Dish Stirling technology: A 100 MW solar power plant using hydrogen for Algeria

In Algeria, the electricity demand is rapidly increasing. At the same time, Algeria is very rich in solar energy resources and possesses large wasteland areas in the Sahara that represent 80% of the total area and the market of solar energy is very promising. All these indicators make Algeria an ideal country for the implementation of the Concentrating Solar Thermal Power Plant technologies (CSTPP). In order to study whether the implementation of CSTPP under Algerian climate is economically feasible, we present in this article a techno economic assessment of 100 MW of CSTPP based on Dish Stirling technology using hydrogen as working fluid for centralized electricity production located in three typical sites of each geographical regions of Algeria (Algiers, In Salah and Tamanrasset). The National Renewable Energy Laboratory’s SAM software (Solar Advisor Model) is used to evaluate the monthly energy production, annual energy output and the Levelized cost of energy (LCOE) for this study. The results indicate that Tamanrasset is the suitable site yielding the lower LCOE (11.5 c$/kWh) and the higher annual net electric energy output (221 GWh/y).     

An integrated system of zinc oxide solar panels,fuel cells,and hydrogen storage for heating and cooling applications

Due to the production of hydrogen, using fuel cells for energy conversion and storing encounters safety problems. Combining high-temperature solid oxide fuel cells with photovoltaic solar panels or zinc oxide solar panels can be a good candidate to produce/convert and store the energy more efficiently for using at peak times. The current paper intends to analyze the efficiency of integration of zinc oxide solar panels and fuel cells to produce hydrogen directly. Therefore, the excess step of converting electricity to hydrogen and re-converting it to electricity, which is customarily used for the integration of the photovoltaic and solid oxide fuel cells, could be skipped. The new method paves the way for providing the required energy for heating/cooling through the floor heating and ceiling cooling systems as well as generating electricity. The article also demonstrates that it is possible to have heat during the day and night for an area of 1920 m² and 542 m². It is also possible to create coolness during the day and night for an area of 925 m² and 260 m².     

Conceptual design and optimization of a general aviation aircraft with fuel cells and hydrogen

In this paper¹, an aircraft design from scratch and optimization is carried out to investigate the potentials of using liquid hydrogen and fuel cells in general aviation. The focus is set on finding an efficient aircraft configuration that considers all drive train-related components such as the hydrogen tank, fuel cells, and electric motors as well as passenger seats and cargo hold. The paper starts with the definition of the design requirements and specifications. Following, the baseline design of the aircraft in the Suave tool is presented. This includes making extensions to the Suave tool regarding the compatibility of fuel cells and hydrogen energy networks. Eventually, a multidisciplinary design optimization process of selected design variables together with the design constraints is carried out in Suave. Finally, the design is evaluated in terms of performance and emissions by drawing a comparison with conventional general aviation aircraft.     

Exergy optimization of a novel hydrogen production plant with fuel cell,heat recovery,and MED using NSGAII genetic algorithm

In the current research, 4E analysis and multi-criteria optimization are applied to the poly generation unit for power, heating, refrigeration, and freshwater generation. This system consists of a solid oxide fuel cell (SOFC), multi-effect thermal vapor desalination (MED-TVC), an organic system with ejector refrigeration (OSER), a heat recovery steam generator (HRSG) and a domestic hot water generator. The mathematical simulation is applied to assess the performance of the plant at design conditions and the genetic algorithm finds the optimum operating point with two different scenarios. Parametric analysis and multi-objective optimization are carried out. Findings represent that the developed plant can provide 257.65 kW power, 12.13 kW, 7.44 kW cooling and heating load, and 0.04 kg/s freshwater with a total cost rate of 10.62 $/h. In this case, the plant energy and exergy efficiency is 73.9% and 71.35% respectively. The results of multi-objective optimization show that these values can be improved to 79% and 73.9% respectively. In addition, the plant cost can be reached to 10.07 $/h in this condition.     

Size optimization of a hybrid photovoltaic/fuel cell grid connected power system including hydrogen storage

This paper describes the size optimization of a hybrid photovoltaic/fuel cell grid linked power system including hydrogen storage. The overall objective is the optimal sizing of a hybrid power system to satisfy the load demand of a university laboratory with an unreliable grid, with low energy cost and minimal carbon emissions. The aim is to shift from grid linked diesel power system to a clean and sustainable energy system. The optimum design architecture was established by adopting the energy-balance methods of HOMER (hybrid optimization model for electric renewables). Analysis of hourly simulations was performed to decide the optimal size, cost and performance of the hybrid system, using 22-years monthly averaged solar radiation data collected for Ambrose Alli University, Ekpoma (Lat. 6°44.3ʹN, Long. 6°4.8ʹE). The results showed that a hybrid system comprising 54.7 kW photovoltaic array, 7 kW fuel cell system, 14 kW power inverter and 3 kW electrolyzer with 8 kg hydrogen storage tank can sustainably augment the erratic grid with a very high renewable fraction of 96.7% at $0.0418/kWh. When compared with the conventional usage of grid/diesel generator system; energy cost saving of more than 88% and a return on investment of 41.3% with present worth of $308,965 can be derived in less than 3 years. The application of the optimally sized hybrid system would possibly help mitigate the rural-to-urban drift and resolve the electricity problems hindering the economic growth in Nigeria. Moreover, the hybrid system can alleviate CO₂ emissions from other power generation sources to make the environment cleaner and more eco-friendly.     

Simulation and optimization of a stand-alone power plant based on renewable energy sources

By using the optimization software tool HOMER, this project aims at the energetic and economical optimization of a RES-based stand-alone system, already installed at Leicestershire, UK. Based on local meteorological data, an optimization strategy has been developed to identify the most economical and efficient scenarios for the generation of electricity to cover the desirable load in annual basis. Furthermore, the environmental-friendly character of the system was highly concerned in terms of emissions reduction, therefore the capability of an off-grid system was also investigated. The simulations show that an off-grid project with zero emissions is feasible, presenting the additional advantage of minimal capital investment costs. Finally, it is found that grid connection corresponds to very high operational costs in a long term.     

Performance assessment of concentrated solar power plants based on carbon and hydrogen fuel cells

In spite of the recent success on the implementation of Concentrating Solar Power (CSP), still this technology needs a substantial enhancement to achieve competitiveness. This paper provides thorough insight after previous analyses on an alternative concept for higher efficiency CSP systems based on the replacement of the power block by an electrochemical conversion system. Concentrating solar energy is herewith used to decompose methane into hydrogen and carbon, which are used in hydrogen and carbon fuel cells for electricity generation. This approach envisages modular, efficient and flexible generation plants. Dispatchability can be achieved by storing the solid carbon. Solar-to-electricity efficiency was calculated assuming thermodynamic equilibrium composition and experimental data available from literature, and compared with those of conventional power generation systems and commercial CSP plants. It is concluded that this new-generation CSP concept is potentially able to produce power more efficiently than the current state-of-the art solar thermal power plants.     

Current status of combined systems using alkaline fuel cells and ammonia as a hydrogen carrier

In order to solve the hydrogen storage problem ammonia is considered as a storage compound. Hydrogen is supplied by a cracking process. According to equilibrium conditions traces of ammonia are expected, which are known to negatively affect PEM-based fuel cells. Experiments with alkaline fuel cells were carried out. No negative effects on the cell performance were found, when the feed gas contained low concentrations of ammonia.     

Efficiencies of hydrogen storage systems onboard fuel cell vehicles

Energy efficiency, vehicle weight, driving range, and fuel economy are compared among fuel cell vehicles (FCV) with different types of fuel storage and battery-powered electric vehicles. Three options for onboard fuel storage are examined and compared in order to evaluate the most energy efficient option of storing fuel in fuel cell vehicles: compressed hydrogen gas storage, metal hydride storage, and onboard reformer of methanol. Solar energy is considered the primary source for fair comparison of efficiencies for true zero emission vehicles. Component efficiencies are from the literature. The battery powered electric vehicle has the highest efficiency of conversion from solar energy for a driving range of 300 miles. Among the fuel cell vehicles, the most efficient is the vehicle with onboard compressed hydrogen storage. The compressed gas FCV is also the leader in four other categories: vehicle weight for a given range, driving range for a given weight, efficiency starting with fossil fuels, and miles per gallon equivalent (about equal to a hybrid electric) on urban and highway driving cycles.     

Alkaline fuel cell: A test plant,measurements and analysis of the results

An experimental study of an alkaline fuel cell test plant with a 0.5 kW fuel cell module is presented in this paper. The characteristics of the fuel cell module are measured in different steady state load conditions and with different electrolyte temperatures. The results are analysed by calculating the different efficiencies of the module.     

Economics of hydrogen production and utilization strategies for the optimal operation of a grid-parallel PEM fuel cell power plant

This paper integrates the hydrogen production and utilization strategies with an economic model of a PEM fuel cell power plant (FCPP). The model includes the operational cost, thermal recovery, power trade with the local grid, and hydrogen management strategies. The model is used to determine the optimal operational strategy, which yields the minimum operating cost. The optimal operational strategy is achieved through estimation of the following: hourly generated power, thermal power recovered from the FCPP, power trade with the local grid, and hydrogen production. An evolutionary programming-based technique is used to solve for the optimal operational strategy. The model is tested using different seasonal load demands. The results illustrate the impact of hydrogen management strategies on the operational cost of the FCPP when subjected to seasonal load variation. Results are encouraging and indicate viability of the proposed model.     

Assessment and optimization of an integrated energy system with electrolysis and fuel cells for electricity,cooling and hydrogen production using various optimization techniques

In this research study, a novel integrated solar based combined, cooling, heating and, power (CCHP) is proposed consisting of Parabolic trough solar collectors (PTSC) field, a dual-tank molten salt heat storage, an Organic Rankine Cycle (ORC), a Proton exchange membrane fuel cell (PEMFC), a Proton exchange membrane electrolyzer (PEME), and a single effect Li/Br water absorption chiller. Thermodynamics and economic relations are used to analyze the proposed CCHP system. The mean of Tehran solar radiation as well as each portion of solar radiation during 24 h in winter is obtained from TRNSYS software to be used in PTSC calculations. A dynamic model of the thermal storage unit is assessed for proposed CCHP system under three different conditions (i.e., without thermal energy storage (TES), with TES and with TES + PEMFC). The results demonstrate that PEMFC has the ability to improve the power output by 10% during the night and 3% at sunny hours while by using TES alone, the overnight power generation is 86% of the power generation during the sunny hours. The optimum operating condition is determined via the NSGA-II algorithm with regards to exergy efficiency and total cost rate as objective functions where the optimum values are 0.058 ($/s) and 80%, respectively. The result of single objective optimization is 0.044 ($/s) for the economic objective in which the exergy efficiency is at its lowest value (57.7%). In addition, results indicate that the amount of single objective optimization based on exergetic objective is 88% in which the total cost rate is at its highest value (0.086 $/s). The scattered distribution of design parameters and the decision variables trend are investigated. In the next step, five different evolutionary algorithms namely NSGA-II, GDE3, IBEA, SMPSO, and SPEA2 are applied, and their Pareto frontiers are compared with each other.     

Transient simulation and comparative assessment of a hydrogen production and storage system with solar and wind energy using TRNSYS

This paper uses the TRNSYS software to investigate the hourly energy generation potential, storage, and consumption via an electrolyzer and a fuel cell in the Canadian city of Saskatoon, which is a region with high solar and wind energy potential. For this purpose, a location with an area of 10,000 m² was considered, in which the use of solar panels and vertical-axis wind turbines (VAWTs) were simulated. In the simulation, the solar panels were placed at specific distances, and the energy generation capacity, amount of produced hydrogen, and the energy available from the fuel cell were examined hourly and compared to the case with wind turbines placed at standard distances. The results indicated energy generation capacities of 1,966,084 kWh and 75,900 kWh for the solar panels and the wind turbines, respectively, showing the high potential of solar panels compared to wind turbines. Moreover, the fuel cells in the solar and wind systems can produce 733,077 kWh and 22,629 kWh of energy per year, respectively, if they store all of the received energy in the form of hydrogen. Finally, the hourly rates of hydrogen production by the solar and wind systems were reported.     

Off-grid solar powered charging station for electric and hydrogen vehicles including fuel cell and hydrogen storage

This paper designs an off-grid charging station for electric and hydrogen vehicles. Both the electric and hydrogen vehicles are charged at the same time. They appear as two electrical and hydrogen load demand on the charging station and the charging station is powered by solar panels. The output power of solar system is separated into two parts. On part of solar power is used to supply the electrical load demand (to charge the electric vehicles) and rest runs water electrolyzer and it will be converted to the hydrogen. The hydrogen is stored and it supplies the hydrogen load demand (to charge the hydrogen-burning vehicles). The uncertainty of parameters (solar energy, consumed power by electrical vehicles, and consumed power by hydrogen vehicles) is included and modeled. The fuel cell is added to the charging station to deal with such uncertainty. The fuel cell runs on hydrogen and produces electrical energy to supply electrical loading under uncertainties. The diesel generator is also added to the charging station as a supplementary generation. The problem is modeled as stochastic optimization programming and minimizes the investment and operational costs of solar and diesel systems. The introduced planning finds optimal rated powers of solar system and diesel generator, operation pattern for diesel generator and fuel cell, and the stored hydrogen. The results confirm that the cost of changing station is covered by investment cost of solar system (95%), operational cost of diesel generator (4.5%), and investment cost of diesel generator (0.5%). The fuel cell and diesel generator supply the load demand when the solar energy is zero. About 97% of solar energy will be converted to hydrogen and stored. The optimal operation of diesel generator reduces the cost approximately 15%.     

Architecture design and performance analysis of a hybrid hydrogen fuel cell system for unmanned aerial vehicle

The flight endurance of UAV systems is an important issue that restricts the operational capabilities. Thus, different energy systems and alternative onboard energy generation systems have been tested for the UAVs. Within these systems, fuel cells provide high energy density that can increase flight endurance greatly. In this study, a PEM fuel cell – Li-Po battery hybrid system has been developed by evaluating three architecture models. In the guide of the experimental power demand data of a fixed-wing UAV, modeling and testing procedures were performed. Battery voltage and fuel cell current variations observed during the ground tests were evaluated. It has been observed that approximately 160–170 W of the 250 W power is met by the fuel cell since no preconditioning has been applied and the temperature values at which the fuel cell exhibits its optimum performance. In the case where the fuel cell could provide 7.8 An under conditions where the humidification effects were not included in the model, the required current was over 7.8 A between approximately 400-1200 s. The fuel cell and battery behavior in response to the sudden power changes and to the uncertainties corresponding to the changes in the motor power during the flight are also detailed.     

Electrochemical analysis of hydrogen membrane fuel cells

An electrochemical analysis was conducted with respect to a hydrogen membrane fuel cell with SrZr_0.8In_0.2O_3−δ electrolyte, which is a new type of fuel cell featuring an ultra-thin proton conductor supported on a dense metal anode. Most of the voltage loss derives from the cathode and the electrolyte, and a small amount of anode polarization was observed only in regions with high current density. The cathode polarization was approximately an order of magnitude lower than that of SOFCs. Furthermore, the conductivity of the film electrolyte was almost identical to that of the sinter at 600 °C; however, it was several times as large at 400 °C. A TEM micrograph revealed that the film electrolyte consists mainly of long columnar crystals, and this crystal structure can be related to the conductivity enhancement below 600 °C.     

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.     

Development of a new solar,gasification and fuel cell based integrated plant

Despite its shortcomings, fossil-based fuels are still utilized as the main energy source, accounting for about 80% of the world's total energy supply with about one-third of which comes from coal. However, conventional coal-fired power plants emit relatively higher amounts of greenhouse gases, and the derivatives of air pollutants, which necessitates the integration of environmentally benign technologies into the conventional power plants. In the current study, a H₂–CO synthesis gas fueled solid oxide fuel cell (SOFC) is integrated to the coal-fired combined cycle along with a concentrated solar energy system for the purpose of promoting the cleaner energy applications in the fossil fuel-based power plants. The underlying motivation of the present study is to propose a novel design for a conventional coal-fired combined cycle without altering its main infrastructure to make its environmentally hazardous nature more ecofriendly. The proposed SOFC integrated coal-fired combined cycle is modeled thermodynamically for different types of coals, namely pet coke, Powder River Basin (PRB) coal, lignite and anthracite using the Engineering Equation Solver (EES) and the Ebsilon software packages. The current results show that the designed hybrid energy system provide higher performance with higher energy and exergy efficiencies ranging from 70.6% to 72.7% energetically and from 35.5% to 43.8% exergetically. In addition, carbon dioxide emissions are reduced varying between 18.31 kg/s and 30.09 kg/s depending on the selected coal type, under the assumption of 10 kg per second fuel inlet.