Search Results (20)

Off-grid renewable energy systems have become a cost-effective way to supply electricity in remote rural areas, contributing to achieving universal energy access as mandated by Sustainable Development Goal 7 (SDG7). However, benefits are often compromised by limitations in the financial and technical capacity and capabilities of rural beneficiaries to operate and maintain the technology, raising concerns about the cost-effectiveness of investment in the systems. This study examines the non-economic social benefits of providing electricity through off-grid renewable systems and whether these benefits justify investment in the efforts and costs borne by rural communities. Using the case study of the community-managed Kalilang micro-hydro power plant (MHPP) operating on Sumba Island, Indonesia, we estimate the value of non-market benefits of off-grid renewable electricity in rural Indonesia. By applying a mixed-methods approach, this research qualitatively identified perceived non-market benefits through 16 key informant interviews and subsequently employed contingent valuation (CV) with 105 households to estimate their willingness-to-pay (WTP) for these benefits. The results suggest that off-grid renewable projects remain socially viable even when direct economic returns are lacking. Inclusion of these social values into project evaluation and appraisals is needed to better reflect the contribution of off-grid renewable energy systems to community well-being. Full article

This work proposes a new method to refill fuel cell electric vehicle hydrogen tanks from a storage system in hydrogen refueling stations. The new method uses the storage tanks in cascade to supply hydrogen to the refueling station dispensers. This method reduces the hydrogen compressor power requirement and the energy consumption for refilling the vehicle tank; therefore, the proposed alternative design for hydrogen refueling stations is feasible and compatible with low-intensity renewable energy sources like solar photovoltaic, wind farms, or micro-hydro plants. Additionally, the cascade method supplies higher pressure to the dispenser throughout the day, thus reducing the refueling time for specific vehicle driving ranges. The simulation shows that the energy saving using the cascade method achieves 9% to 45%, depending on the vehicle attendance. The hydrogen refueling station design supports a daily vehicle attendance of 9 to 36 with a complete refueling process coverage. The carried-out simulation proves that the vehicle tank achieves the maximum attainable pressure of 700 bars with a storage system of six tanks. The data analysis shows that the daily hourly hydrogen demand follows a sinusoidal function, providing a practical tool to predict the hydrogen demand for any vehicle attendance, allowing the planners and station designers to resize the elements to fulfill the new requirements. The proposed system is also applicable to hydrogen ICE vehicles. Full article

The voltage control of synchronous generators, particularly under varying load conditions, remains a significant and complex challenge in the field of engineering. Although various control methods have been implemented for automatic voltage regulator (AVR) systems to control the terminal voltage of synchronous generators, the PID-based control method continues to be one of the most basic and widely used approaches. Determining the optimal values for the Kp, Ki, and Kd values is essential to ensuring efficient and rapid performance in a PID controller. This study presents PLC-based PID controller tuning using an adaptive artificial bee colony–fuzzy logic (aABC-FL) approach for voltage control in a micro-hydro power plant installed as an experimental setup. The real-time control and monitoring of the system was conducted using an S7-1200 programmable logic controller (PLC) integrated with a totally integrated automation (TIA) portal interface and a SCADA screen. The aABC-Fuzzy design was developed using the MATLAB/Simulink platform, with PLC-MATLAB communication established through OPC UA and the KEPServerEX interface. The results obtained from experiments conducted under different load conditions showed that the proposed aABC-FL PID significantly minimized settling time and overshoot compared to the classical PLC-PID. Additionally, the proposed method not only provided a good dynamic response but also proved to be robust and reliable for real physical AVR systems. Full article

The control system for a micro-hydropower plant using an Archimedes screw turbine is the focus of this work. Three control systems were implemented based on a Barreda micro-hydropower plant (Spain) currently in operation: an optimal water level control ($OWLC$) system, a maximum power point monitoring ($MPPT$) system, and a water level control ($WLC$) system. The comparison was made using several assessment indicators: electricity production, micro-hydropower plant efficiency, and gearbox fatigue. The electricity production is similar in the $OWLC$ and $MPPT$ systems (energy gain $+0.5\%$) and significantly lower in the $WLC$ system (energy gain $-12\%$). The efficiency of the micro-hydro plant is similar in the $OWLC$ and $MPPT$ systems (average efficiency gain $+0.9\%$) and significantly lower in the $WLC$ system (average efficiency gain $-15\%$). The mechanical stress on the gearbox is similar in the $OWLC$ and $WLC$ systems and significantly higher in the $MPPT$ system. It can be concluded that the $OWLC$ system performs better as concerns the three assessment indicators used, followed by the $MPPT$ system. The $WLC$ system is not recommended for use, due to its low electricity production and low efficiency of the micro-hydropower plant. Full article

Hydrogen is considered the primary energy source of the future. The best use of hydrogen is in microgrids that have renewable energy sources (RES). These sources have a small impact on the environment when it comes to carbon dioxide (CO₂) emissions and a power generation cost close to that of conventional power plants. Therefore, it is important to study the impact on the environment and the power cost. The proposed microgrid comprises loads, RESs (micro-hydro and photovoltaic power plants), a hydrogen storage tank, an electric battery and fuel cell vehicles. The power cost and CO₂ emissions are calculated and compared for various scenarios, including the four seasons of the year, compared with the work of other researchers. The purpose of this paper is to continuously supply the loads and vehicles. The results show that the microgrid sources and hydrogen storage can supply consumers during the spring and summer. For winter and autumn, the power grid and steam reforming of natural gas must be used to cover the demand. The highest power costs and CO₂ emissions are for winter, while the lowest are for spring. The power cost increases during winter between 20:00 and 21:00 by 336%. The CO₂ emissions increase during winter by 8020%. Full article

This paper proposes an optimal solution for the design of a hybrid power system that will supply a remote fishpond in eastern Serbia. In terms of structure, this off-grid system should be a hydro-photovoltaic-diesel-converter-battery setup. The optimization objectives are to minimize total net present cost (NPC) and greenhouse gas (GHG) emissions and to maximize total annual electricity generation based on the modification of hydro-turbine performance. This study considers the following three cases of a hydro-turbine with fixed propeller blades: having fixed guide vanes, for the annual average flow rate-Case 1; having adjustable guide vanes, for smaller flow rates-Case 2 and having adjustable guide vanes, for higher flow rates-Case 3. The optimization is performed using HOMER Pro v. 3.16.2 software. The results show that the total NPC, levelized cost of energy (COE) and GHG emissions in Case 3 are 16.6%, 16.8% and 13.1% lower than in Case 1, and 8.1%, 8% and 11.7% lower than in Case 2, respectively. It is also found that the total annual electricity generation and power output from the entire system in Case 3 are 33.3% and 1.2% higher than in Case 1, and 11.9% higher and not different than in Case 2, respectively. Full article

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

This paper proposed a standalone solar/wind/micro-hydro hybrid power generation system to electrify Ethiopian remote areas that are far from the national utility grid. The aim is that it will lead to the development of renewable energy sources, using a hybrid optimization model for energy renewables (HOMER) as an optimization and sensitivity tool and MATLAB as a design tool. The system uses 100% renewable energy. This system incorporated solar photo-voltaic (PV), wind turbines, micro-hydro systems, and battery systems. The net present cost of the system is $4,377,731, incorporating capital depreciation and levelized operation and maintenance costs. During the hybrid energy system’s lifetime, the cost of a grid extension power supply is $22.185 million, which is nearly $17,808,000 more than the cost of the proposed standalone system. So, developing solar/wind/micro-hydro hybrid power generation will save $17,808,000 versus extending the national utility grid. As a result of a thorough examination of renewable energy resources, standalone solar, wind, and micro-hydro hybrid power generation is a technically and economically viable option for the case study area of Maji town. Full article

This paper presents an energy-management strategy based on a recently introduced Political Optimizer (PO) for a microgrid installation at Wroclaw University of Science and Technology. The aim of the study is to check the effectiveness of two recently introduced meta-heuristic algorithms at power-system-operations planning. The optimization algorithms were compared with other conventional meta-heuristics wherein performance tests were carried out by minimizing costs in an IEEE 30-bus system. The best performing algorithm was then used to minimize the Levelized Cost of Energy (LCOE) in a microgrid consisting of renewable energy sources such as solar PV panels, a micro-hydro power plant, a fuel cell with a hydrogen storage tank and a Li-ion storage unit. Full article

Nowadays, microgrids (MGs) play a crucial role in modern power systems due to possibility of integrating renewable energies into grid-connected or islanded power systems. The Load Frequency Control (LFC) is an issue of paramount importance to ensure MGs reliable and safe operation. Specifically, in AC MGs, primary frequency control of each energy source can be guaranteed in order to integrate other energy sources. This paper proposes a micro-hydro frequency control scheme, combining the control of a reduced dump load and the nozzle flow control of Pelton turbines operating in autonomous regime. Some works have reported the integration of dump load and flow control methods, but they did not reduce the dump load value and adjust the nozzle flow linearly to the power value demanded by users, causing the inefficient use of water. Simulation results were obtained in Matlab^®/Simulink^® using models obtained from previous research and proven by means of experimental studies. The simulation of the proposed scheme shows that the frequency control in this plant is done in correspondence with the Cuban NC62-04 norm of power energy quality. In addition, it is possible to increase energy efficiency by reducing the value of the resistive dump load by up to 7.5% in a case study. The validation result shows a 60% reduction of overshoot and settling time of frequency temporal behavior of the autonomous micro-hydro. Full article

In this research paper, the relationship between a crossflow turbine and propeller turbine size changes and the pond size in a free vortex power generation system was investigated. This relationship can be written in the form of a new mathematical equation using the principles of the response surface methodology (RSM) method. This study aimed to compare the efficiency of a crossflow turbine and propeller turbine to enhance a micro power plant from free vortex. The pond size in a micro power plant from free vortex was 1 m in diameter and 0.5 m in height with a 0.2 m outlet drain at the bottom. All turbines were tested at different water flowrates of 0.2, 0.3, 0.4, 0.5, and 0.6 m³/s to identify the rpm, water head, voltage, and electric current to access the waterpower, power output, and overall efficiency. At a 0.02 m³/s water flowrate, the crossflow turbine had greater overall efficiency than the propeller turbine, reaching 9.09% efficiency. From the comparison of the results of the two turbines used in the 0.5 m high cylinder-shaped generator pond, the turbine type, turbine size (height and diameter), number of blades, and water flowrate are key factors that affect the overall efficiency. The crossflow turbine can achieve greater efficiency than the propeller turbine in this generator system. Full article

The Archimedes/Archimedean screw generator (ASG) is a fish-friendly hydropower technology that could operate under a wide range of flow heads and flow rates and generate power from almost any flow, even wastewater. The simplicity and low maintenance requirements and costs make ASGs suitable even for remote or developing areas. However, there are no general and easy-to-use guidelines for designing Archimedes screw power plants. Therefore, this study addresses this important concern by offering a simple method for quick rough estimations of the number and geometry of Archimedes screws in considering the installation site properties, river flow characteristics, and technical considerations. Moreover, it updates the newest analytical method of designing ASGs by introducing an easier graphical approach that not only covers standard designs but also simplifies custom designs. Besides, a list of currently installed and operating industrial multi-Archimedes screw hydropower plants are provided to review and explore the common design properties between different manufacturers. On top of that, this study helps to improve one of the biggest burdens of small projects, the unscalable initial investigation costs, by enabling everyone to evaluate the possibilities of a green and renewable Archimedes screw hydropower generation where a flow is available. Full article

The sustainable development of micro-hydropower (MHP) plants is a challenge for rural electrification in developing countries, especially in Indonesia, which has diverse ethnic groups, cultures, and traditions in several isolated locations due to its complex terrain. The uniqueness of a social situation in a location can affect the sustainable electrification development. This study aimed to assess the sustainable development of MHP plants in the Kasepuhan Ciptagelar, which has unique traditions and cultural characteristics. The assessment was conducted using the sustainable development indicator (SDI) method, the Ilskog method, which can include social, economic, environmental, technical, and institutional dimensions. Data were collected through field investigations and qualitative dialogs to understand the culture and ways of thinking. The results of the Ilskog method analysis revealed that the environmental dimensions had the highest scores, whereas economic dimensions had the lowest scores, indicating that the cultural background of the Kasepuhan Ciptagelar impacted the SDI scores. This was attributable to the decision of Kasepuhan’s traditional leader, which strengthened the community commitment to renewable energy use. However, the cultural background adversely impacted monetary income to sustain MHP plants. This study proposed that community innovation and microcredit availability could improve productive activities, resulting in better economic conditions to sustain MHP plants. Full article

The production of electric energy from rivers by using mini, as well as micro hydroelectric power plants, is a very promising solution, especially in rural and isolated areas. Numerous waterways in Croatia and their hydrological and hydrogeological diversity present an opportunity, but also a challenge, for the construction of hydroelectric power plants. Due to the complexity of the water courses’ hydrology, as well as hydrogeological characteristics, it is very hard to determine an appropriate flow pattern (amount), which will be used as an input value for the sizing of hydroelectric power plants. Such analysis will be provided for real case studies in Croatia with special regard to present geological media—media with intergranular porosity (Bednja River), karst media (Gornja Dobra River), and flysch media (Mirna River). Considering different geological media increases the possibility of using the presented methodology on other locations in Croatia, as well in the world. It has been shown that the analyzed rivers definitely have potential for electric energy production, regarding the potential and kinetic river energy. The presented analysis is scientifically original, but also shows the procedure for the determination of the hydro-energy potential of the rivers, as well as for the sizing on the hydropower plants. Hydrology and hydrogeology analyses rounds out the usual hydro-energy analysis, which is in most cases based on basic statistical parameter analysis. Full article

Micro-hydro power plants (μHPPs) are a major energy source in grid-isolated zones because they do not require reservoirs and dams to be built. μHPPs operate in a standalone mode, but a continuously varying load generates voltage unbalances and frequency fluctuations which can cause long-term damage to plant components. One method of frequency regulation is the use of alternating current-alternating current (AC-AC) converters as an electronic load controller (ELC). The disadvantage of AC-AC converters is reactive power consumption with the associated decrease in both the power factor and the capacity of the alternator to deliver current. To avoid this disadvantage, we proposed two rectifier topologies combined with symmetrical switching. However, the performance of the frequency regulation loop with each topology remains unknown. Therefore, the objective of this work was to evaluate the performance of the frequency regulation loop when each topology, with a symmetrical switching form, was inserted. A MATLAB^® model was implemented to simulate the frequency loop. The results from a μHPP case study in a small Cuban rural community called ‘Los Gallegos’ showed that the performance of the frequency regulation loop using the proposed topologies satisfied the standard frequency regulation and increased both the power factor and current delivery capabilities of the alternator. Full article