Optimal design of a hybrid photovoltaic–wind power system with the national grid using HOMER: A case study in Kerkennah, Tunisia

Energy efficiency has an important role to play in economic growth. The main energy sources used for generating electricity are fossil fuels (petroleum, natural gas, and coal), but these resources are available in limited supplies and they emit heat-trapping gases. Therefore, renewable energy sources, such as solar, wind, geothermal, biomass, and hydraulics, is considered as an alternative to conventional energy sources since they are sustainable and environmentally friendly. However, renewable energy is an inexhaustible, expensive, and often unpredictable source of energy. An alternative solution is to combine one or several renewable energy sources with other energy sources (fossil fuels, batteries, national grid systems). In recent years, the research interest towards the utilization of hybrid energy systems in desalination plants. This study proposed a new approach, based on simulation and multi-criteria decision making to evaluate the best hybrid energy system in desalination plant in Tunisia. The results of the proposed model have determined that system photovoltaic, wind and the national grid is the best energy system in desalination plant.

Global warming and climate change are becoming a global concern. In this regard, international agreements and initiatives have been launched to accelerate the use of renewable energy and to mitigate greenhouse gas (GHG) emissions. Yemen is one of the countries signed on these agreements. However, Yemen is facing the problem that the structure of the power grid is fragile and the power shortage is serious. Accordingly, this paper aims to study the potential for renewable energy in Yemen and assess the technical and economic feasibility of hybrid energy systems. Firstly, this paper introduces the status and challenges of Yemen’s electricity sector, the status of renewable energy, and the status of GHG emission. Secondly, this study proposes the method of optimizing different configurations of off-grid hybrid (solar/wind/diesel engine) energy systems for electrifying various consumers in Taiz province, Yemen under three scenarios of energy strategies. The objective function is to seek the most optimal hybrid energy system that achieves the least cost and most advantageous technical performance, while instigating the best economic scenario of energy strategies. Finally, Homer pro software is used for simulation, optimization, and sensitivity analysis of the designed energy systems. The results found the best economically feasible scenario, the hybrid PV/wind/diesel energy system, among the other scenarios. A photovoltaic (PV)/wind energy system achieved the best technical performances of 100% CO2 reduction, with a 54.82% reduction in the net present cost (NPC) and cost of energy (COE); while the hybrid energy system (PV/wind/diesel engine) achieved the best economic cost of 61.95% reduction in NPC and COE, with a 97.44% reduction of CO2 emission.

Regional integration of renewable energy systems in Ireland – The role of hybrid energy systems for small communities

By creating hybrid energy systems and obtaining a framework that equally satisfies a continuous operation for renewable energy technology, this study presents renewable and sustainable energy options as an integral method to energy transitioning from non-renewable to renewable energy utilization in Cross River State, Nigeria. For a needed load of 2424.25 kWh/day in Cross River State, this study focused on proposing a designed hybrid energy system (HES) nexus, mitigating CO2, and appraisal of the technical and economic viability. To accomplish this, HOMER software was utilized in simulating the ideal components that suggested a HES nexus. The software enabled the selection of the optimal HES using various renewable energy sources since it predicts future electrical demand, wind speed, solar irradiation, and temperature. Economic results obtained showed that the proposed HES's Levelized cost of energy (LCOE), net present cost (NPC), and operating cost (OC) were $0.89/kWh, $10,138,702 and $134,084.37 respectively. Further technical appraisal showed that the renewable energy conversion systems (RECs) make up 78.74% of the proposed HES. The photovoltaic (PV) arrays were primarily responsible for the hybrid energy system's electricity output. The annual electrical energy output was 1,984,111kWh (89.4%), produced by the PV arrays. The generic fuel cell produced the least, at 29,957kWh/year, accounting for just 1.35% of the total electricity produced. However, the wind power plant produced 205,365kWh/year annually. Furthermore, comparing the HES with diesel-powered generators, the system achieves a net-zero carbon emission status. Therefore, it has proven to be the most reliable energy as it will solve the problem of energy demand and reduces carbon emissions in Cross River State, Nigeria

Hybrid renewable energy systems shows a great potential for electricity generation in Bangladesh. Hybrid renewable energy system can be set up such a way that the electricity will add to national grid connection and it will eventually reduce the pressure of electricity demand from national grid. Abundance of renewable energy sources in the form of solar energy provides opportunities of renewable energy based hybrid energy system in the industrial areas of Bangladesh. This work is an in-depth scenario and analysis of the renewable hybrid energy system in Tongi industrial areas of Bangladesh. This study is also includes co-production of diesel generator, solar PV and grid system. Optimization of hybrid renewable energy systems looks into the process of selecting the best components and its sizing with appropriate operation strategy to provide cheap, efficient, reliable and cost effective alternative energy. This paper analyzes all the conditions and constraints of the renewable energy integrated grid connection system with compensation and proposes an optimal combination of energy components for compensating regular grid failure in industrial area with minimizing the pressure of electricity demand from national grid and minimizing the life cycle cost. The final optimization result from HOMER shows that the cost of energy (COE) for 0 hour, 1 hour, 2 hour, 3 hour, 4 hour, 5 hour, 6 hour, 7 hour, 8 hour and 9 hour compensation is respectively $0.092, $0.098, $0.106, $0.113, $0.123, $0.133, $0.144, $0.152, $0.159 and $0.163.

The development of a country depends upon the availability of energy sources for power generation and utilization in end-use sectors. Use of renewable energy sources are gaining more attention for sustainable future of energy future. At present solar, wind, and biomass are the main renewable energy sources that are using for power generation. However, renewable energy sources are intermittent and dependent on the availability. In view of the continuous power requirement for buildings in educational institutes, current work is concentrated on design of optimal Hybrid Renewable Energy System (HRES). Two different hybrid renewable energy systems such as solar-wind and solar-biomass are considered for meeting the building energy demand of an educational institute in Vizianagaram, India. The building hourly, daily, monthly, and yearly energy demand is estimated. Solar energy is assessed using NASA (National Aeronautics and Space Administration). The Vizianagaram biomass web portal is used to assess the availability of biomass. A thorough survey is done for selecting different components such as PV panel, wind turbine, biomass generator, battery, and converter based on the economic and technical aspects. Optimization and sensitivity analysis of the hybrid renewable energy system is done using HOMER software. The results are analyzed with the help of life cycle cost, capital cost, cost of energy (COE), total annual power generation, and monthly average power production. Optimization of hybrid energy system is done using the net present cost (NPC). Further, the sensitivity analysis is implemented for understanding the effect of various parameters on the feasibility of hybrid energy system to provide the energy requirement of the building. It is seen that the solar–biomass hybrid energy system is providing the economic feasible solution for the meeting the electrical energy requirement of the building. The suggested hybrid energy system outcomes could be useful for implementing the hybrid energy system in similar buildings and availability of energy resources in the world for meeting the energy demand.KeywordsHybrid energyWindBiomassOptimization

This paper investigates the exergy and energy rationality of a near-future, two-step hydrogen production system in the Black Sea on a custom-built hydrogen ship with 100% onboard wind, wave, and solar energy system. In the first step of this concept, hydrogen will be produced from the low-salinity seawater by electrolysis utilizing the onboard renewable energy. Part of the hydrogen produced will be used in the second step, which is the major production step, claiming the H2S gas, which is exceptionally rich in the seawater. The hydrogen and sulfur products will be shipped by hydrogen-powered shuttle ships to the nearby city of Sinop to blend hydrogen with the natural gas (NG) to form a hydrogen city. Thus this project presents a novel coupling of the land-side and the sea-side operations with renewable energy and hydrogen in an exergy-based minimum CO2 emissions responsibilities. This on-board H2S exploration concept for hydrogen and sulfur production is compared with the current NG explorations in the Black Sea and the use of NG on the landside. A detailed comparison of the total carbon footprint shows that NG explorations in the Black Sea will be responsible for direct and indirect-nearly avoidable (due to exergy destructions) CO2 emissions, while the ever-increasing H2S threat faced by all Black Sea countries will remain at an increasing rate. A new exergy-based optimum H2S claim depth calculation and control algorithm for onboard operations have also been developed and designed, which shows that economy-based optimization—if ever exists—will be responsible for nearly avoidable CO2 emissions, while the on-board hydrogen production and utilization on the land side have a minimal environmental footprint. None of the earlier studies available in the literature concerning the exact harmful effects of hydrocarbons address exergy rationality. Renewable energy systems like wind turbines and solar energy systems, along with other renewable and waste energy systems like geothermal and wave energy are mostly treated individually, which are not free from large exergy destructions. Therefore, future energy plans with environmental concerns must be carried out from the source to the very last point of demand sectors. This is the specific attribute of this research. Novelty Statement None of the studies about the exact harmful effects of hydrocarbons involve exergy rationality and the consequences of this ignorance on the environment and overall energy budget and economy. Renewable energy systems like wind turbines and solar energy systems, along with other renewable and waste energy systems like geothermal and wave energy are mostly treated individually, which are not free from exergy destructions. For example, a solar photovoltaic (PV) plant generates power but releases heat back without claiming it. This unclaimed heat represents about 50% of the unit exergy of the available solar energy and leads to exergy destruction that is responsible for nearly avoidable CO2 emissions because destroyed thermal exergy has to be offset by spending additional fuel in another system, which most likely is using fossil fuels in a boiler. The term nearly precedes the word avoidable, because exergy destructions may not be completely avoided. Even solar and wind energy systems have exergy destruction components during their operation. Yet, a solar PV and heat system would be a much better choice from the exergy rationality point of view. Although the ongoing increase in the renewable shares in the energy stock, it is essential to follow where the power is used in the built environment. For example, according to Global Wind Energy Council, within the next 10 years 234 GW, within the next 30 years 1400 GW offshore wind power capacity is expected to be installed. However, these installations will never know where this electricity and how this electricity is used in an energy/exergy balance and rationality when coupled to the landside through national and international grids. Therefore, future energy plans with environmental concerns must be carried out from the source to the very last point of demand sectors. Whether off-shore or land-based, wind turbines just generate electric power without asking where the electricity goes and how rational it is used in the built environment. There is no control over the best way of utilizing this wind energy. Instead, hydrogen production with renewables and utilization in next-generation fuel cells produces power and heat (pending on heat distribution tariffs for the fifth-generation district energy systems and LowEx applications, the temperature is the best fit for LowEx applications). The interrupted and unpredictable characteristics of renewables are offset by hydrogen storage.

Solar and wind resources are the two renewable energy sources that are generating the major portion of the renewable energy-based electricity. Both these sources are intermittent in nature when considered separately. But when solar and wind system are combined and operated in hybrid mode, the reliability of electrical system is much better in comparison with the system based on single source of renewable energy. In this paper, a grid-connected hybrid energy system (HES) consisting of solar photovoltaic (SPV) and wind energy (WE) system which is modelled to supply power to 50 MW constant load. HOMER software is used for solar–wind hybrid system modelling by considering five cases in which the load share of SPV are 0, 30, 50, 70 and 100%, while remaining percentage of load is supplied through wind energy system. Soda site at Jaisalmer, Rajasthan (India), is considered for installing the Solar PV–Wind hybrid system. The variations in net present cost and levelized cost of electricity are analyzed by varying turbine loss factor and grid power purchase price. It was estimated that the renewable fraction is maximum for the hybrid system in which share of each of solar and wind energy is 50% of the load, if turbine losses are taken into consideration. Assuming the power purchase price of Rs. 6/kWh from the grid and supply price of Rs. 5/kWh to the grid, levelized cost of electricity for the system is Rs. 2.92/kWh, Rs. 3.37/kWh and Rs. 3.24/kWh when the wind turbine overall loss factor is assumed as 0, 11.55 and 16.20%, respectively.

Renewable energy sources (RES) have already become important alternative electric power generation technologies, due to the adverse impacts of global warming brought about by the use of fossil-fuelled generation. To combat such impacts, a hybrid energy system which consists of more than one source of renewable energy would replace conventional electricity generation for Malaysia’s longhouses existing in rural areas. Due to the limitation of electricity access in such areas, a hybrid system that consists of solar PV and wind energy as well as energy storage is proposed in this paper as a standalone RE system for electricity supply. Modelling of the hybrid system is then carried out based on selecting the most suitable system components, such as PV arrays, wind turbines, batteries and the inverter that satisfy both the technical and financial feasibility criteria. The model is then simulated using HOMER software to calculate the net present cost and the levelised cost of energy (LCOE). Results of the hybrid system simulation are compared with a diesel power generation, representing conventional energy supply, as the existing energy source. The comparison highlights the economic viability of the proposed hybrid system as a sustainable energy alternative to supply electricity to the longhouse.

Hybrid energy systems are renewable energy system combined in a complementary fashion to ensure dependable power supply at competitive cost. Diesel generators (DGs) are also added here as a back-up source of supply. For remote areas far from a transmission grid, these systems can provide a reliable and cost-effective supply. Addition of DG could instigate environmental pollution in such remote unpolluted areas. In the present work, optimal sizing of hybrid energy system has been attempted for a remote village cluster of Uttarakhand (India) to make available desired power supply at minimum environmental effluence. Hybrid Optimization Model for Electrical Renewable (HOMER) software from National Renewable Energy Laboratory, USA has been employed to attain the objective. The software offered several feasible systems, ranked on the basis of net present cost (NPC). All such systems are further analysed for emissions they have made in the environment. Hence, the optimal system fulfilling the criteria of minimal environmental degradation with sufficiently minimum NPC has been searched for. In the present work, the most appropriate system offered on the basis of NPC is the one which has five wind turbines (10 kW each), one DG (65 kW) and 25 batteries (6 V, 6.94 kW h each). The NPC of the system is $1,252,018, whereas its initial capital cost and levelised cost of energy (COE) are $94,233 and $0.292/kW h, respectively. After further analysis of all the feasible systems on the basis of environmental effluence, the most feasible system explored is the one which has minimal emissions of various pollutants such as carbon dioxide, carbon monoxide, hydrocarbon, particulate matter, sulphur dioxide and nitrous oxide. The system has been obtained on a compromised NPC of $1,270,921 with a capital cost of $148,133 and COE of $0.296/kW h. Components of the system include five wind turbines (10 kW), a 9 kW PV panel and a 65 kW DG along with 30 batteries (6 V, 6.94 kW h each). The system so obtained would prove to be a feasible, optimally sized and sustainable power supply alternative for remote unelectrified hilly rural area.

This paper presents eight hybrid renewable energy (RE) systems that are derived from solar, wind and biomass, with energy storage, to meet the energy demands of an average household in the six geopolitical zones of Nigeria. The resource assessments show that the solar insolation, wind speed (at 30 m hub height) and biomass in the country range, respectively, from 4.38–6.00 kWh/m2/day, 3.74 to 11.04 m/s and 5.709–15.80 kg/household/day. The HOMER software was used to obtain optimal configurations of the eight hybrid energy systems along the six geopolitical zones’ RE resources. The eight optimal systems were further subjected to a multi-criteria decision making (MCDM) analysis, which considers technical, economic, environmental and socio-cultural criteria. The TOPSIS-AHP composite procedure was adopted for the MCDM analysis in order to have more realistic criteria weighting factors. In all the eight techno-economic optimal system configurations considered, the biomass generator-solar PV-battery energy system (GPBES) was the best system for all the geopolitical zones. The best system has the potential of capturing carbon from the atmosphere, an attribute that is desirous for climate change mitigation. The cost of energy (COE) was seen to be within the range of 0.151–0.156 US$/kWh, which is competitive with the existing electricity cost from the national grid, average 0.131 US$/kWh. It is shown that the Federal Government of Nigeria favorable energy policy towards the adoption of biomass-to-electricity systems would make the proposed system very affordable to the rural households.

The current paper is to investigate the shortage problem of fresh water in Libya and to propose alternative solutions by renewable and sustainable energies. This problem is not only in Libya but it is one of the most serious social and environmental challenges facing many countries in the world, especially those countries which do not have natural resources or any types of energies. Although Libya is located in a dry and semi-arid region of Africa, it is very rich in conventional energy resources, mainly the oil, and renewable energies such as solar and wind energies. In addition to that it has about 1700 km border on sea, which is very helpful to establish many desalination plants either by conventional or renewable energies. Nowadays the shortage problem of water in Libya is solved partly by ground water resources and desalination plants which are not enough. In the other hand the quantity of oil is limited to a certain period of time with other environmental impacts of this resource Here, this paper is to study the water resources as well as conventional and energy situations in Libya and suggest the most appropriate solutions for today and future by combining solar and wind energies with desalination processes. This can be done by encouraging and supporting private and de-central solar desalination technologies and establishing central desalination units for high productivity by using solar thermal or electrical processes.

ABSTRACTResource estimation and load estimation are primary inputs in the designing of Hybrid Renewable Energy System (HRES). Otherwise, HRES system may become oversize or undersize without vigorous load and resource assessment. Oversizing or undersizing may also affect the economic viability of such a system in terms of higher energy generation cost and lower reliability. Proper resource estimation for hybrid energy system not only provides sustainable energy but also improves reliability and stability. In the present study, sizing optimization of a hybrid energy system, consisting of hydro-solar-battery-diesel, has been carried out. To begin with, three villages in the Chanju Panchayat of district Chamba in Western Himalayan Himachal Pradesh (HP) has been considered based on the local resource availability (corresponding to hydro and solar potential). Sizing optimization of the hybrid system (at these villages) is carried out using particle swarm optimization (PSO) method with energy index ration 1. In the designing of HRES, the input parameters such as available solar radiation and hydro discharge has been used. These parameters are estimated by using artificial neural network (ANN) and hydrology estimation techniques. Addition to the renewable energy fraction based on the present energy demand of selected villages, the cost of energy (COE), net present cost, and emissions of carbon dioxide from diesel generator are also estimated. It is worth mentioning that the use of Diesel generator is included to deal with the intermittency of the renewable energy resources. The 18 possible combinations comprising a different component has been investigated. The results present that the 15th combination using PSO algorithm is most cost-effective. The least cost of energy of HRES is estimated at 5.37₹/kWh, and the corresponding net present cost is 26288078₹million. The combination 3rd is most effective if renewable fraction (RF) is considered as the main objective. The total fuel used in this combination is 2218 l and share of renewable is approx. 98%.

In recent years, small-scale nuclear power plants, particularly micro nuclear reactors, have emerged as viable alternatives, gaining importance in the technical and economic operation of electrical distribution systems. As consumer demand for electricity continues to rise, the use of renewable energy sources and nuclear energy has become essential, especially as dependence on conventional energy sources grows increasingly unsustainable from an environmental standpoint. In this study, mathematical models for various Hybrid Energy Systems (HES) are developed using both single and multi-objective functions. Active Power Loss (APL) is selected as the first single-objective fitness function, while the total Net Present Cost (NPC) serves as the second. These two objectives are also considered together in a multi-objective optimization framework. The White Shark Optimizer is employed to determine the optimal configuration that achieves an improved voltage profile, reduces power losses, and minimizes both cost and greenhouse gas (GHG) emissions. The proposed modeling and simulations are conducted using MATLAB software, and the optimization methodology is applied to three types of HES on two standard radial distribution networks; the IEEE 33-bus and IEEE 69-bus systems. The three HES configurations analyzed are; Nuclear-Renewable Hybrid Energy System (N-R HES), Stand-alone Fossil Fuel-based Thermal Generators (FFTGs), and Renewable-Fossil Fuel Hybrid Energy System. Among the three, the N-R HES demonstrates the most favorable between system performance, cost efficiency, and environmental impact. Results and analysis prove that N-R HES is the most effective solution for sustainable energy generation and decarbonization, offering the lowest NPC and APL.

Ocean-going ships are one of the primary sources of Greenhouse Gas (GHG) emissions. Several actions are being taken to reduce the GHG emissions from maritime vessels, and integration of Renewable Energy Sources (RESs) is one of them. Ocean-going marine ships need a large amount of reliable energy to support the propulsive load. Intermittency is one of the drawbacks of RESs, and penetration of RESs in maritime vessels is limited by the cargo carrying capacity and usable area of that ship. Other types of reliable energy sources need to be incorporated in ships to overcome these shortcomings of RESs. Some researchers proposed to integrate fossil fuel-based generators like diesel generators and renewable energy in marine vessels to reduce GHG emissions. As the penetration of RESs in marine ships is limited, fossil fuel-based generators provide most of the energy. Therefore, renewable and fossil fuel-based hybrid energy systems in maritime vessels can not reduce GHG emissions to the desired level. Fossil fuel-based generators need to be replaced by emissions-free energy sources to make marine ships free from emissions. Nuclear energy is emissions-free energy, and small-scale nuclear reactors like Microreactors (MRs) are competent to replace fossil fuel-based generators. In this paper, the technical, environmental, and economic competitiveness of Nuclear-Renewable Hybrid Energy Systems (N-R HES) in marine ships are assessed. The lifecycle cost of MR, reliability of the proposed system, and limitations of integrating renewable energy in maritime vessels are considered in this study. The proposed N-R HES is compared with three different energy systems, namely ‘Standalone Fossil Fuel-based Energy Systems’, ‘Renewable and Fossil Fuel-based Hybrid Energy Systems’, and ‘Standalone Nuclear Energy System’. The cost modeling of each energy system is carried out in MATLAB simulator. Each energy system is optimized by using the Differential Evolution Algorithm (DEA), an artificial intelligence algorithm, to find out the optimal configuration of the system components in terms of Net Present Cost (NPC). The results determine that N-R HES has the lowest NPC compared to the other three energy systems. The performance of the DE algorithm is compared with another widely accepted artificial intelligence optimization technique called ‘Particle Swarm Optimization (PSO)’ to validate the findings of the DE algorithm. The impact of control parameters in the DE algorithm is assessed by employing the Adaptive Differential Evolution (ADE) algorithm. A sensitivity analysis is carried out to assess the impact of different system parameters on this study’s findings.