’s surface; the average daily runtime by months, the average monthly runtime duration and continuous downtime. The data from the numerical studies of the operation of the windmills have allowed justifying the expediency of creating energy–generation systems with mutually complementary operation modes of HPPs and WPPs with different variants of using windmills of particular capacity at different altitudes. The necessary area of the territory for placing windmills to create WPPs with a capacity commensurate with the capacity of advanced small hydropower plants is estimated.

Difference in biochemical markers in the gibel carp (Carassius auratus gibelio) upstream and downstream of the hydropower plant

However the physiological stress in aquatic organisms associated with hydropower plants (HPP) ecosystems has been previously investigated, no studies have so far assessed it on biochemical level. Therefore this study evaluated an oxidative stress and toxicity in the gibel carp Carassius auratus gibelio associated with a small-scale HPP in the West Ukraine. A battery of liver, brain and blood markers was evaluated individuals inhabiting upstream and downstream of the dam of the small-scale Kasperivtci HPP (KHPP; an installed capacity of 7.5 MW), and from a reference site. Number of alterations were noted in fish from the KHPP impoundment facility including signs of oxidative stress (a decrease in superoxide dismutase (SOD) activity and an increase in protein carbonyls) and cytotoxicity (an increase in micronucleated erythrocytes and caspase-3 activity). No changes in DNA fragmentation in hepatocytes or brain cholinesterase activity were detected. As demonstrated by the integral stress index, fish associated with downstream of the dam revealed the greatest alterations reflected by the combined oppression of antioxidant system (SOD, catalase) and pro-oxidants (thiobarbituric acid reactive substances and oxyradicals), low concentration of metallothioneins, but high cathepsin D activity (as markers of lysosomal dysfunction and autophagy) and increased vitellogenin concentration in males (indicating an endocrine disruption). The study highlights that fish inhabiting ecosystems associated with HPP, particularly downstream of the dam, may face additional stresses with long-term effects yet to be evaluated.

Influence of hydrologically based environmental flow methods on flow alteration and energy production in a run-of-river hydropower plant

Increasing demand for renewable energy has led to a massive expansion of the small-scale hydropower plants and particularly those of run-of-river type. Meanwhile, the awareness concerning river conservation and restoration is being continually increasing. This study focuses on the assessment of environmental flows releases and energy production considering eight hydrological based environmental flows methods. The main goal of this study is to propose a practical approach that allows for quick estimation of the environmental flows releases and alteration due to water diversion for energy production, in the case of run-of-river hydropower plants. For this purpose, the indicators of hydrological alteration approach was applied to characterise flow alteration, and three economic metrics were used to assess the impact on energy production. Downstream Diversion Index was proposed to characterise the degree of water diversion due to energy production. Also, five new simplified indexes derived from indicators of hydrologic alteration approach were proposed to simplify flow alteration characterisation. The results of this study showed that a minor reduction of energy production could significantly improve environmental flows releases for the riverine ecosystem needs. Particularly, proportional dynamic approaches maximise energy production and imposes relatively less flow alteration. Also, it was concluded that following flow parameters: frequency, timing, duration and rates, can be maintained close to the natural regime without necessarily reducing the energy production by choosing the right environmental flows method. Finally, the methodology developed in this study can be a useful decision-making tool to help water managers, by including other relevant information also (i.e., biological, water supply, irrigation, and social) to choose the most appropriate method for the environmental flows determination in the case of run-of-river hydropower plants.

Living in a bubble: potential gains from flexible water management policies

ABSTRACTWe study Swedish implementation of the European Union’s Water Framework Directive, and compare the current implementation strategy with more flexible ‘bubble’ schemes, where measures can be traded among various locations within the same river system to reach the overall environmental target. Two different Swedish river systems, the Mörrum system with small-scale hydropower plants, and the Ångerman system with larger plants, are studied. We find that the environmental benefits that current policies are likely to accomplish could be achieved at well under half the cost in the Mörrum system, and at less than a tenth of the cost in the Ångerman system.

Computational Fluid Dynamic Predictions on Effects of Screw Number on Performance of Single Blade Archimedes Screw Turbine

One of the alternative solutions to reduce the impact of electricity crisis in Aceh and other isolated areas in Indonesia is by the construction of small-scale hydro power plants that can work efficiently on the heads lower than 10 meters. One suitable type of turbine applied to the head below 10 meters is the Archimedes screw turbine. Due to the lack of information about the application of low head power plants, resulting in applications of this type of turbine is still less in Indonesia. This paper examined the appropriate turbine model. Before experimental turbine testing, turbines were designed theoretically first and then analyzed numerically. The flow velocity and pressure patterns within the turbine were analyzed using ANSYS CFD (Computational Fluid Dynamic) software under design conditions for 7, 9 and 11 screw numbers for single blade turbine. Based on the results of pressure analysis, speed and turbulent kinetic energy, it found that turbine performance using 11 blades is better among the three turbines. However, the highest average speed was obtained on the turbine using 7 screws, which maximum pressure obtained on a turbine 7 screws of 1406 Pa, on 9 screws on plane 1301 Pa and at 11 screws of 1175 Pa. Based on the results of the analysis, it showed that the smaller the distance between the channel and turbine blades, the results were more efficient due to the absence of wasted streams. Therefore, the flow pressure in the inlet position all directly leaded to the tip off the blade to produce a momentum.