Electrification System Research Articles

Techno-economic analysis of solar energy system for electrification of rural school in Southern Ethiopia

To provide rural communities with low-cost electricity, innovative off-grid renewable energy producing techniques have emerged. The International Energy Agency estimates that around 45% of Ethiopia’s total population have access to electricity. Nearly 85% of Ethiopia’s urban population has access to public electricity, but this figure is only 29% for the rural population. This study examines the feasibility of using combined photovoltaic (PV)/diesel/battery systems to power a remote rural school in southern Ethiopia. The performance of various hybrid systems was assessed using techno-economic and environmental analyses, and the optimal solution was chosen using the Hybrid Optimization Model for Electric Renewable (HOMER) analytic tool. The evaluation criteria include net present cost (NPC), cost of energy (COE) and emissions. The results indicate that PV/DG/battery hybrid energy system (HES) with a 7.5 kW PV, 7.3 kW DG, 6.60 kW converter, and 11 units of batteries (case I) is the most feasible, optimized, cost-effective and environmentally friendly system among the systems considered. This system has a Net Present Cost (NPC) of $32,019 and a Cost of Energy (COE) of $0.254/kWh, as computed using current equipment values. The optimized system is also environmentally benign, emitting 793 kg of carbon dioxide per year, about 91% less than the PV/diesel combination (worst case IV). Furthermore, sensitivity analysis was performed to examine the impacts of altering factors such as solar radiation, fuel price, and battery minimum state of charge (SOCmin) on system cost and performance. We believe that the information given in this paper will shed light on the current state and future prospects for renewable energy deployment in Ethiopia, and also show that, if policymakers create the necessary investment environment, such projects can be a viable alternative to rural electrification.

Techno-Economic Analysis of Grid-Connected Hybrid Renewable Energy System for Remote Areas Electrification Using Homer Pro

Techno-Economic Analysis of Grid-Connected Hybrid Renewable Energy System for Remote Areas Electrification Using Homer Pro

Performance assessment of a hybrid complementary power system for sustainable electrification: A case study

This paper looks at an islanded complementary power system in Sierra Leone’s South-eastern region. It presents a method for assessing or evaluating the performance of an existing complementary hybrid energy system (Bo-Kenema power network) in an urban environment, taking seasonal variability into consideration. The proposed method attempts to assess the feasibility of establishing either a new hybrid system without current sources or a hybrid system that includes both existing and new sources. A comprehensive techno-economic-environmental optimization analysis was carried out in which 13 scenarios were evaluated and compared. With a net present cost (NPC) of $50.4 million (M) and a cost of energy (COE) of $0.211/kWh, Case 1 (Solar photovoltaics (PV)/generator 1 (G1)/generator 2 (G2)/generator 3 (G3)/battery/hydro/converter) was found to be the most cost-effective and sustainable scenario. The sensitivity analysis performed on Case 1 (optimum scenario) revealed that the total system cost was heavily reliant on turbine efficiency, PV and battery capital prices. Furthermore, adding two extra high-efficiency turbines (75%) to the optimum scenario eliminated the PV component and reduced the COE and NPC by 38.9% (from $0.211/kWh to $0.129/kWh) and 39.1% (from $50.4M to $30.7M) respectively, while increasing CO2 emissions by 49.9%. This elimination led to a change in the configuration of Case 1 (G1/G2/G3/hydro). The preference of the governing authorities determines whether the previous or later optimal design is to be implemented. By implementing this strategy, the optimum scenario can provide cost-effective and long-term electricity for the selected region.

Optimisation of a Renewable Energy System for Rural Electrification

Anaerobic digestion systems have been implemented on a number of rural farms all over the world as manure management solutions. Electricity and heating are also provided by means of such systems. In these systems, biomass waste is anaerobically digested to produce biogas, which is then burned in a boiler or an engine generator set to generate heat or power, depending on the system. The size and method of operation of a cattle waste-to-energy conversion system that would yield the highest revenue for a specific number of cattle are calculated in this study. An optimization method for Tabu Search is applied. The best answer is determined after several top-notch ones have been produced. The efficiency of a system for converting cattle waste into energy will help to increase rural electricity in Uganda.

HISTORICAL ROOTS OF THE ENERGY INDUSTRY IN UZBEKISTAN

The power industry has a huge impact on the development of electrification systems. This article provides information on the construction of hydropower plants in Uzbekistan, the establishment of electricity generation and power sources, electrification of the country.

Multi-objective multi-verse optimization of renewable energy sources-based micro-grid system: Real case

Hybrid micro-grid systems (HMGS) are small scale power system where the energy sources are installed to supply local customers. These systems may be considered as promising energy solution to meet the increased in energy demand and traditional sources depletion. Cost of electricity, system reliability, and environmental impacts of the system are three design criteria that must be considered in obtaining the accurate parameters of hybrid renewable energy system components. In this paper, hybrid micro-grid renewable energy system includes photovoltaic system, (PV) wind energy system, (WES) battery bank, (BB) and conventional diesel generator (DG) are proposed to meet the energy requirements in remote area, located in Red Sea called city of Bernice, Egypt, at 23° 54′ 31″ N, 35° 28′ 21″ E. Optimization of Cost of Electricity (COE), Renewable Factor (RF), and Loss of Power Supply Probability (LPSP) are main objective of the designing process of the hybrid system considered as the objective functions. Then, Multi-objective multi-verse optimization (MOMVO) algorithm is used with considering two scenarios, the first one is renewable sources and the second is renewable/diesel energy source. All the possible HMGS configurations namely: PV/battery, wind/battery, PV/wind/battery and PV/battery/diesel, wind/battery/diesel, PV/wind/battery/diesel are studied and analyzed. Moreover, one year hourly meteorological weather data for case study are recorded. Reverse osmosis desalination (ROD) is considered in conjunction with the residential load. The proposed power management strategy is used to manage the system operation when supplying the load. A linear fuzzy membership function is used for purpose of decision making. The simulation results show that MOMVO produces appropriate components size and the PV/wind/battery/diesel is the optimum configuration with values of COE = 0.2720$/KWh, LPSP = 0.1397, and RF = 92.37% at w 1 = 0.5, w 2 = 0.3, and w 3 = 0.2. Sensitivity analysis is performed to show the effect of changing system parameters on the objective functions. It is also shown that the techno-economic feasibility of using HMGS for rural electrification systems and enhance energy access.

Sizing Algorithm for a Photovoltaic System along an Urban Railway Network towards Net Zero Emission

A reliable transportation system is essential for the development of a community. Especially in urban transportation, rail transportation is a faster, more comfortable way to travel for the commuters. These benefits can be valued further when the rail transportation system is with zero emissions. Electric trains can be considered a zero-emission transportation method. However, a rail transportation system operates with net-zero emissions when electricity is generated from zero-emission-based sources. Photovoltaic systems have already been integrated into railway stations and spare land owned by railways to achieve net-zero emissions. Furthermore, medium-voltage DC network and microgrid concepts have been proposed to incorporate more renewable energy sources into railway electrification systems. However, the energy generated from those systems is not enough to realise net-zero emissions, as the power requirements of an urban railway electrification system are high. Accordingly, this article investigates the possibility of implementing a photovoltaic system along the railway tracks to meet the energy demands of an urban railway electrification system so that net-zero emissions can be achieved. Other significant advantages of the proposed photovoltaic system are lower feeder losses due to distributed photovoltaic systems integrated into the railway electrification system, lower conversion losses due to the direct integration of the photovoltaic system into the railway electrification system, and the nonrequirement of additional space to install the photovoltaic system. In this paper, a photovoltaic system capacity sizing algorithm is proposed and presented by considering a railway electrification system, the daily schedule of trains, and historical photovoltaic weather data. This proposed photovoltaic system capacity sizing algorithm was evaluated considering a section of the urban railway network of Sri Lanka and a three-year, 2017-2020, photovoltaic weather data. The results indicated that the potential for photovoltaic generation by installing photovoltaic systems along a railway track is much higher than the requirement, and it is possible to meet the required train scheduling options with proper sizing. Furthermore, in the three-year analysis, it is possible to achieve 90% of the energy required for the railway electrification system with effective train scheduling methods.

Techno-economic-environmental and sociological study of a microgrid for the electrification of difficult un-electrified isolated villages

The need for electrification of un-electrified locations is usually met through the grid extension. However, it is not a cost-effective solution for difficult geographical regions. This gap of grid extension can be met through distributed generation, which can be renewable or non-renewable generation systems. However, non-renewable generation systems have a greenhouse effect, which has a hazardous effect on the environment and the native community. This study proposes a microgrid with the most suitable combination of the renewable energy system (RES) for electrification of un-electrified locations in difficult geographical conditions such as in the northeastern parts of India. Four RESs, with standalone and hybrid configurations, are compared for finding the optimal configuration of power plants. Moreover, the social impact of different power plants, carbon emission reduction by their establishment, and grid extension options are studied for the overall acceptance of the power plant by the native community and economic viability for investors.

Techno-economics of Hybrid System Electrification of Roll-on/Roll-off Vessels in the Philippines

The shipping industry is vital for archipelagic countries like the Philippines as they allow transport between islands, but it is a notable contributor of greenhouse gases. In this work, a framework for analyzing the techno-economic potential of hybridizing a sea vessel with solar photovoltaics, lithium-ion batteries, and diesel generators was presented. The roll on/roll off vessel Filipinas Ozamis was considered as a case study due to its commercial use. A 3D model of the roll-on/roll-off vessel was used to measure the ship’s dimensions. The load profile of the vessel was estimated from the ship’s dimensions, operational profile, route, and speed according to the MarineTraffic AIS database. Afterwards, diesel-only and hybrid energy systems were sized in HOMER Pro to power the electrified ship while minimizing its costs and noting the available space on the sea vessel. Lastly, the profitability of the hybrid energy system was determined. The hybrid system was marked with increased capital costs, but the fuel consumption and CO2 emissions were 18.50 % and 27.90 % lower than those of the diesel-only system, respectively. The hybrid system also had lower generation costs and 23.64 % higher net present value than the diesel-only system. This framework can be used in the absence of measured load profiles and can be extended to other sea vessels to conduct a national techno-economic assessment of hybridizing the country’s maritime industry.

The challenges of community-based solar energy interventions: Lessons from two Rwandan Refugee Camps

The paper presents evidence from the performance assessment of two solar energy interventions. Specifically, an evidence base was built around two community co-conceived standalone photovoltaic-battery systems, which were deployed in two refugee camps in Rwanda. We found that for both installations (a micro-grid and a community hall electrification system) energy consumption levels were low, showing that sizeable energy consumption gaps can still develop when co-conceived interventions are deployed. The consumption gap led to low performance ratios (33% and 25% respectively for the micro-grid and community hall system). To guide further work and improve the sustainability of community interventions, we draw a number of design principles for future energy interventions in similar contexts. To deliver sustainable energy transitions for refugees, there needs to be a move towards co-creating community interventions that promote self-governance to position communities as users, maintainers and suppliers of energy services, throughout an intervention's lifetime.

Simulation-Based Optimization of Hybrid Renewable Energy System for Off-grid Rural Electrification

There is a need to develop an optimization tool that can be applied in the feasibility study of a hybrid renewable energy system to find the optimal capacity of different renewable energy resources and support the decision makers in their performance investigation. A multi-objective function which minimizes the Levelized Cost of Energy (LCOE) and Loss of Load Probability Index (LLPI) but maximizes the novel Energy Match Ratio (EMR) was formulated. Simulation-based optimization method combined with ε-constraint technique was developed to solve the multi-objective optimization problem. In the study, ten-year hourly electrical load demand, using the end-use model, is estimated for the communities. The performance of the developed algorithm was evaluated and validated using Hybrid Optimization Model for Electric Renewables (HOMER®) optimization software. The developed algorithm minimized the LCOE by 6.27% and LLPI by 167% when compared with the values of LCOE ($0.444/kWh) and LLPI (0.000880) obtained from the HOMER® optimization tool. Also, the LCOE with the proposed approach was calculated at $0.417/kWh, which is lower than the $0.444/kWh obtained from HOMER®. From environmental perspective, it is found that while 141,370.66 kg of CO2 is saved in the base year, 183,206.51 kg of CO2 is saved in the ninth year.The study concluded that the approach is computationally efficient and performed better than HOMER® for this particular problem.The proposed approach could be adopted for carrying out feasibility studies and design of HRES for Off-Grid electrification, especially in the rural areas where access to the grid electricity is limited

Simulation-Based Optimization of Hybrid Renewable Energy System for Off-grid Rural Electrification

There is a need to develop an optimization tool that can be applied in the feasibility study of a hybrid renewable energy system to find the optimal capacity of different renewable energy resources and support the decision makers in their performance investigation. A multi-objective function which minimizes the Levelized Cost of Energy (LCOE) and Loss of Load Probability Index (LLPI) but maximizes the novel Energy Match Ratio (EMR) was formulated. Simulation-based optimization method combined with ε-constraint technique was developed to solve the multi-objective optimization problem. In the study, ten-year hourly electrical load demand, using the end-use model, is estimated for the communities. The performance of the developed algorithm was evaluated and validated using Hybrid Optimization Model for Electric Renewables (HOMER®) optimization software. The developed algorithm minimized the LCOE by 6.27% and LLPI by 167% when compared with the values of LCOE ($0.444/kWh) and LLPI (0.000880) obtained from the HOMER® optimization tool. Also, the LCOE with the proposed approach was calculated at $0.417/kWh, which is lower than the $0.444/kWh obtained from HOMER®. From environmental perspective, it is found that while 141,370.66 kg of CO2 is saved in the base year, 183,206.51 kg of CO2 is saved in the ninth year.The study concluded that the approach is computationally efficient and performed better than HOMER® for this particular problem.The proposed approach could be adopted for carrying out feasibility studies and design of HRES for Off-Grid electrification, especially in the rural areas where access to the grid electricity is limited

실시간 시뮬레이터를 활용한 철도차량 PMSM 제어시스템의 시계열 기반 안정도 추정

This paper deals with numerical analysis method for system stability, which is applied to the mathematical model of permanent magnet synchronous motor for railway vehicle as one of the application of real-time digital simulation. Specifically, this study deals with bifurcation numerical analysis, one of analytic method to study nonlinear dynamics of a system, for system design or its inspection technique of the system model. XPPAUT is used to analyze the electrical motion of this complex system, so it can introduce theoretical approach to design real-time computing environment based on OPAL-RT for electrification system parts of railroad vehicle model. Within the real-time simulation framework, the paper also provides time-series based system stability estimation by performing statistical processes for auto-regressive model construction. The proposed approach can reduplicate verification process by screen studying of the model for improvement during real-time simulation or further hardware-in-the-loop test system.

Analysis of Hybrid Grid-Connected Renewable Power Generation for Sustainable Electricity Supply in Sierra Leone

The provision of electricity in a reliable and sustainable manner in provincial towns and villages in the small West Africa state of Sierra Leone requires the adoption of appropriate technologies. The rapid increase in electricity demand has generated great interest in how to tackle a possible long-lasting energy deficiency in the country. This paper aims at analyzing the techno-economic feasibility of a hybrid renewable energy system (HRES) for the sustainable rural electrification of Lungi Town, Port Loko District, Sierra Leone. Optimization, economic, reliability, and sustainability analyses were carried out using a genetic algorithm (GA), with the main objectives of minimizing the loss of power supply probability (LPSP) and cost of energy (COE). Three different case scenarios were configured, using a diesel generator (DG), wind/PV/DG/battery, and wind/PV/battery. Various combinations of these case scenarios were compared to determine which option was the most economically viable. In order to determine the case scenario with the lowest LPSP and COE, the operations and maintenance costs of the three cases were calculated. Using only DG for case one, the operations and maintenance cost amounted to USD 1050,348.12/year. The operation and maintenance cost for case two, which included wind/PV/DG/battery, was found to be USD 561,674.06/year. The operations and maintenance cost for case three, which included wind/PV/battery, was found to be USD 36,000/year. In standalone microgrids, however, the use of renewable energy sources is not reliable due to the uncertainty of renewable energy sources. Consequently, the simulation results show that the wind/PV/DG/battery-based HRES is the most cost-effective, reliable, and sustainable for the specific location in comparison to the current traditional method of electricity generation. Since there is abundant solar radiation with substantial wind speeds across the country, this HRES can be applied in most rural and remote areas in place of the current diesel generators (DGs) that are widely deployed in the country.

Sizing and economic analysis of stand-alone hybrid photovoltaic-wind system for rural electrification: A case study Lundu, Sarawak

Energy Consumption has been increasing at an alarming rate due to the growing energy need. More and more non-renewable sources are harvested to fulfill the energy demand resulting in and rising environmental health issues. However, harvesting Solar and Wind energy is considered as the best alternative in generating energy as these resources are renewable. Hybrid Renewable Energy System (HRES) has been grabbed the attention recently, as it involves with renewable, environmentally friendly sources to generate energy. The limitation of single Renewable Energy (RE) system is overcome by systems such as HRES. Even though it has been introduced different sizing and optimization techniques, due to the lack of system function, it had posed issues in calculating the optimized cost of a hybrid system considering the solar, wind resources and load demand as the optimization of the system cannot be predicted accurately. The aim of this research was to obtain optimization of a Hybrid PV-wind system in term of sizing and cost over the 20 years of the period of interest. The simulation of the PV-Wind Hybrid system using MATLAB for the verification purpose. This work includes detailed calculation using the Life Cycle Cost method for identifying all possible combinations. The combination of eleven Solar Panels, one Wind Turbine and nine Batteries was identified as the optimal Combination with LCC of RM 221,329.97 and has been verified using simulation results. Lastly, a sensitivity test was carried out using the exiting results of verified by the simulation to identify the most deterministic system in affecting LCC of the Hybrid system. Further, total Cost distribution for the Optimized hybrid PV-Wind system was conducted and identified that 50% of system cost was contributed by the Wind turbine. Determination of LCC, was done as a combination of Component and Operation costs. It was identified that Replacement cost contributed the highest while Wind turbine showed the highest Operation cost from the system cost. Thus, this work was included with the sensitivity test assuming 10% price increment for each component and it was concluded that price changes in Wind turbine results the greatest difference in LCC while further verified with the results of the simulation.

Stationary Hybrid Renewable Energy Systems for Railway Electrification: A Review

This article provides an overview of modern technologies and implemented projects in the field of renewable energy systems for the electrification of railway transport. In the first part, the relevance of the use of renewable energy on the railways is discussed. Various types of power-generating systems in railway stations and platforms along the track, as well as in separate areas, are considered. The focus is on wind and solar energy conversion systems. The second part is devoted to the analysis of various types of energy storage devices used in projects for the electrification of railway transport since the energy storage system is one of the key elements in a hybrid renewable energy system. Systems with kinetic storage, electrochemical storage batteries, supercapacitors, hydrogen energy storage are considered. Particular attention is paid to technologies for accumulating and converting hydrogen into electrical energy, as well as hybrid systems that combine several types of storage devices with different ranges of charge/discharge rates. A comparative analysis of various hybrid electric power plant configurations, depending on the functions they perform in the electrification systems of railway transport, has been carried out.

Improving the Load Estimation Process in the Design of Rural Electrification Systems

The design of reliable and sustainable rural electrification systems relies on accurate prediction of the electrical load. This paper evaluates the current methods for load estimation and proposes an improved approach for load estimation for off-grid unelectrified rural communities that yields more accurate estimates. Improved accuracy is mainly due to better modelling of the influence of customer habits and gender on the estimated current and future load using the Markov chain process. A program was developed using MATLAB software to generate load profiles. The results show that gender considerations have a significant impact on load profiles and that the Markov chain process can suitably be used to determine year-to-year load profiles by incorporating the effect of changes in customer habits on the estimated load. The results from the case study on energy consumption in rural community households showed an increase in average daily consumption when gender was considered during load estimation. The peak consumption when gender was considered was about 50% higher than the value for when gender was not considered.

Design and Feasibility Analysis of Hybrid Energy-Based Electric Vehicle Charging Station

Mobility has been changing precipitously in recent years. With the increasingnumber of electric vehicles (EV), travel-sharing continues to grow, and ulti-mately, autonomous vehicles (AV) move into municipal fleets. These changesrequire a new, distributed, digitalised energy system, maintenance, and grow-ing electrification in transportation. This paper proposes the designing of anElectric Vehicle Charging Station (EVCS) by using hybrid energy sourcessuch as solar PV, wind, and diesel generator. The proposed system is math-ematically modelled and designed using the Hybrid Optimization Model forMultiple Energy Resources (HOMER). The system is analysed and assessedin both autonomous mode and grid-connected mode of operation. The opti-mum sizing, energy yields of the system in each case is elaborated, and thebest configuration is found for design. The variations in Levelized Cost Ofthe Energy (LCOE), Net Present Cost (NPC), initial cost, and operating costof the various configuration are presented. From the results, it is observed thatthe grid-connected EVCS is more economical than the autonomous EVCS.Further, a sensitivity analysis of the EVCS is also performed.

Bidirectional Battery Interface in Standalone Solar PV System for Electrification in Rural Areas

In a standalone photovoltaic (PV) system, a bidirectional DC converter (BDC) is needed to prevent the battery from damage caused by DC bus voltage variation. In this paper, BDC was applied in a standalone solar PV system to interface the battery with a DC bus in a standalone PV system. Therefore, its bidirectional power capability was focused on improving save battery operation while maintaining high power quality delivery. A non-isolated, buck and boost topology for the BDC configuration was used to interface the battery with the DC bus. PID controller-based control strategy was chosen for easy implementation, high reliability, and high dynamic performance. A simulation was conducted using MATLAB Simulink program. The simulation results show that the implementation of the BDC controller can maintain the DC bus voltage to 100 V, have high efficiency at 99.18% in boost mode and 99.48% in buck mode. To prevent the battery from overcharging condition, the BDC stops the charging process and then works as a voltage regulator to maintain the DC bus voltage at reference value.

Identification of the best topology of delta configured three phase induction generator for distributed generation through experimental investigations

AbstractResearch on Self –excited induction generator (SEIG) brings a lot of attentions in the last three decades as a promising solution in distributed generation systems with low cost investment. There are two important fixations to attend in the operation of SEIG based systems, a) excitation and b) voltage regulation. Many procedures are reported regarding selection of excitation capacitance in the literature, based on state-state analysis, dynamic modeling, empirical formulas and machine parameters which involve various levels of complexity in findings. Moreover, the voltage regulation is the main challenge in implementation of SEIG based isolated systems. To address this problem, many power electronic-based schemes are proposed in the literature and but these solutions have few demerits importantly that additional cost of equipment and troubles due to failure of protection schemes. In particular, the installation of SEIG takes place at small scale in kW range in remote/rural communities which should not face such shortcomings. Further in case of off-grid systems, the maximum loading is fixed based on connected rating of the generator. This paper presents the various methods to find excitation capacitance and illustrates an experimental investigation on different possible reactive power compensation methods of delta connected SEIG and aimed to identify a simple method for terminal voltage control without power electronics. In this experimental work, the prime-mover of the generator is a constant speed turbine, which is the emulation of a micro/pico hydro turbine. From the results, it is found that a simple delta connected excitation and delta configured reactive power compensation limits voltage regulation within ±6% while maintaining the frequency of ±1%, which make feasible of the operation successfully in remote electrification systems.