Hybrid Energy System Research Articles

Studi Keselamatan PLTN dalam Sistem Hibrida Tenaga Nuklir dan Energi Terbarukan

Electricity demand in Indonesia is steadily increasing, and it is predicted to reach 390 TWh with 103.06 million customers by 2030. However, Indonesia is also committed to addressing climate change through Act Number 16 of 2016, which ratifies the Paris Agreement to the United Nations Framework Convention On Climate Change. Therefore, it is essential to ensure stable and environmentally friendly energy availability to meet people's needs. One proposed solution is the Nuclear-Renewable Energy Hybrid System (NREHS), which combines Nuclear Power Plants to meet the base load of electricity and other renewable energy sources for energy storage that will be used for the peak electricity load. This system has numerous benefits, particularly regarding environmental friendliness and economic value. However, due to the use of nuclear power in the system, specific attention needs to be paid to nuclear safety issues. This paper describes various safety issues that must be considered when implementing this system. The study analyzed the relationships and influences of nuclear power plants (NPPs) and other power generators concerning safety. This analysis was conducted by referencing international documents and standards regarding external hazards and relevant safety literature in different power generation facilities such as solar and wind power plants. From the studies conducted, it was found that several aspects of nuclear safety must be considered in this system, including external events, Optimization of Specifications for Other Power Plants for Nuclear Reactors, Handling Non-Nuclear Consequences in Nuclear Accidents, and Nuclear Emergency Preparedness and Response. Keywords: NPP, Renewable Energy, Nuclear Safety, Renewable Energy Hybrid System

Family of boost and buck-boost converters with continuous input current and reduced semiconductor count for hybrid energy systems

Family of boost and buck-boost converters with continuous input current and reduced semiconductor count for hybrid energy systems

Optimization of an off-grid PV/biogas/battery hybrid energy system for electrification: A case study in a commercial platform in Morocco

The use of hybrid renewable energy systems is growing as a viable option for clean power generation, fueled by the increasing demand for sustainable energy sources and the need to reduce carbon emissions. In this context, this paper evaluates the optimal configuration, as well as the economic and environmental performances of a hybrid solar PV/biogas/battery energy system designed to provide electricity to a commercial platform in Berkane- Morocco. The optimization model aims to determine the optimal capacity of renewable energy systems achieving the most cost-effective levelized cost of electricity, reducing greenhouse gas emissions, and utilizing locally available renewable energy resources. The model was developed using HOMER software incorporating real-measured data for electricity demand, solar irradiance, and biogas availability. It was found that the PV/biogas/battery combination is very optimal in terms of cost and emissions savings in comparison with the use of only one source of power generation. The optimal design of the energy system results in 231 kW of PV modules, 170 kW biogas generator, a 140-kW converter, and a 201 kWh Li-Ion battery park. The optimization results in an LCOE of 0.280 $/kWh; Moreover, the proposed system would save almost 40 % of carbon dioxide (CO2) emissions in comparison with only biogas system. A sensitivity test has been performed, showing that the proposed hybrid system is sensitive to capital subsidies and discount rates. This study demonstrates the economic viability and environmental benefits driven by the integration of the hybrid of PV/Biogas/Battery system in Morocco, making it an attractive alternative for future sustainable development.

Multi-criteria decision-making for techno-economic and environmentally sustainable decentralized hybrid power and green hydrogen cogeneration system

For global sustainable development, supplying reliable, clean and affordable energy to all is critical. Also to achieve the stringent carbon emission reduction target, the global energy transition is towards increasing the renewable share of total power generation. As renewable resources are intermittent, widely variable and nature dependent, a decentralized hybrid energy system may be the potential solution to address these issues. However, mismatch between energy demand and generation of such systems is a critical problem that needs to be addressed. Excess power generated than local instantaneous demand must be utilized in a sustainable way. Production of hydrogen can address the above issues as it has large capacity and long term power absorption capability. Currently it is considered as a valuable energy carrier. This work proposes to convert the excess electricity of a distributed system to a value added by-product, i.e., ‘green’ hydrogen. This study presented an integrated methodology to evaluate the overall sustainability, i.e., techno-economic and environmental performances of this combined electricity and hydrogen production system. These sustainability assessments do not converge to a single optimal solution. Therefore, a multi-criteria decision making approach is adopted to decide the acceptable sustainable solution. This integrated methodology concludes that the solar-wind-diesel-battery-electrolyser combination is the acceptable optimal solution. It meets the required load and produces hydrogen as a by-product at least cost with optimal environmental impact (cost of electricity-$ 0.252/kWh, cost of hydrogen-$ 2.59/kg, renewable share- 98.4%, payback period- 6.1 yrs, human health- 76476.7 DALY, ecosystem 54.17 species.yr and resource-61521013 USD 2013).

Energy Management Strategies of Solar Rooftop Campus with Battery Energy Storage System (BESS) And EV Supply Equipment (EVSE) using HOMER

Commercial sector has been among the largest source of electrical load demand in Malaysia including educational buildings. Nowadays, distributed energy resources, such as solar photovoltaics (PV) and battery energy storage systems (BESS), are being implemented in educational campus to save and manage its energy consumption. Additionally, electric vehicles (EV) are becoming more popular as they are more environmentally friendly than the traditional gasoline-powered cars. This research aims to examine the cost-effectiveness, environmental and technical aspects of a microgrid system that includes grid-connected solar panels, BESS and EV supply equipment (EVSE). The study was conducted for Universiti Teknologi MARA campus Pulau Pinang. The campus microgrid models are simulated using HOMER software to explore four different of microgrid configurations. The load profiles of the buildings in the campus were gathered and used in the model to identify the optimum microgrid model. The findings show Grid-PV-BESS has the best hybrid energy system based on the weightage sum decision making approach considering multiple criteria assessments. Through this study, a sustainable hybrid energy system in the educational campus can be proposed integrating solar PV, BESS and EVs.

Optimal planning and configuration of adiabatic-compressed air energy storage for urban buildings application: Techno-economic and environmental assessment

As urbanization and demand for energy increase, the importance of localized renewable energy resources and energy storage system solutions becomes more prominent. Adiabatic-compressed air energy storage (A-CAES) has been identified as a promising option, but its effectiveness in decentralized applications is not widely concerned. This study aims to plan and design a decentralized A-CAES system to enhance its significance within urban building infrastructure. The focus is on the optimal design of a decentralized A-CAES system for urban building utilization through a comprehensive analysis of its thermodynamic, techno-economic, and environmental aspects. A sizing-designing approach inducing simulation and optimization is proposed to customize the A-CAES system according to the specific application requirement. To do so, this study investigates several energy management operation strategies (EMOS) toward different potential applications of decentralized A-CAES to maximize the system's value and adaptability during the project's lifetime. Multiple scenarios concerning managing solar PV-surplus power are proposed to investigate the overall performance of the proposed model. Additionally, a sensitivity analysis (post-optimization) is conducted to ensure the model's applicability across different case studies. The results demonstrate that an energy cost saving in the range of 0.015–0.021 $/kWh is achieved for the optimal hybrid system in which the A-CAES system is planned for solar photovoltaic (PV) integration and seasonal load shifting, leading to shaving the grid peak demand. Adopting such an A-CAES-PV hybrid system allows for achieving a 52 % electrical load management ratio and 65 % carbon emission reduction compared to the primary power system (grid). Furthermore, under the worst-case scenario (zero selling back), such an optimal hybrid energy system (HES) achieves a PV self-consumption rate of around 92 % and a payback time of 15.5 years. This analysis provides useful insights for policymakers, building owners, and energy planners interested in implementing sustainable and energy-efficient solutions, especially in the feasibility study phase.

Power Control Energy of a Pumping System (Photovoltaic- Diesel)

Abstract Future Algerian agricultural projects are oriented to the Sahara. Knowing that generally electrical energy is supplied largely by Generator Diesel (DGs). Due to the difficulty and lack of land roads for these desert areas, which creates fluctuations in the fuel supply process for farmers. In order to find a solution to mitigate this fluctuation requires the use of modern technology such as the hybridization of local renewable energy such as solar energy. Our system consists of the integration of a photogenerator (PVG) with a DG to feed a synchronous motor coupled to a central water pump controlled by means of transformers. This work presents an intelligent approach for improving and optimizing the control performance of a system using the Fuzzy Logic Control (FLC) based maximum power point tracking (MPPT) method. In this article, we will analyze a contribution to the use of a hybrid energy system (PVG-DG) according to a management strategy whose purpose is to reduce energy costs and reduce the emission of greenhouse gases (CO2). Our simulation results presented at the end of the article have demonstrated the efficiency and flexibility of the Matlab simulated techniques system based on the actual geographic information of the study area to validate the performance of the proposed system. Which can be used in other practical studies in the future.

Hibrit Güneş-Hidroelektrik (GHE) Sistemine Rezervuar Etkisi

The solar-hydroelectric (SHE) energy system is a renewable hybrid energy system consisting of solar and hydroelectric energy. An optimization algorithm has been designed to work out the installed power size of the SHE hybrid system, which is planned to be integrated into the existing hydroelectric power systems. This designed algorithm provides the optimum installed power with the benefit/cost approach. The value of the hydro cost and also the energy generation is taken from the actual values since it's an existing facility, and also the electricity production and price of the solar power are obtained from the algorithm that works iteratively. This study aims to indicate that more electricity will be produced by regulating water flows due to the reservoir of hydroelectric power plants. Hydro energy enables energy management to be administrated more effectively with the reservoir, which could be a natural enclosure, without using the other energy storage equipment/method. As a result of the study, it's been shown that with the regulation of the hydro facility flows with a reservoir, 180% more solar power capacity installation with 20.9 MW installed power and 12% more electricity production with 75.3 GWh electricity production is provided compared to the unregulated situation.

Modeling and simulation of nuclear hybrid energy systems architectures

Modeling and simulation of nuclear hybrid energy systems architectures

Techno-economic-environmental analysis of off-grid hybrid energy systems using honey badger optimizer

Techno-economic-environmental analysis of off-grid hybrid energy systems using honey badger optimizer

Techno-economic optimization of hydrogen generation through hybrid energy system: A step towards sustainable development

The present study aims to design and optimize a Hybrid Renewable Energy System (HRES) to facilitate a remote community's electricity and hydrogen load demand at Dungri, Uttarakhand, India. The methodology includes an assessment of energy demand, local resource availability, and the nature of the inhabitant. The findings shows techno-economically an optimal HRES, consisting of 90 kW PV, 25 kW Bio-generator, 30 kW electrolyser, 15 kW hydrogen tank, 10 kWh storage and a 30 kW converter with Net present value (NPV) of Rs. 78.4 lakhs, cost of energy (COE) as Rs. 7.61/kWh and cost of hydrogen (COH) Rs. 330/kg. Annual electricity generation is of 250641 kWh/year and yearly average hydrogen generation of 1838 kg through electricity consumption of 80462 kWh/year and can be utilized for 26280 km/year of operation of hydrogen fuelled buses. Furthermore, sensitivity analysis reveals that, rise in the hydrogen load, boost up the system's NPV and COE, whereas,the COH reduces. Amount of annual CO2 emission and avoided are 53.9 kg, 209.12 t, respectively. Moreover, it infers that the proposed system serves isolated rural communities with high-quality energy and satisfies local hydrogen fuel demand in the transportation sector in economically viable manner and achieves the SDG 7 & 8.

Long-term operation rules of a hydro–wind–photovoltaic hybrid system considering forecast information

The large-scale integration of wind and solar energy into cascade hydropower stations increases the complexity of hydraulic/electrical relationships and requires a modification of conventional scheduling mode for better energy system performance. This study focuses on the long-term operation rules for hydro–wind–photovoltaics (PV) hybrid energy systems (HESs). Based on the conventional operation chart, a cascade energy operation chart that couples wind, PV output, and runoff forecasts is proposed to obtain the total output of HES, which can promote the utilization of the joint regulation of cascade hydropower stations. A total output allocation method based on the cascade energy operation chart is established to coordinate the operation of each power station. Then an operation chart optimization model with objectives of maximizing power generation and output reliability is proposed to improve HES performance. The case study reveals that compared with the conventional reservoir operation chart, 1) the optimized cascade energy operation chart increased power generation of HES by 9.2 %; 2) the reservoir impounding timing was delayed, the drawdown timing was brought forward, and the drawdown depth was increased; 3) the reliability of HES power output was improved, and the output corresponding to the 95 % guaranteed rate requirement was increased by 18 %.

A novel day-ahead scheduling model to unlock hydropower flexibility limited by vibration zones in hydropower-variable renewable energy hybrid system

Giving full play to the flexibility of hydropower and integrating more variable renewable energy (VRE) is of great significance for accelerating the transformation of China's power energy system. For middle- to large-sized hydropower units, its irregular vibration zone (VZ) is a major factor affecting its flexibility, because VZs limits the power output and adjustment range. In the existing studies on hydropower unit commitment and flexibility scheduling, VZs only limits the output of hydropower units, while the impact on the flexibility adjustment ability of units is ignored. The hydropower flexibility in day-ahead scheme is overestimated, which increases the risk of system flexibility shortage causing power curtailment and load loss. In this study, a novel day-ahead scheduling model considering the flexibility limited by the VZs and the probability of flexibility shortage is constructed for the day-ahead generation scheme of hydropower-VRE hybrid generation system (HVHGS) to optimize the target load, VRE output and hydropower unit commitments. The impaction of the VZs on hydropower flexibility is firstly modeled by chance constraints and stochastic programming method. Moreover, a data-driven model based on machine learning and an efficient solving approach based on successive linear programming is carry out to describe the uncertainty of VRE output more realistically and ensure the timeliness of optimization scheme, respectively. The proposed model is applied to a real hydropower station in the Hongshui River Basin in China. In 16 representative scenarios, the proposed model can complete the optimization in an acceptable time, with a maximum of 444.57 s. Compared with the traditional interval optimization model, the proposed model effectively improves the flexibility supply capacity of hydropower in the day-ahead scheme. The maximum reduction value of flexibility shortage probability and expectation reach 98.77% and 442.66 MW, respectively. In particular, the flexibility of the model is most obvious under heavy load demand in flood season, and it is almost not at the cost of daily target load adjustment, which provides practical reference for decision makers.

Optimal sizing and techno-economic analysis of the hybrid PV-battery-cooling storage system for commercial buildings in China

Energy systems for flexibility in buildings are hybrid, primarily including rooftop photovoltaics (PV), cooling storage, and battery. Considering their techno-economic patterns, this research establishes an optimization model to determine the optimal technology portfolio and financial advantages of PV-battery-cooling storage systems for commercial buildings in China. The analysis of all cases indicates that cooling storage outperforms batteries in economic benefits, suggesting the prioritization of cooling storage installation. Once the optimal cooling storage rate is exceeded, it is advisable to proceed with batteries. Meanwhile, PV integration significantly enhances the system efficiency and promotes battery utilization. For example, a 40% PV penetration combined with a 0.006 $/(a·kWhe) energy storage investment results in an impressive 27.3% cost reduction in a Beijing mall, while the optimal cooling storage rate decreases from 55% to 40%. Furthermore, the study emphasizes the impact of tariff patterns and electricity demand on the economic feasibility of hybrid energy systems. The museum's substantial annual cooling requirements and nighttime loads make cooling storage favorable, with PV less suitable than the mall and office. Notably, cities like Beijing, Shanghai, Chongqing, and Guangzhou exhibit considerable peak-to-valley tariff differences, yielding higher economic benefits ranging from 23% to 27%. Finally, as battery costs decline and electricity price becomes more volatile, the battery would gradually replace cooling storage, especially when battery cost drops from 150 $/kWh to 70 $/kWh.

Optimization of the power output scheduling of a renewables-based hybrid power station using MILP approach: The case of Tilos island

Hybrid energy systems comprising renewables (mainly wind and solar) and storage systems are increasingly welcome to serve small communities or areas, such as small islands. In particular, the present study deals with the hybrid power station of Tilos, a little island located in the Greek Dodecanese, which includes a 800 kW wind turbine, a 160kWp PV field, and a 2.88 MWh NaNiCl2 battery; the system is also connected to the Kos-Kalymnos electrical network via a submarine cable. Currently, it is used to export its whole energy production under the management of the Greek company Eunice Energy Group. The agreement with the grid regulator is conceived to involve a remuneration for the energy output in three power levels (0 kW, 200 kW, 400 kW), with hourly dispatch provided the day before. Economic penalties will be applied in the near future for failure to respect power levels, whether in the form of excess or deficiency. This must be done in accordance with the available power to avoid surpluses or deficits, as well as excessive curtailment of renewable energy. In this work, a way to optimize energy fluxes of the island is proposed to better exploit the potential revenue, without excessively resorting to curtailments. The optimizations are performed in a Python environment through the “Gurobi” optimization solver, which is based on Mixed Integer Linear Programming (MILP). Scheduling emerges as a result of a rolling horizon approach. The new scheduling method reveals that there is potential for an increase in exported energy by 87.1% and potentially doubles the earnings over the current operation. Furthermore, novel scenarios are proposed to explore how different agreements with the grid operator would shift the optimal solution. Compared to an ideal optimized control under the current restrictions, a scenario that introduces the possibility of shutting down the wind turbine may increase the annual earnings by 10%, while a scenario that introduces a higher power band has the potential to increase annual earnings by 29.1%.

Hybrid energy storage system and management strategy for motor drive with high torque overload

The demand for small-size motors with large output torque in fields such as mobile robotics is increasing, necessitating mobile power systems with greater output power and current within a specific volume and weight. However, conventional mobile power sources like lithium batteries face challenges in surpassing the dual limitations of weight and output power due to constraints imposed by materials and other factors. Therefore, this paper references the approach of high-power hybrid energy systems in automobiles and proposes a battery–supercapacitor hybrid energy storage system (BSHESS) and energy management strategy. The motor is powered by the battery during low torque operating conditions, while the additional output power of the battery is used to charge the supercapacitor. In cases of torque overload, the rapid discharge of the supercapacitor provides the motor with a high current, ensuring instantaneous high output power. Furthermore, the proposed energy management strategy is used to control the charging and discharging processes of the supercapacitor, guaranteeing that the charging process of the supercapacitor does not interfere with the battery’s power supply to the motor, as well as maintaining controllability and stability of the current in the discharge process. The feasibility of the principle is verified through simulations, and we also design a complete prototype of the proposed BSHESS and conduct experiments on the motor. The results demonstrate that the maximum output current to the motor is increased by 150% compared to the original level, and the weight is reduced by 64.7% compared to a pure battery-powered system with same maximum current output. Additionally, the energy management strategy enables a more stable charging and discharging process compared to the unmanaged state.

Techno-economic analysis of a standalone hybrid energy system in Cambodia

This study aims to present an economically feasible and environmental-friendly hybrid energy system that does not connect to the grid. In Cambodia, many rural areas are facing insufficient power supply problems and need more electricity supply. So, the designed system in this research can supply electric power to a community with 30 households in Krong Kracheh, Kratie Province, Cambodia. Three different designs of hybrid systems are considered. The first design is a hybrid system with PV modules, a diesel generator, and a battery. The second design is a hybrid system including a wind turbine, PV modules, diesel generator, and battery, and finally, a hybrid system that contains a wind turbine, diesel generator, and battery as the third design. According to the simulation results, the first configuration is the best design compared to the other two scenarios as it is the most cost-effective. The Present Net Cost, Cost of Energy, and system operating cost is 46,866 $, 0.268 $/kWh, and 2,327 $/yr, respectively. Besides, it has a total of 4,496.29 kg/yr pollutants emitted, which is less than the third configuration but more than the second configuration. The production of electricity for the first configuration is 23,820 kWh/yr, with a renewable fraction of 65.2%.

Multi-objective optimization, comparison of using different biomass fuels in hybrid energy system for electricity-distilled water production based on supercritical CO2 and humidification and dehumidfication cycles

Biomass-derived power generation presents various potential benefits compared to conventional fossil fuel-based power generation. Also, efficient integration of energy systems leads to higher sustainability and effectiveness. This paper presents a biomass-fueled energy system with two open and closed Brayton cycles in the waste heat, of which a humidification and dehumidification system is implemented. The usage of four different biomasses as the fuel of the gasifier is tested and put to comparison from the aspects of thermodynamics, economics, and environment. The Grassman diagram for each layout is presented to signpost the exact point of highest exergy destruction and irreversibility. The optimization based on machine learning techniques is conducted to pinpoint the exact optimum operational conditions. The results indicate that wood offers more sustainability compared to other biomasses, and the amount of energy efficiency, exergy efficiency, and freshwater flow rate produced for Wood biomass in the proposed system are 75.81 %, 36.98 %, and 0.4091 kg/s, respectively. Also, two optimization scenarios have been done for this study. In the initial optimal solution finding, effectivness, unit product cost, and carbon dioxide emission index are equal to 45.9 %, 12.6 $/GJ, and 0.7161 kg/kWh, correspondingly. In the latter scenario, the effectiveness, net power production, and production unit cost of products are equal to 45.9 %, 6580 kW, and 12.61 $/GJ, respectively.

Energy management and sizing of a stand-alone hybrid renewable energy system for community electricity, fresh water, and cooking gas demands of a remote island

Research into the off-grid hybrid energy system to provide reliable electricity to a remote community has extensively been done. However, simultaneous meeting electric, freshwater, and gas demands from the off-grid hybrid energy sources are very scarce in literature. Power- to-X (PtX) is gaining attention in recent days in the energy transition scenarios to generate green hydrogen, the primary product of the process as an energy carrier, which is deemed to replace conventional fuels to reach absolute carbon neutrality. In this study, renewable–based hybrid energy is developed to simultaneously meet the electricity, freshwater, and gas (cooking gas via methanation process) demands for a remote Island in Bangladesh. In this process, an energy management strategy has been developed to use the excess energy to generate both freshwater and the hydrogen, where hydrogen is then converted to natural gas via methanation process. The PV, wind turbine, diesel generator, battery, and fuel cell have been optimized using non-dominating sorting algorithm-II (NSGA-II) to offer reliable, cost-effective solutions of electricity, freshwater, and cooking gas for the end users. Results reported that the PV/WT/DG/Batt configuration has been found the most economic configuration with the lowest COE (0.1724 $/kWh) which is 9 % lower than PV/WT/Batt configuration which has the second lowest COE. The cost of water (COW) and cost of gas (COG) of the PV/WT/DG/Batt system are also the lowest among all the four configurations and have been found 1.185 $/m3 and 3.978 $/m3, respectively.

Large-scale offshore wind integration by wind-thermal-electrolysis-battery (WTEB) power system: A case study of Yangxi, China

Offshore wind power integration is a grand challenge due to the volatility, randomness and intermittency This work presents a wind-thermal-electrolysis-battery (WTEB) hybrid energy system designed to integrate large-scale offshore wind energy and reduce curtailment. The system composes of offshore wind farms (OWF), thermal power plants (TPP), electrolysis station, battery bank. The Qingzhou (geographic name) I-VII offshore wind farms (5000 MW) and the Yangxi (geographic name) coal-fired power plant units #5, #6 (2 × 1240 MW) are taken as a case study. The OWF is the indispensable generator and the renewable fraction increases with integration level. The TPP adjusts the load ratio to meet the changing net load. The electrolysis station consumes the excess electricity and the battery bank time-shifts the electricity to reduce the electrolyzer downtime. The recommended wind-thermal (W-T) capacity ratio is 1.452:1 in the studied case, namely 3600 MW OWF. The WTEB system breaks the trade-off relationship between renewable fraction (50.11%) and curtailment rate (1.48%) compared to traditional wind-thermal (WT) bundled system. The WPEB system improves the electricity shortage rate (4.74%), transmission line capacity factor (61.79%), load following precision (91.79%). The internal rate of return (IRR), levelized cost of electricity (LCOE), levelized cost of hydrogen (LCOH) of WTEB-W3600 are 34.70%, 0.5172 ¥/kWh, 29.76 ¥/kg. The WTEB hybrid energy system for a large-scale offshore wind power integration is first proposed and the techno-economic feasibility analysis proves the feasibility and forward-looking of the system. Collaborative capacity optimization of OWF, TPP, electrolysis station, battery can improve the system performance and economy. The wind-photovoltaic-thermal-electrolysis-battery (WPTEB) system co-locating the OWF and floating photovoltaic (PV) is an important development direction.