Proposed Hybrid Energy System Research Articles

Risk-constrained optimal operation of fuel cell/photovoltaic/battery/grid hybrid energy system using downside risk constraints method

Residential consumers have electrical and thermal loads. Therefore they can be utilized hybrid thermal and electrical energy systems to procure their required energy. In the proposed system, in order to supply residential loads, a hybrid energy system (HES) is proposed which consists of photovoltaic/solid oxide fuel cell/thermal and electrical storages/boiler. Also, the uncertain parameters such as thermal and electrical loads, electricity market price, and solar irradiation are considered in the stochastic formulation. Uncertain parameters can be led to financial risks in the system operation. In order to measure imposed risks, in this paper, a novel risk management method called downside risk constraints method is used to model the financial risks imposed from the uncertain parameters. According to obtained results, the operator of the hybrid energy system by utilization of the downside risk constraints method has obtained a strategy that is scenario independent. In other words, the downside risk constraints method by minimizing the imposed risks introduced a zero-risk strategy which operation cost would not increase by changing the scenario. Results are shown that system operators by paying 1.3% more expected cost ($ 40.22 instead of $ 39.69), can make its operation independent of the scenario. Also, risk-based operational strategies of the proposed hybrid energy system are reported in the results as graphical results. The proposed risk-measurement operation problem of the designed hybrid energy system is formulated as a mixed-integer linear programming (MILP) model and modeled by GAMS software using CPLEX solver.

Capacity optimization of grid connected solar/fuel cell energy system using hybrid ABC-PSO algorithm

Hybrid renewable based power generation has emerged as a major breakthrough in electrical power system due to their capability of providing competitive and carbon free electricity to the consumer. This paper presents techno-economic analysis of a grid connected solar photovoltaic-fuel cell based hybrid energy system to supply the electrical load demands of a small shopping complex located at the University campus in India. The proposed system has been designed by considering the cost of energy purchase and sold to the utility grid and further ensuring the smooth power flow management between elements of the system and the utility grid. A simplified mathematical modeling of the proposed hybrid energy system, including power and hydrogen management has been presented to access the potential of hydrogen based energy systems. Component sizing to optimize the net present cost of the proposed system has been performed employing three meta-heuristic algorithms, i.e., artificial bee colony, particle swarm optimization and a hybrid of both. The experimental results obtained from three algorithms have been compared in terms of cost effectiveness of the system. The hybrid system has been designed to cater the total electricity demand of 135 MWh/yr of a small community center. It has emerged from the simulation results that the total electricity demand could be met with a 106 kW solar photovoltaic, 8 kW fuel cell, 45 kW electrolyzer and a 150 kg of hydrogen tank. The proposed grid connected system has 30 kW grid purchase and 25 kW grid sale capacities, respectively. In this paper, grid sale and purchase capacities have been considered as a decision variable along with other system component sizing. Loss of power supply probability is minimized along with objective function i.e., levelized cost of electricity (LCOE) using the exterior penalty method. It is evident from the results that the proposed system is economically viable with a LCOE of 0.104 $/kWh. It has emerged from the results that the proposed hybrid energy system may be helpful to promote hydrogen and solar based energy system to reduce the reliance on the overburden grid, particularly, in developing countries.

Simulation and Management Strategy of Energy Flow in Hybrid System

This paper presents a control algorithm based on energy dispatch strategy in a remote area of Niger in West Africa region. . The system is a micro grid equipped with solar panels, conventional source and energy storage units. The hybrid energy management system presented is meant for rural and remote area power supply. The hybrid system configuration focuses on providing an uninterrupted power supply the maximum loads energy demand. This approach can improve the living conditions through the increase the economy and easiness of access to energy through a reasonable cost from an economic point of view to avoid over-sizing of production sources. The optimal configuration and model details of the proposed hybrid energy system has been described. The aim of this paper was to improve the design, operation and control requirement of a hybrid system in a specific area of Dakoro in Niger. The proposed control energy flow management strategy has been brought out by performing experimental studies on a laboratory prototype.

A systematic decision-making approach for planning and assessment of hybrid renewable energy-based microgrid with techno-economic optimization: A case study on an urban community in Egypt

This paper proposes a systematic and integrative decision-making approach for efficient planning and assessment of hybrid renewable energy-based microgrid (HRE-MG) systems. The approach is combined with an extensive techno-economic optimization analysis. The proposed methodology is validated with an actual case study on an urban city in Egypt, with the developed HRE-MG comprising solar, wind, diesel, and fuel cell energies. Different hybridization scenarios are modeled, evaluated and compared to obtain the most practicable solution with minimum cost and emission impact. The obtained results reveal that solar, wind, fuel cell show optimal configuration plan that yields a minimum net present and energy costs. Also, it achieves a significant reduction in carbon gases and increases system renewable fraction compared to other scenarios. Further, the reliability of the proposed hybrid energy system is examined under loss of power supply probability concept. A sensitivity analysis is then conducted to verify the model accuracy and examine the cost performance of the designed system concerning uncertain parameters.

Techno-economic design and evaluation of hybrid energy systems for residential communities: Case study of Jubail industrial city

Abstract A total of around 300 TWh of electricity was consumed in Saudi Arabia in the year 2018, a per capita consumption of 9100 kWh. Almost all of this electricity is generated by non-renewable sources of energy. This study explores the prospective application of hybrid energy systems PV/Wind/Diesel and PV/Wind with battery storage for three residential compounds in Jubail Industrial City, an eastern coastal city in Saudi Arabia. Technical and economic viability of various hybrid energy system designs is weighed and an optimum system is adopted using HOMER software. This hybrid system is optimized to meet the electrical load demand of three residential compounds with one, two, and three-bedroom apartments with a load demand of 11,160; 4865; and 3288 kWh/day and a peak load of 685, 463 and 270 kW. The minimum COE was found to be 0.183, 0.224 and 0.244 US$/kWh, for PV/Wind/Diesel/Battery option for compound 1, 2 and 3 respectively. The average total NPC was around 9.9, 5.6, and 3.9 million US$, respectively. For options with 100% RE penetration, minimum COE was found to be 0.25 US$/kWh, for PV/Wind/Battery option for all three compounds. This optimum system will also save 2800 tons of carbon-dioxide emissions every year. This proposed hybrid energy system can be applied to other regions of the world with similar weather conditions.

Hybrid microgrid for microfinance institutions in rural areas – A field demonstration in West Africa

We present a hybrid energy microgrid optimization model for a microbank in a remote rural residential area. The model is based on the use of renewable (wind turbines & solar photovoltaic (PV)) and conventional (gasoline generators) energy sources and battery storage systems. We conducted a detailed assessment of a typical microbank’s load, residential loads and energy resources in a village called Ajasse-Ipo in Kwara State, Nigeria. We performed the modeling of a hybrid microgrid system, followed by an economic analysis and sensitivity analysis to optimize the hybrid system design. We performed simulations based on the energy resources available (solar PV, wind, gasoline generator & battery energy storage system) to satisfy the energy demands of the microbank, while the excess energy was supplied to meet the demand of the community loads, i.e. water pumping machine and rural home lighting. The results obtained showed that the hybrid system comprising the solar PV/battery/diesel was most techno-economically viable with a Net Present Cost (NPC) and Cost of Energy (COE) of $468,914 and 0.667$/kWh, respectively. Comparing these results with those obtained using analytical methods, the solar PV, battery and converter sizes obtained were slightly higher than the optimal system configurations as produced by HOMER. The proposed hybrid energy system also allowed to achieve almost 50% reductions in CO2, CO, unburned hydrocarbons, particulate matter, SO2 & NO2. The system can be applicable for other rural regions in the developing countries with similar environmental conditions.

Carbon-neutral hybrid energy systems with deep water source cooling, biomass heating, and geothermal heat and power

This article addresses the optimal design of carbon-neutral hybrid energy system with deep water source cooling, biomass heating, and geothermal heat and power. A novel superstructure of the proposed hybrid energy system comprised of an enhanced geothermal system, a torrefied biomass-based combustion system, and a deep water source cooling system with conventional chillers as auxiliaries, is developed. Based on the superstructure of the proposed hybrid energy system, we develop a multi-period optimization model to minimize a fractional metric, the levelized cost. Because the main product of the hybrid energy system is heat, the levelized cost is expressed as levelized cost of heat, with other byproducts indirectly incorporated by using credits. The resulting nonconvex mixed-integer nonlinear fractional programming problem is efficiently solved by using a tailored optimization algorithm. Two case studies based on Cornell’s campus in Ithaca, New York are presented to quantify the effect of different electric power sources on the technoeconomic objective, as well as the life cycle greenhouse gas emissions. The first case study considers electric power from natural gas, while a carbon-neutral electric power supply based on renewable geothermal energy is envisioned in the second case study. Results show that switching the electric power supply from natural gas to geothermal energy could reduce the greenhouse gas emissions by 24.5%, while only increasing the levelized cost of heat by 5.6%. The carbon footprint for both case studies are promisingly low, compared with numerous existing heat generation technologies. Through sensitivity analysis, the project lifetime is identified as the most influential input parameter.

An improved genetic algorithm-based optimal sizing of solar photovoltaic/wind turbine generator/diesel generator/battery connected hybrid energy systems for standalone applications

This paper proposes an improved GA-based new approach for the optimal design of hybrid energy systems comprises of solar PV, wind, diesel generator and battery connected systems for supplying the electrical power. The proposed system uses the meteorological data of wind speed, wind velocities and solar radiations, which were collected from NASA website. Optimisation of hybrid energy system includes minimisation of total cost, net present cost, loss of power system probability, reduced greenhouse gas emissions, cost of energy, annualised system cost to make the system more economically for the domestic house hold applications. The optimisation of results can be achieved by using improved Genetic Algorithm (GA), which uses the variables such as wind turbine capacity, PV array ratings, number of battery banks, diesel generator rated power, system initialisation cost and operation and maintenance cost were considered as the input chromosomes for the algorithm. A suitable improved GA programme has been formulated using MATLAB toolbox with the objective function of minimising the total/net present cost of the proposed hybrid energy system for electrifying the rural areas in standalone applications.

Intelligent power supply management of an autonomous hybrid energy generator

ABSTRACTThis work deals with the optimization of an hybrid energy system used to supply an isolated site. The proposed system combines a wind turbine, a photovoltaic panel, a diesel generator and a battery bank to electrify atypical home. An energy cost-effectiveness approach is adopted in accordance with meteorological data, time profile of energy consumption, and the cost of different alternative systems. A variety of performances is obtained through simulations within the Homer Pro environment. The selection of an optimal combination is based on the maximum integration of renewable energy in the suggested system with a minimum of gas emission. According to the obtained results, the overall cost of the selected installation is about 72,900 €, with 0.415€ the unit cost of a kWh electric energy provided with a contribution of renewable energy of around 86%. Simulations show a technical and financial benefits of the different configurations obtained to supply the target site. To control the proposed hybrid energy system, a supervision algorithm is developed and implemented on TMS320F28027 DSP platform. The proposed energy system aims to take advantages of renewable energy sources and shift to conventional sources only when necessary in order to ensure source autonomy and service continuity.

Design of an Optimal off-grid Hybrid Energy System for a Rural Community

This paper presents an optimized off-grid PV-diesel generator-battery hybrid energy system for application in an un-electrified rural community and further outlines a procedure for designing such an economical and technically feasible hybrid system. The hybrid optimization model for multiple energy resources (HOMER) software was utilized for simulation and analysis. The criteria of minimum net present cost of system, low CO 2 emissions and zero electric load rejection was applied while considering technical issues of PV array, inverter coordination and PV capacity penetration level. For the case study system used, the obtained optimized hybrid energy system configuration is as follows: 68kW PV plant; 40kW Diesel plant; 45.4kW Inverter; and 80kWh battery unit. The proposed hybrid energy system is capable of producing 157685kWh of electricity annually at a levelized cost of energy of 0.55 $/kWh while emitting 51,000 kg of CO 2 yearly. To avoid self-shading of the PV array, an appropriate inter-row distance was determined. The total quantity of PV modules and the electrical configuration of the PV array is presented. Keywords : Hybrid energy system, Net present cost, Optimal sizing and Photovoltaic

Optimal design of hybrid energy system based on persuasive policies for renewable resources in Iran (case study: University of Bojnord)

Governments all over the world are tending to accelerate the process of replacing fossil based energies with renewable energy sources through developing incentive or punitive policies. In Iran, various incentive and punitive guidelines are regulated to persuade governmental and nongovernmental organizations to use renewable energy resources. In this paper, optimal planning and sizing of distributed renewable energy resources for governmental organizations in Iran, under persuasive policies, is proposed. This design includes a techno-economic analysis on the basis of total Net Present Cost (NPC) to obtain the optimal configuration of the hybrid energy system for governmental institutes among all possible combinations of distributed diesel generators (consisting of internal combustion engines with diesel fuel) as well as renewable energy resources such as wind energy conversion systems and solar photovoltaics. In order to evaluate the economic and technical aspects of the persuasive policies for governmental institutes in Iran, an optimal hybrid energy system is designed to provide for the energy consumption of the University of Bojnord. The proposed hybrid energy system consists of 100 kW photovoltaic panels, 20 kW wind turbines, a 10 kW diesel generator, and 10 one kW h batteries. The total NPC of the system is estimated to be 1.04 $M. In addition, a sensitivity analysis is carried out to investigate the impact of economic indicators on the design. The results show that the University of Bojnord would benefit from investing in the proposed design after six years.

Power Management of a Stand-Alone Hybrid (Wind/Solar/Battery) Energy System: An Experimental Investigation

In this manuscript, a hybrid wind/solar/battery energy system is proposed for a stand-alone applications. Wind-solar energy sources are used as power generation source in the proposed hybrid energy system (HES), whereas battery is used as energy storing system in order to manage the power flow among various power generation sources and energy storing system. Power management control strategy is also presented for a suggested hybrid system. Through the real load demand and practical weather data (proposed area is Jamshoro, Sindh Pakistan), the system performance is verified under different situations. It is observed that the hybrid system produces maximum power in summer season as compared to other seasons throughout the year. Moreover, the power generated from wind and solar energy contributes 77.88% and 22.12%, respectively. However, it is clearly observed that the HES is cost effective and can be used in remotely rural areas which are isolated from power grid. In future work, the HES can be integrated with the power grid in order to meet the load demand during shortage of power.

Optimization of PV/WIND/DIESEL Hybrid Power System in HOMER for Rural Electrification

A large proportion of the world's population lives in remote rural areas that are geographically isolated and sparsely populated. The present study is based on modeling, computer simulation and optimization of hybrid power generation system in the rural area in Muqdadiyah district of Diyala state, Iraq. Two renewable resources, namely, solar photovoltaic (PV) and wind turbine (WT) are considered. The HOMER software is used to study and design the proposed hybrid energy system model. Based on simulation results, it has been found that renewable energy sources perhaps replace the conventional energy sources and would be a feasible solution for the generation of electric power at remote locations with a reasonable investment. The hybrid power system solution to electrify the selected area resulted in a least-cost combination of the hybrid power system that can meet the demand in a dependable manner at a cost about ($0.321/kWh). If the wind resources in the study area at the lower stage, it's not economically viable for a wind turbine to generate the electricity.

Techno-economic viability of a hybrid wind and solar power system for electrification of a commercial building in Shiraz, Iran

In this paper, techno-economic viability of a hybrid Wind/PV system with a battery and inverter was performed using the HOMER international optimization model. A commercial building in Shiraz, Iran was selected as a case study to analyze the feasibility study of installing the proposed hybrid Wind/PV system. Before the optimization process, different key parameters such as the monthly wind and solar resource, monthly and daily electrical load consumption, economic constraints such as interest rate and project lifetime, the components features such as the battery or inverters sizes and costs and other related information were collected and imported into HOMER. The optimization results suggested that the most efficient and economical hybrid energy system is a combination of 9 kW photovoltaic panel, 1 wind turbine (10 kW), 5 batteries and 5 kW converter. The total net present cost (NPC) and the cost of energy (COE) for this system were estimated to be $89,884 and $0.619/kWh. The final results of the study concluded that the employment of the proposed hybrid energy system for electrification of the studied commercial building in Shiraz is highly recommended.

Hybrid energy fuel cell based system for household applications in a Mediterranean climate

In this paper, a specific hybrid energy system was proposed for household applications. The hybrid energy system was assembled from a HT-PEM fuel cell stack supplied by hydrogen via a steam reformer, where finally the majority of produced electricity is used to drive a modified split heat pump system with heat recovery (that is enabled via standard modified accumulation boilers). The system is able to produce both high and low temperature heat output (in the form of hot water), cooling thermal output and electricity. Performance analysis was conducted and the specific hybrid energy system showed high value for overall energy efficiency, for the specific case examined it reached 250%. Levelized Cost of Energy (LCOE) analysis was also carried out and the proposed hybrid energy system’s cost is expected to be between 0.09€/kWh and 0.16€/kWh, which is certainly competitive with the current retail electricity price for households on the EU market. Additionally, the system also has environmental benefits in relation to reduced CO2 emissions, as estimated CO2 emissions from the proposed hybrid energy system are expected to be at around 9.0gCO2/kWh or 2.6 times less than the emissions released from the utilization of grid electricity.

Optimum design of an off-grid hybrid renewable energy system for an office building

Although much attention has been paid to the utilization of hybrid renewable energy systems for either commercial buildings or residential ones, rare studies dealt with the application of off-grid hybrid renewable energy systems for commercial buildings. This paper presents a comprehensive study on the techno-economic performance of a stand-alone hybrid photovoltaic (PV)-wind-battery system for an office building located in Tehran, Iran. The Hybrid Optimization Model for Electric Renewables model was used to investigate the optimal design options and the techno-economic viability of the hybrid renewable energy system installed in that building. The proposed hybrid system based on renewable resources was designed to electrify the restrooms of the building. An optimal system configuration was chosen based on the total net present cost (NPC) and cost of energy (COE). The simulation results demonstrated that the optimum structure for the hybrid system for the primary load demand of 5.6 kW h per day, consists of 3 kW PV modules, 1 kW wind turbine, 1 kW inverter, and sixteen 200 A h batteries. The total NPC of such a system was estimated to be $21 132, while the COE was $1.543 per kW h. In addition, the proposed hybrid energy system could provide 2733 kW h additional electricity to the office building. Furthermore, in the last part of this research, a sensitivity analysis for different parameters such as primary load, wind speed, global solar radiation, interest rate, total NPC, cost of electricity, number of batteries and total electrical production was performed to demonstrate and elaborate the effect of each decision variable on the configuration of the optimum hybrid system. It became clear that two hybrid system configurations, i.e., PV-Wind-Battery and PV-Battery systems, are suggested as the most economical and feasible alternatives and have wide range of usage for different load demand values. Additionally based on the change in the initial design parameters such as wind speed, global solar radiation, load demand, and the real interest rate, a comparison between these two hybrid systems in terms of the total NPC, COE, electrical production, excess electricity, and grid extension distance has been made to investigate the effect of each decision variable on the optimal combination and the techno-economic viability of the hybrid renewable energy system.

Performance Analysis of Solar-Wind-Diesel-Battery Hybrid Energy System for KLIA Sepang Station of Malaysia

A large number of populations of the world live in rural or remote areas those are geographically isolated. Power supply and uninterrupted fuel transportation to produce electrical power for these remote areas poses a great challenge. Using renewable energy in hybrid energy system might be a pathway to solve this problem. Malaysia is a large hilly land with the gift of renewable energy resources. There is a good chance to utilize these renewable resources to produce electrical power and to limit the dependency on the fossil fuel as well as reduce the carbon emissions. In this perspective, a research is carried out to analyze the performance of a solar-wind-diesel-battery hybrid energy system for a remote area named “KLIA Sepang station” in the state of Selangor, Malaysia. In this study, a 56 kW hybrid energy system has been proposed that is capable to support more than 50 households and 6 shops in that area. Real time field data of solar radiation and wind speed is used for the simulation and optimization of operations using “Homer” renewable energy software. The proposed system can reduce CO2 emission by about 16 tons per year compared to diesel generator only. In the same time the Cost of energy (COE) of the optimized system is USD 5.126/kWh.The proposed hybrid energy system might be applicable for other parts of the world where the climate conditions are similar.

Optimal Power Management Controller for a Stand-alone Solar PV/Wind/Battery Hybrid Energy System

In this article, a DC-linked stand-alone solar photovoltaic (PV)/wind/battery hybrid energy system is proposed. The wind and PV generation systems are the main power generation sources, the battery system is used as backup generation, and the water heater acts as a dump load to utilize any excess power available with source. The simulation model of the hybrid system has been developed in MATLAB/Simulink platform. Simulation studies have been carried out to verify the system performance under different scenarios using the practical load profile and real weather data collected at National Institute of Technology Calicut campus. The overall control and power management strategy for the proposed hybrid energy system is also developed. The simulation results, given for two scenarios, show the effectiveness of the overall power management strategy and the feasibility of the proposed hybrid system.

ENHANCING WIND/FUEL CELL HYBRID ENERGY SYSTEM

This paper describe of a renewable energy based hybrid energy system with MATLAB implementation results. In order to meet sustained load demand during varying natural conditions, different renewable energy sources need to be integrated with each other. This paper focuses on the combination of wind/fuel cell hybrid energy system. As wind turbine output power varies with wind speed & FC systems can be integrated to ensure that the system performs under all conditions. The result show that the proposed hybrid energy system can be tolerate the rapid change in natural condition and suppress the effect of the fluctuation on the voltage wind turbine the acceptable range.

Dynamic Behavior and Management Strategy of Hybrid Wind/Fuel Cell System

hybrid generation system is considered as a solution for the uncontrolled energy production from such dispersed sources as wind generation. In this paper, modeling and control of wind/FC system is proposed. Dynamics models for the main system components, namely, wind energy conversion system (WECS), fuel cell, electrolyses, power electronic interfacing circuits, hydrogen storage tank and ultra-capacitor are developed. Also, a variable speed wind generation maximum power point tracking (MPPT) based on Adaptative Neuro-Fuzzy Inference system (ANFIS) is presented. Based on the dynamic component model, a simulation model for the proposed hybrid energy system has been developed using Matlab/Simulink and the power flows management strategy are proposed. The result shows that this system can tolerate the rapid changes in wind speed and/or power demand. This results shows also that, the overall power management strategy is effective and the power flows among the different energy sources and the load demand is balanced successfully.