Hybrid Energy System Research Articles

Techno‐economic optimization of a hybrid system composed of pumped hydro storage, photovoltaic module, and diesel generator in a multi‐objective framework

AbstractHybridization of photovoltaic (PV) module (as a non‐dispatchable resource), diesel generator (as a dispatchable source), and pumped hydro storage (PHS) (as an energy storage) can provide a promising hybrid energy system (HES). The main outlook of the present study is to develop an efficient multi‐objective framework for optimal design of an off‐grid PV/diesel/PHS HES in which a wide range of parameters related to PHS system is optimized. In the optimization framework, nine decision variables (number of PV modules, number of diesel generators, reservoir installation height, reservoir depth, reservoir diameter, pump's rated power, turbine's rated power, charge pipe diameter, and discharge pipe diameter) are optimized with respect to two objective functions: total net present cost (TNPC) and loss of power supply probability (LPSP). To determine how TNPC is affected by the change of the input variables, a sensitivity analysis is conducted by varying capital cost of PV, PHS, and diesel generator. To obtain a well‐distributed and widely spread Pareto front, a multi‐objective chaotic crow search algorithm (MO‐CCSA) is introduced. Simulation results show that at LPSP = 0% and 5%, levelized cost of energy is around 0.59 and 0.55 $/kWh, respectively. Moreover, variation of the PV capital cost has a significant impact on the TNPC value.

A review of advanced cooling methodologies for solar photovoltaic and thermoelectric hybrid energy systems

A review of advanced cooling methodologies for solar photovoltaic and thermoelectric hybrid energy systems

An effective sizing and sensitivity analysis of a hybrid renewable energy system for household, multi-media and rural healthcare centres power supply: A case study of Kaele, Cameroon

The vast majority of rural Africans lack access to clean, reliable, and sustainable electrical energy. This has deprived rural inhabitants of the opportunity to receive advanced healthcare delivery and modern education. In this study, an off-grid hybrid system composed of solar panels, wind turbines, battery banks and diesel-powered generators has been designed to fulfil the electrical loads requirements of a household, a multi-media and healthcare centres situated at Kaele, Cameroon. Initially, the wind and solar potential of Kaele were investigated and four meta-heuristics algorithms, namely, the colliding bodies’ optimization, charged system search, teaching-learning-based optimization (TLBO) and the water evaporation optimization algorithms are applied to the hybrid system and the results are compared with regards to the system net present cost (NPC). Thereafter, three off-grid hybrid systems: PV/Wind/Battery/Diesel, PV/Battery/Diesel, and Wind/Battery/Diesel were compared based on a techno-economic and environmental analysis. The results showed that, the mean yearly wind speed and solar radiation of Kaele are 6.7 m/s and 7.20 kWh/m2/day, respectively. Comparing the search power of the aforementioned algorithms on the sizing problem, it has been found that the TLBO algorithm produces better results than the other algorithms. The results also showed that, the PV/Wind/Battery/Diesel configuration is the cost-effective option for supplying the household, multi-media and healthcare centres. The obtained optimal combination and the NPC of the PV/Wind/Battery/Diesel system are as follows: For household, the most appropriate configuration combines 9 solar panels, 2 wind turbines, 33 battery banks, 1 diesel generator and the obtained NPC corresponds to 26111.2$; for the multi-media centre, 52 solar panels, 2 wind turbines, 96 battery banks and 1 diesel generator which resulted to a NPC of 55511.2$; and for the healthcare centre, the ideal configuration consists of 13 solar panels, 1 wind turbine, 13 battery banks and 1 diesel generator with a NPC of 19008.7$. The cost of energy of the optimal system was found to be 0.2419$/kWh, 0.2195$/kWh and 0.2158$/kWh for household, multi-media and healthcare establishments, respectively. The results also revealed that for household and healthcare centre the obtained break-even grid extension distance was 0.443 km and 1.23 km, respectively for the PV/Wind/Battery/Diesel system. Since this separation is smaller than the nearest grid extension distance of 5 km, it is concluded that the proposed hybrid energy system is suitable for powering the household, multi-media and healthcare centres in Kaele, Cameroon. Finally, a sensitivity analysis of each relevant component cost, resources availability and microeconomic variables of the PV/Wind/Battery/Diesel system is carried out to acquire a more suitable configuration.

Economic Analysis of On-Grid Photovoltaic-Generator Hybrid Energy Systems for Rural Electrification in Indonesia

Economic Analysis of On-Grid Photovoltaic-Generator Hybrid Energy Systems for Rural Electrification in Indonesia

Deriving long-term operating rules of the hydro-wind-PV hybrid energy system considering electricity price

To integrate large-scale variable renewables into the power grid, the complementary operation of multiple energy sources such as hydropower, wind, and solar photovoltaic is favored worldwide. However, it is challenging to derive long-term operating rules of the hydro-wind-PV system (HWPES) in the electricity market because of the difficulty of accurately estimating the benefit and the power curtailment occurs in the short-term. To address this issue, an operating model of the HWPES was established by considering long-term electricity prices simulated with a short-term model. Then operating rules were derived with the benefit objective. Jinping I HWPES in Yalongjiang River of China was selected as a case study. Results indicate that the relationship between available energy and reservoir storage is suitable to form operating rules for both benefit-maximization and generation-maximization schemes. The operating rules from March to June are significantly different influenced by electricity prices. Compared with the conventional scheme, the power generation and benefit were improved by 0.31 billion kWh (1.50%) and CNY 0.098 billion (2.02%) for the benefit-maximization scheme, while improved by 0.44 billion kWh (2.10%) and CNY 0.026 billion (0.53%) for the generation-maximization scheme. Therefore, the proposed method is effective to guide hybrid system operations in the power market.

Exergy, exergoeconomic and exergoenvironmental assessments of experimental hybrid energy systems for hot water production to improve energy sustainability

Hybrid energy systems have proven their efficacy in improving energy sustainability. This paper focuses on the design and evaluation of various hybrid energy systems for hot water production in the experimental plant of the Laboratory for Quality Control in Buildings. The experimental facility was created to test and control various systems for energy supplies in buildings. In this work, three thermal installations were investigated: (1) a combined boiler cogeneration system, (2) a combined boiler solar collector system, and (3) a combined boiler heat pump system. After configuring each system in the laboratory, defining the control, and running the experimental essay, the corresponding data were obtained and treated. The exergy concept matches very well with the goal of promoting new systems that efficiently integrate renewable and nonrenewable energy resources. The exergy analysis and its extended assessments, the exergoeconomic and the exergoenvironmental, were applied to the designed systems. The results show that DHW production by the combined boiler solar thermal collector system is the most expensive in terms of the exergy cost index (about 33.29 kWhex/kWhex). DHW production by the combined boiler cogeneration system offers the lowest exergy unit cost (about 21.15 kWhex/kWhex). Based on economic and environmental indexes, DHW production by the combined boiler solar thermal collector system is the most suitable option. Its unit exergoeconomic cost is around 2.15 €/kWhex, and its exergoenvironmental unit impact is equal to 9.35 kg CO2/kWhex.

4E and Multi-criteria Optimization of a New Alternative Intercooling Method for Modified Brayton Cycle on the Operation of a Hybrid Energy System

4E and Multi-criteria Optimization of a New Alternative Intercooling Method for Modified Brayton Cycle on the Operation of a Hybrid Energy System

Optimal energy optimization of the integrated hybrid energy system considering storage system performance

Optimal energy optimization of the integrated hybrid energy system considering storage system performance

Hybrid renewable energy systems: the value of storage as a function of PV-wind variability

As shares of variable renewable energy (VRE) on the electric grid increase, sources of grid flexibility will become increasingly important for maintaining the reliability and affordability of electricity supply. Lithium-ion battery energy storage has been identified as an important and cost-effective source of flexibility, both by itself and when coupled with VRE technologies like solar photovoltaics (PV) and wind. In this study, we explored the current and future value of utility-scale hybrid energy systems comprising PV, wind, and lithium-ion battery technologies (PV-wind-battery systems). Using a price-taker model with simulated hourly energy and capacity prices, we simulated the revenue-maximizing dispatch of a range of PV-wind-battery configurations across Texas, from the present through 2050. Holding PV capacity and point-of-interconnection capacity constant, we modeled configurations with varying wind-to-PV capacity ratios and battery-to-PV capacity ratios. We found that coupling PV, wind, and battery technologies allows for more effective utilization of interconnection capacity by increasing capacity factors to 60%–80%+ and capacity credits to close to 100%, depending on battery capacity. We also compared the energy and capacity values of PV-wind and PV-wind-battery systems to the corresponding stability coefficient metric, which describes the location-and configuration-specific complementarity of PV and wind resources. Our results show that the stability coefficient effectively predicts the configuration-location combinations in which a smaller battery component can provide comparable economic performance in a PV-wind-battery system (compared to a PV-battery system). These PV-wind-battery hybrids can help integrate more VRE by providing smoother, more predictable generation and greater flexibility.

Optimal capacity configuration of the hydro-wind-photovoltaic complementary system considering cascade reservoir connection

To address the critical issues on environmental pollution and energy consumption, humans began vigorously developing and employing renewable energy sources (RESs). Hydro-wind-photovoltaic(PV) complementary system plays an indispensable part in the sphere of renewable energy research, while the optimal capacity proportion serves as a foundation and premise for building hybrid energy systems. Taking the lower portion of the Jinsha River in Sichuan Province as an example, this research presents a novel capacity configuration model of hydro-wind-PV complementary systems. Based on the consideration of cascade hydropower station connection, the model aims to minimize discarded energy and maximize delivery channel utilization. A new DE based on chaotic local search is then employed to solve the model. The result shows that the optimal proportions for the complementary system with 35 GW, 40 GW and 45 GW of delivery channel capacity are (0.93,0.93), (1.18,1.18) and (1.35,0.35), respectively. Meanwhile, as the affordability of complementary systems increases, the total installed capacity of wind power and photovoltaic power that may be accessible will also rise. Consequently, this paper not only offers a novel strategy for tackling similar issues on optimal capacity configuration, but also makes a contribution to maximizing the accessed installed capacity of RESs.

Techno-economic assessment and optimal design of hybrid power generation-based renewable energy systems

This study presents a techno-economic analysis of five different hybrid energy systems (HES)-based renewable energy sources (RES) in the northern region of Saudi Arabia. It aims to provide valuable insights into the economic feasibility, technical compatibility, and environmental implications of these systems. To carry out this analysis, hybrid optimization of multiple energy resources (HOMER) software is used. Parameters such as total net price cost (TNPC), cost of energy (COE), initial capital cost (ICC), energy generation and consumption, excess and unmet energy, renewable energy (RE) fraction, and emissions were considered to assess the different HES configurations. The findings demonstrate that the grid-connected photovoltaic/wind turbines (PV/WT) system is the best option in terms of economic perspective with TNPC and COE of $213,099 and $0.0480/kWh, respectively followed by grid-connected PV/fuel cell (FC)/WT and stand-alone PV/diesel generator (DG)/WT/battery systems. The PV/battery and PV/FC/WT/battery green hybridization are the highest cost-effective due to their high initial and replacement battery costs. The grid-connected PV/WT and PV/DG/WT/battery systems are the most efficient in meeting load demand, while the PV/battery and PV/FC/WT/battery hybridization have the highest excess and unmet energy. From an environmental perspective, the stand-alone HES consisting solely of RESs, i.e., PV and batteries, has the lowest emissions, making it one of the most environmentally friendly options. Following closely is the PV/FC/WT/battery configuration, which also demonstrates low emissions. On the other hand, the grid-connected PV/WT system exhibits the highest total GHG emissions, rendering it the least environmentally friendly option. This research provides decision-makers, researchers, and stakeholders with valuable information for selecting the optimal hybrid energy systems, taking into account economic, technical, and environmental considerations.

Integrated hydrogen fuel cell power system as an alternative to diesel-electric power system for conventional submarines

A hydrogen fuel cell based hybrid energy system is designed and analyzed to be used in conventional submarines for propulsion and power management. This system is proposed as an alternative to the diesel-electric system. This system eliminates the need for the submarine to surface and hence can continuously operate while submerged underwater. This hybrid system produces electricity, heat, and purified water. Onboard storage carries hydrogen and oxygen that feeds directly to a proton exchange membrane fuel cell (PEMFC). Analyses are performed to determine if the PEMFC based power system can successfully replace the conventional diesel-electric power system for a medium size (displacement of 3000-ton) diesel-electric submarine. The use of PEMFCs onboard the submarine reduces 261,000 kg mass, and frees-up 148 m3 space compared to the diesel-electric system. More importantly, the submarine can operate submerged for the entire duration of its mission with the PEMFC based power system.

Investigating the Effects of Different Types of Battery Impacts in Energy Storage Systems on Standalone Hybrid Renewable Energy Systems

Energy plays an important role in the development of a country. Developing countries tend to lean towards the use of domestic renewable energy sources to reduce their dependency on foreign energy. However, when looking at the world as a whole, the share of fossil fuels in energy production is at high levels. Due to the rapid depletion of fossil fuels and their increasing costs, as well as the environmental damage they cause, electricity generation from cheaper and cleaner renewable energy sources is being targeted in the area where work will be done. Hybrid energy systems are used in conjunction with backup Unitss due to the variable nature of renewable energy sources such as wind and solar. In this study, a hybrid energy system with solar-wind-diesel generator-battery components was designed through HOMERPro software to meet the electricity demand of the closed prison in Burhaniye district of Balikesir. Simulations were carried out by applying 5 different battery scenarios in the hybrid energy system, and the optimum result was obtained. As a result, the effect of the batteries used on the system was examined, and the vanadium redox battery system with a high renewable energy ratio and the lowest Units energy cost was determined to be the most optimum.

An Improved DC-DC Boost Converter for Energy Harvesting

A novel dual-input DC-DC boost converter that can perform the integration of harvested energy from solar and vibrational input energy sources is proposed. Firstly, the background of a hybrid energy system that relates to multi-input DC-DC converters is discussed, and the limitations of the current designs of power converter ICs are highlighted. A detailed design analysis of the proposed converter was done to justify its performance. A current and voltage stress analysis has been performed to ensure suitable switching devices are selected for the converter. Two different power control strategies are proposed for the DIDCB converter to manage output voltage during source and load-side disturbances. Performance analysis of the circuit is carried out using MATLAB Simulink software. Different duty ratios for power switches in the converter were tested to determine the maximum boost ratio and the highest efficiency that can be achieved by the converter. To demonstrate the feasibility of the proposed converter, the performance of the converter is compared with existing converter topologies. The proposed converter achieved a high efficiency of 99.4%, had less fluctuation in the output voltage, and had reduced overshoot. In addition, the proposed converter demonstrated a simpler configuration and required fewer component counts, which helped reduce the cost and size of the system.

Techno-economic feasibility analysis of grid configuration sizing for hybrid renewable energy system in Turkey using different optimization techniques

Today, with a human population of 7.5 billion, increasing power consumption, and widespread use of high-technology equipment, the need for energy in the world is increasing day by day. The damage to nature caused by non-renewable energy resources and the economic and political disadvantages they cause in countries that must import these resources have led the world to search for alternative energy sources. One of the most important benefits of renewable energy sources is that they can create hybrid energy systems with other energy sources. Hybrid energy systems are structures in that more than one energy generation unit works together to feed the electrical load. In this paper, a hybrid system will be designed by using Homer PRO, to supply the energy consumed in the residential areas of Karaburun and Urla districts of Izmir province in Turkey with hybrid renewable energy systems. Systems of different sizes are designed for 50%, 75%, and 100% penetration rates, and sales to the grid are constrained to 0%, 25%, 50%, and no constraint on sales. Sensitivity analyses have been performed for 10% and 20% more power required by the load. Techno-economic analyses were done for the systems and the optimal system has been identified. The power flow of the optimal system is inspected by defining the network in Python and Fire Hawk Optimizer (FHO), Grey Wolf Optimizer (GWO), and Particle Swarm Optimization (PSO) are used for optimal sizing of the system. The optimal system has a Net Present Cost (NPC) of $52.3 M, 34 wind turbines, and 954 kW PV with conditions of 100% penetration and no restrictions on sales to the grid. FHO proposed 26 wind turbines and 780 kW PVs for Urla and 8 wind turbines, and 174 kW PVs for Karaburun. GWO proposed 25 wind turbines and 747 kW PVs for Urla, 9 wind turbines, and 165 PVs for Karaburun. PSO offered 24 wind turbines and 708 kW PVs for Urla, 10 wind turbines, and 246 kW PVs for Karaburun. When there is no sale to and 25% sales to the grid, it is seen that the optimal scenario is the system with a 50% penetration rate. In fully sale-constrained systems, NPCs are higher than the base system and they can never pay for themselves compared to the base system. It is concluded that smaller-sized systems are more suitable for systems with high constraints. The proposed FHO algorithm and GWO algorithm react to increasing penetration ratios by enlarging the system size in the regions with high load demand. PSO sizes the system like predictions by load demand. FHO reacts quicker to increasing penetrations than PSO and GWO. FHO algorithm is found to be usable to solve optimal power flow problems and optimal system sizing.

Optimal sizing and techno-enviro-economic evaluation of a hybrid photovoltaic/wind/diesel system with battery and fuel cell storage devices under different climatic conditions in Cameroon

Due to advancements in renewable energy technology and their ability to mitigate the issue of global warming, solar and wind energy sources are becoming increasingly popular for power generation. However, the intermittent nature of these sources means that their availability does not always correlate with load fluctuations. Hence, to solve the unpredictability concerns associated with solar and wind energy sources, they may be integrated with storage technologies and conventional energy sources (diesel generators) in a hybrid energy system (HES) to continuously supply the load demand. This paper performs a techno-economic and environmental assessment of hybrid systems integrating photovoltaic (PV), wind turbine generator (WT), and diesel generator (DSL), considering fuel cell (FC) and battery (BAT) storage devices, to supply three non-domestic loads at different locations in Cameroon, namely, Fotokol, Idabato, Kousseri, and Figuil. The Cuckoo Search Algorithm (CSA) is introduced to optimally size the various components of the proposed systems in order to fulfill the load demands in the most cost-effective manner with excellent reliability. The results show that in the short term period, hybrid systems incorporating battery storage devices are more cost effective than fuel cell storage systems. Indeed, the most optimal system found was PV/WT/BAT/DSL at the city of Idabato, with a COE of 0.151$/kWh, 0.180$/kWh, and 0.220$/kWh for high, medium, and low consumers, with corresponding break-even distances of 0 km, 0.14 km, and 0.44 km, respectively. Traditionally, using diesel generator systems for power generation costs 0.469$/kWh, 0.618$/kWh, and 0.766$/kWh, with CO2 emissions of 13694.3 kg/year, 10351.4 kg/year, and 8978.1 kg/year for high, medium, and low consumers, respectively. However, using the PV/WT/BAT/DSL configuration at Idabato in comparison to the conventional diesel generator reduces CO2 emissions in this locality by 94.32%, 95.22%, and 93.79% for high, medium, and low consumers, respectively. On the other hand, the PV/WT/FC/DSL hybrid system at Idabato presents COE of 1.018$/kWh, 1.655$/kWh, and 2.289$/kWh, with saving CO2 emissions of 91.27%, 91.76%, and 94.63% for high, medium, and low consumers, respectively.

A simplified control method for a water heating load coupled to a hybrid energy system to improve inverter longevity

In this paper, the temperature characteristics of an inverter is determined through experimental validation. The experiment involves testing under two load scenarios. The first of which considers a low inverter load, which represents a baseload at approximately 18% of the maximum rated power of the inverter. The second includes an energy intensive water heater load, which increases the loading on the inverter to above 85%. The aim of this paper is to ensure that the operating limits with respect to the inverter temperature is maintained to at least 10% below the upper limit of the device. The experimental results indicated that the rate of change of the inverter temperature was 2.988 °C/min when loaded above 85% and −1.277 °C/min after returning to the 18% rated output power level. This indicated that if the inverter is subjected to a high load of above 85% for a certain amount of time and the operating temperature has reached its acceptable maximum limit, roughly twice the amount of time is necessary to cool the components down enough for another high loading event. A basic fuzzy logic control method is proposed to maintain the inverter temperature within acceptable limits to improve overall inverter longevity.

Site Selection for Sustainable Wind-Solar Hybrid Energy Harvesting Plant

The world’s energy landscape is undergoing rapid transformation as societies strive towards renewable and sustainable power sources in response to the need for energy security and climate change. Depletion of fossil fuels and increasing focus on environmental sustainability have been significant drivers in this global shift towards renewables. Among the promising solutions, solar-wind hybrid energy systems have gained attention, capitalizing on the complementary nature of solar and wind resources. However, selecting the optimal site for these hybrid plants is crucial for their successful implementation and efficiency. This research introduces a comprehensive methodology for site selection, seamlessly integrating the Delphi method and Analytic Hierarchy Process (AHP). The Delphi method harnesses expert consensus to distil essential criteria, while AHP offers a structured framework to evaluate and prioritize these criteria. The results showed successful utilization of the AHP and Delphi techniques for evaluating the optimal location selection among different cities for solar-wind hybrid energy harnessing in the northwest region of Pakistan. The key factors for selection of optimal location were identified through expert feedback and analysis. Among the selected key main criteria, resource availability and infrastructure and socio-economic factors emerged as the top-ranked criteria in this study. The results of this study hold significant relevance and should be duly considered for solar-wind power project site selection, while also offering opportunities for further enhancements in the future.

Two-Layered Hierarchical Optimization Strategy With Distributed Potential Game for Interconnected Hybrid Energy Systems.

Due to the existence of different stakeholders, it makes competitive game characteristic in hybrid energy systems (HESs). Combined with the high-dimensional complexity and output uncertainty of distributed energy resources, the optimal operation of HESs can be a more challenging problem. Here, this article proposes a potential game-based two-layered hierarchical optimization strategy to deal with this problem. With consideration of its high-dimensional complexity, a two-layered hierarchical HES model is created, consisting of an upper-level and a lower-level model. For properly solving competitive relationships among different stakeholders in the upper-level model, a multiagent system for stakeholders is created and a potential game is employed with a distributed primal-dual perturbed algorithm, and its convergence and optimality have been both proved. Moreover, an uncertainty and robustness analysis is done with coordination between lower and upper models, which deduces a feasible robust uncertainty interval in the lower-level model. For better dealing with the lower-level model, a gradient descent-based multiobjective differential evolution (GD-MODE) algorithm is utilized to optimize the economic cost and emission issue simultaneously, producing a set of Pareto-optimal schemes. Combined with simulation results, it is proven that the proposed method can reduce computational complexity as well as properly deal with uncertainty problems for the optimal operation of HESs.

Enhancing Climate Adaptation Through Hybrid Energy Systems

This review investigates the potential of hybrid energy systems in bolstering climate adaptation within power generation. By seamlessly integrating renewable energy sources with conventional counterparts, these systems offer heightened resilience against climate extremes. This research analyses the multifaceted benefits, address challenges, and present optimization methodologies, emphasizing the interdisciplinary essence of such integration. Case studies showcase the real-world applications. This synthesis underlines the imperative for collaborative efforts across climatology, engineering, and policy domains. The insights garnered guide future research in optimizing hybrid configurations, thus fostering climate resilience and propelling sustainable energy advancements.