Steady-state modelling of hybrid energy system for off grid electrification of cluster of villages

Electrification of villages from the main grid leads to large investments and losses, and this forms the basis of decentralized Hybrid Energy System. In order to evaluate the techno-economic performance of hybrid energy system for remote rural area electrification, a mixed integer linear mathematical programming model (time-series) has been developed to determine the optimal operation, optimal configuration including the assessment of the economic penetration levels of photovoltaic array area, and cost optimization for a hybrid energy generation system consisting of small/micro hydro based power generation, biogas based power generation, biomass (fuelwood) based power generation, photovoltaic array, a battery bank and a fossil fuel generator. An optimum control algorithm written in C++, based on combined dispatch strategy, allowing easy handling of the models and data of hybrid energy system components is presented. A special feature of the proposed model is that a cost constant (cost/unit) for each of the proposed resource is introduced in the cost objective function in such a way that resources with lesser unit cost share the greater of the total energy demand in an attempt to optimize the objective function.To demonstrate the use of model and algorithm, a case study for a rural remote area is also presented.     

A demonstrative study for the wind and solar hybrid power system

In March 1995, a small scale wind and solar hybrid power system was installed at Ashikaga Institute of Technology. Until now, the authors have acquired the data of the output of the hybrid power plant along with wind speed, wind direction, and the solar radiation, in order to demonstrate a complementary relationship between solar energy and wind energy.After nine months operation of the system, the authors confirmed that there exists a complementary relationship between solar energy and wind energy. We also found, however, that the power output by wind does not have much prospect compared to that by solar cell especially in summer season in Ashikaga area.     

The 10 years operation of a PV-micro-hydro hybrid system in Taratak, Indonesia

A 48–71.1 kWp photovoltaic-micro-hydro system has been installed at Taratak, Indonesia since June 10, 1989. The system is being developed in Indonesia to obtain optimal result by combining the advantages of both energy conversion systems. The photovoltaic works as a dominant part in this hybrid system. However, the micro-hydro sub-system works to compensate the inconvenience found in the photovoltaic. It will anticipate the weather uncertainty and fulfill the need during the peak load. In this paper we analyze and evaluate the performance of a PV-micro-hydro (PV-MH) system in Taratak. We find the difference between the initial design and the actual system operation. Results of the evaluation show that the performance of PV-MH system operation is still optimal.     

Review on recent optimization strategies for hybrid renewable energy system with hydrogen technologies: State of the art,trends and future directions

The world is currently facing a power shortage due to the inadequacy of conventional energy sources and increased energy requirements in almost all sectors of human life. To mitigate this issue, the researchers have taken the considerable interest of researchers over the past decade in enhancing energy efficiency and viability. A hybrid renewable energy system (HRES) can efficiently produce clean energy to meet energy demand. Thus, it is extensively employed to improve power system quality, reliability, and economy, rather than solely relying on non-renewable energy sources. Nevertheless, RE sources' uncertain and intermittent nature, like wind speed and solar radiation, is associated with HRES. This problem can be solved with proper optimization by coupling HRES with energy conversion and storage devices, e.g., electrolyzer, fuel cell, and hydrogen tank, which can admirably balance power generation and energy demand. The literature is rich in employing optimization techniques on HRES with hydrogen technologies (HRES-H₂). However, a gap is found in the overall research progress of optimization approaches, considering HRES coupled with H₂ equipment. Therefore, the current study comprehensively reviews all the optimization approaches applied in this field worldwide. Further, a text mining-based software VOSviewer is used to investigate the scientific landscape of the literature body to figure out the current trends and future scope of HRES-H₂. It has been investigated that the researchers are focusing on: techno-economic optimization of HRES-H₂, developing sophisticated hydrogen infrastructure to reduce the overall cost of hydrogen fuel, introducing AI-based multi-objective optimization techniques to make the HRES-H₂ system more reliable and economically viable, and the impact of renewable and hydrogen technologies on the reduction of global warming. Lastly, an insightful of the current review highlighting the present shortcomings and opportunities of clean energy and hydrogen has been discussed, and suggestions are provided.     

Design of hybrid power-to-power systems for continuous clean PV-based energy supply

The increasing penetration of intermittent renewable sources, fostering power sector decarbonization, calls for the adoption of energy storage systems as an essential mean to improve local electricity exploitation, reducing the impact of distributed power generation on the electric grid. This work compares the use of hydrogen-based Power-to-Power systems, battery systems and hybrid hydrogen-battery systems to supply a constant 1 MW_el load with electricity locally generated by a photovoltaic plant. A techno-economic optimization model is set up that optimizes the size and annual operation of the system components (photovoltaic field, electrolyzer, hydrogen storage tanks, fuel cell and batteries) with the objective of minimizing the annual average cost of electricity, while guaranteeing an imposed share of local renewable self-generation. Results show that, with the present values of investment costs and grid electricity prices, the installation of an energy storage system is not economically attractive by itself, whereas the installation of PV panels is beneficial in terms of costs, so that the baseline optimal solution consists of a 4.2 MW_p solar field capable to self-generate 33% of the load annually. For imposed shares of self-generation above 40%, decoupling generation and consumption becomes necessary. The use of batteries is slightly less expensive than the use of hydrogen storage systems up to a 92% self-generation rate. Above this threshold, seasonal storage becomes predominant and hybrid storage becomes cheaper than batteries. The sale of excess electricity is always important to support the plant economics, and a sale price reduction sensibly impacts the results. Hydrogen storage becomes more competitive when the need for medium and long terms energy shift increases, e.g. in case of having a cap on the available PV capacity.     

A mobile renewable house using PV/wind/fuel cell hybrid power system

A photovoltaic/wind/fuel cell hybrid power system for stand-alone applications is proposed and demonstrated with a mobile house. This concept shows that different renewable sources can be used simultaneously to power off-grid applications. The presented mobile house can produce sufficient power to cover the peak load. Photovoltaic and wind energy are used as primary sources and a fuel cell as backup power for the system. The power budgeting of the system is designed based on the local data of solar radiation and wind availability. Further research will focus on the development of the data acquisition system and the implementation of automatic controls for power management.     

Experimental investigation of power management and control of a PV/wind/fuel cell/battery hybrid energy system microgrid

This paper presents an experimental study of a standalone hybrid microgrid system. The latter is dedicated to remote area applications. The system is a compound that utilizes renewable sources that are Wind Generator (WG), Solar Array (SA), Fuel Cell (FC) and Energy Storage System (ESS) using a battery. The power electronic converters play a very important role in the system; they optimize the control and energy management techniques of the various sources. For wind and solar subsystem, the speed and Single Input Fuzzy Logic (SIFL) controllers are used respectively to harvest the maximum power point tracking (MPPT). To maintain a balance of energy in the hybrid system, an energy management strategy based on the battery state of charge (SOC) has been developed and implemented experimentally. The AC output voltage regulation was achieved using a Proportional Integral (PI) controller to supply a resistive load with constant amplitude and frequency. According to the obtained performances, it was concluded that the proposed system is very promising for potential applications in hybrid renewable energy management systems.     

Design and feasibility analysis of hydrogen based hybrid energy system: A case study

Renewable energy sources can produce less carbon than conventional energy sources, which has the significant disadvantage of being intermittent, which triggers a stable storage system. This work focuses on the issues of hydrogen energy storage which can solve the fluctuating output power problem by simulating results on HOMER software. Three combinations of the Solar-Hydrogen system, Wind-Hydrogen system, and Solar-Wind-Hydrogen hybrid system are presented to find the most optimum one. Levelized Cost of Energy (LCOE) for Hybrid System has proven to be the most economical while the Wind Turbine cost 1.476% higher and the Solar Photovoltaics (PV) System costs 108.03% more. LCOE for Hybrid Model is $0.3387, while for Solar System it is $ 0.7046 and for Wind System it is $ 0.3437. These results show that a hydrogen-based energy storage system is viable for the considered.     

Simulation of a small wind fuel cell hybrid energy system

This paper describes simulation results of a small 500 W wind fuel cell hybrid energy system. The system consists of a Southwest Wind Power Inc. AIR 403 wind turbine, a Proton Exchange Membrane Fuel Cell (PEMFC) and an electrolyzer. Dynamic modeling of various components of this small isolated system is presented. Simulink is used for the dynamic simulation of this nonlinear 48 V hybrid energy system. Transient responses of the system to a step change in the load current and wind speed in a number of possible situations are presented. Analysis of simulation results and limitations of a wind fuel cell hybrid energy system are discussed.     

Performance evaluation of hybrid PV/thermal water/air heating system: A parametric study

In this paper, a thermal model of an integrated photovoltaic and thermal solar (IPVTS) water/air heating system has been developed. An analytical expression for the temperature of solar cell and water and an overall thermal efficiency of IPVTS system have been derived as a function of climatic and design parameters. Numerical computations have been carried out for composite climate of New Delhi for parametric studies. Four configurations, namely (a) unglazed with tedlar (UGT), (b) glazed with tedlar (GT), (c) unglazed without tedlar (UGWT) and (d) glazed without tedlar (GWT) have been considered. Comparison of the IPVTS system with water and air heater has also been carried out. It is found that the characteristic daily efficiency of IPVTS system with water is higher than with air for all configurations except GWT. It is also observed that an overall thermal efficiency of IPVTS system for summer and winter conditions is about 65% and 77%, respectively.     

Modeling and control of a wind fuel cell hybrid energy system

This paper describes a hybrid energy system consisting of a 5 kW wind turbine and a fuel cell system. Such a system is expected to be a more efficient, zero emission alternative to wind diesel system. Dynamic modeling of various components of this isolated system is presented. Selection of control strategies and design of controllers for the system is described. Simnon is used for the simulation of this highly nonlinear system. Transient responses of the system for a step change in the electrical load and wind speed are presented. System simulation results for a pre-recorded wind speed data indicates the transients expected in such a system. Design, modeling, control and limitations of a wind fuel cell hybrid energy system are discussed.     

Effect of wind energy system performance on optimal renewable energy model-an analysis

The Optimal Renewable Energy Model (OREM) has been developed to determine the optimum level of renewable energy sources utilisation in India for the year 2020–21. The model aims at minimising costefficiency ratio and determines the optimum allocation of different renewable energy sources for various end-uses. The extent of social acceptance level, potential limit, demand and reliability will decide the renewable energy distribution pattern and are hence used as constraints in the model. In this paper, the performance and reliability of wind energy system and its effects on OREM model has been analysed. The demonstration windfarm (4 MW) which is situated in Muppandal, a village in the southern part of India, has been selected for the study. The windfarm has 20 wind turbine machines of 200 KW capacity. The average technical availability, real availability and capacity factor have been analysed from 1991 to 1995 and they are found to be 94.1%, 76.4% and 25.5% respectively. The reliability factor of wind energy system is found to be 0.5 at 10,000 hours. The OREM model is analysed considering the above said factors for wind energy system, solar energy system and biomass energy systems. The model selects wind energy for pumping end-use to an extent of 0.3153×10¹⁵ KJ.     

Design and analysis of stand-alone hydrogen energy systems with different renewable sources

One of the most interesting developments of energy systems based on the utilization of hydrogen is their integration with renewable sources of energy (RES). In fact, hydrogen can operate as a storage and carrying medium of these primary sources. The design and operation of the system could change noticeably, depending on the type and availability of the primary source. In this paper, the results obtained considering a model of a stand-alone energy system supplied just with RES and composed by an electrolyzer, a hydrogen tank and a proton exchange membrane fuel cell are exposed. The energy systems have been designed in order to supply the electricity needs of a residential user in a mountain environment in Italy during a complete year. Three different sources have been considered: solar irradiance (transformed by an array of photovoltaic modules), hydraulic energy (transformed by a micro-hydro turbine in open-flume configuration) and wind speed (transformed by a small-size wind generator). It has been checked that, in that specific location, it is absolutely not convenient to use the wind source; the solar irradiance has a nearly constant availability during the year, and therefore the seasonal storage of the RES in form of hydrogen is the lowest; the availability of the micro-hydro source is less constant than in case of solar irradiance, requiring a higher hydrogen seasonal storage, but its advantage is linked to the higher efficiency of the turbine and the fact that the RES is directly sent to the user with high frequency (for these reasons it is the best plant option).     

Technoeconomic optimization of a hybrid solar air-heating system

This paper presents a simple techno-economic model for a hybrid solar air-heating system based on water as the storage medium. The configuration of the system consists of a conventional solar air-heater, water tank for thermal storage, a unit which adjusts the higher air temperature (during peak sunshine hours) to the required limit (by mixing fresh air) and an arrangement for providing auxiliary energy if and when required. A thermostatically controlled electric heater is assumed to be the source of auxiliary energy, in the present calculations. In order to evaluate the performance of the system using the developed model numerical calculations have been made corresponding to the climate of Delhi, India. The calculations have been extended to obtain the optimized values of collector area and storage mass which correspond to the minimum value of useful energy. Numerical results show that the cost of useful energy obtained for optimized values of collector area and storage mass is much less than the cost of electrical heating.     

Performance analysis of a hybrid solar-hydrogen-retired EV batteries (REVB) energy system with thermal-electrical loops

Utilizing solar energy is an efficient method to provide hybrid renewable energy system with sufficient thermal/electrical energy. Meanwhile, the rapid development of electrical vehicles leads to an excess of retired electric vehicles. As a combination of the abovementioned two conceptions, this study proposed and examined a hybrid solar-hydrogen-retired electrical vehicle battery energy system to meet thermal and electrical loads for small-scale usage. The novelty of this research is delivered as follows: first of all, the proposed hybrid energy system supplies both thermal and electrical energy to small-scale end users; secondly, the retired electrical vehicle batteries are recycling to relieve the pressure of battery demand; thirdly, an energy management strategy to regulate the complicated hybrid energy system is designed. The results show that with assistance of fuel cell as an energy storage unit, solar energy can basically satisfy the annual thermal/electrical load with maximum monthly energy supplement of 1220.43 MJ and 1572.75 kWh, respectively. However, the solar radiation serving as single energy source is not very reliable for large-scale utilization. Although the state of charge does not fluctuate greatly, the small range charge/discharge between 59% and 63% can still guarantee the normal operation of the proposed hybrid energy system.     

Triple hybrid system coupling fuel cell with wind turbine and thermal solar system

One of the most challenging issues in the domain of renewable energy is the instability of produced power. To put it another way, renewable resources such as solar energy cannot provide continuous energy supply because they rely on natural phenomena that vary randomly. That said, to cover the potential lack of energy that may occur, hybrid renewable energy system can be adopted. In other terms, instead of using single renewable energy source, two different sources can be utilized in order to optimize the output power all over the year. Furthermore, complementary energy system is needed along with renewable sources, to store energy and insure the supply during shortage period. With this in mind, a Green-Green energy system can be constructed by using green storage system such as Fuel Cell to be coupled with the renewable sources. In the light of green-green energy concept, the present paper examines a triple wind-solar-fuel cell combination in the aim of overcoming the energy shortage that occurs during several months of the year. A case study on the region of Dahr Al-Baidar in Lebanon is conducted to present the advantage of the proposed system. Results show that combining wind energy system with thermal solar system allows overcoming the low power produced by solar thermal system especially in winter. For illustration 16 kW are produced by wind turbine during the month of January, by contrast the thermal solar system provides 2 kW during the same period. Nevertheless, in June thermal solar offers 17 kW and wind turbine produces 11 kW.     

Assessing the lifecycle greenhouse gas emissions from solar PV and wind energy: A critical meta-survey

This paper critically screens 153 lifecycle studies covering a broad range of wind and solar photovoltaic (PV) electricity generation technologies to identify 41 of the most relevant, recent, rigorous, original, and complete assessments so that the dynamics of their greenhouse gas (GHG) emissions profiles can be determined. When viewed in a holistic manner, including initial materials extraction, manufacturing, use and disposal/decommissioning, these 41 studies show that both wind and solar systems are directly tied to and responsible for GHG emissions. They are thus not actually emissions free technologies. Moreover, by spotlighting the lifecycle stages and physical characteristics of these technologies that are most responsible for emissions, improvements can be made to lower their carbon footprint. As such, through in-depth examination of the results of these studies and the variations therein, this article uncovers best practices in wind and solar design and deployment that can better inform climate change mitigation efforts in the electricity sector.     

风光混合发电系统发电量的计算模型

本文介绍了风光混合发电系统风力发电量和光伏发电量的计算模型,提出了风频分布的规律和不同倾角倾斜面上辐射量的计算方法。     

Study of hybrid energy system coupling fuel cell,solar thermal system and photovoltaic cell

The present work examines the combination of solar energy systems with Fuel cell. Indeed, fuel cells are green storage systems without any pollution effects. They are supplied by oxygen and hydrogen to produce electricity. That is why it is inescapable to find a source of hydrogen in order to use fuel cell. Several techniques can be adopted to produce hydrogen depending on the availability and the cost of the sources. One of the most utilized techniques is electrolysers. They allow to obtain hydrogen from water by several technologies among them proton exchange membrane (PEM) which is considered in this work. On the other hand, electrolysers need electrical power to operate. A green-green energy system can be constructed by using a renewable energy source to supply fuel cell trough electrolysers. A comparison between two solar systems (Photovoltaic and Parabolic Trough) coupled to fuel cell is performed. A case study on the Lebanese city of Tripoli is carried out. The study shows the performance of each of both combined systems for different parameters and proposes recommendations depending on the considered configuration.     

An application of a combined wind and solar energy system in Izmir

In this work, a combined system which is produced electrical energy from both solar radiation via solar cells and wind energy by using wind turbine was studied. For wind energy, measurements of wind velocities at 12 m height were taken. Then, these values were calculated for 42 m by using Hellmann equation. After that, wind energy converted to the electrical energy. However, value of solar radiation from solar cells was taken at the optimum slope angle of collector which provided higher energy production for each 1 h during this application. Thus, obtained data from each system were used together for finding total energy. For this study, measurements, which would be used in calculation of wind energy and solar energy were taken for four years between 1995 and 1998 in Izmir. As a result, energy of the combined system could support each other when one of them produces energy insufficiently.