Solid Oxide Fuel Cell Technology Research Articles

Surface functionalizing for high‐temperature ceramic fuel cells using electrochemical deposition technique

AbstractElectrochemical deposition technique, a method widely recognized for its precision and versatility in the electronics industry, is gaining attraction in the energy field, particularly in developing solid oxide fuel cells (SOFCs). Its ability to deposit metal compounds with nanostructures under simple ambient conditions makes it invaluable for modifying conventional electrodes with refined morphologies and compositions. In this mini‐review, we explore the principles of electrochemical deposition and highlight its recent applications in SOFC technology. Our focus lies on its pivotal role in fabricating coating layers or catalysts on electrodes with improved functionalities to build more efficient and durable fuel cells. Furthermore, we discuss emerging strategies for electrode surface modification and the potential of electrochemical deposition in advancing SOFC design and functionality. Our review also outlines future research directions aimed at harnessing and expanding the capabilities of electrochemical deposition in energy conversion applications.

Metaheuristic optimizing energy recovery from plastic waste in a gasification-based system for waste conversion and management

In an era where sustainable waste management and clean energy production are paramount, this study presents an innovative integration of plastic waste gasification with solid oxide fuel cell (SOFC) technology, optimized through metaheuristic particle swarm optimization (PSO). The research explores the conversion of polypropylene (PP) waste into syngas via gasification, which is then utilized as a fuel for SOFCs to generate electricity. The optimization process focuses on maximizing power and heating outputs while minimizing carbon dioxide emissions. The study's findings demonstrate the potential of integrating gasification and SOFC technologies to create a sustainable energy system that addresses the challenges of plastic waste. Key findings from the metaheuristic PSO multi-objective optimization reveal that optimal power production, approximately 360 kW, is achieved at temperatures exceeding 1140 K, irrespective of the steam/PP waste ratio. Heating production peaks at 1000 kW with temperatures above 1120 K and utilization factors over 0.765, while the minimum heating output is 700 kW. Emission analysis indicates a significant reduction in carbon dioxide emissions with increased temperatures and utilization factors, achieving a minimum of 700 kg/MWh at temperatures above 1120 K. The study's results demonstrate the effectiveness of the PSO optimization in fine-tuning the operational parameters of the integrated system, leading to improved energy efficiency and reduced environmental impact. Power production of 366.37 kW, a significant heating rate of 995.20 g/s, and emissions of 714.06 kg/MWh are the optimum performances. The research provides valuable insights into the potential of plastic waste-to-energy technologies as sustainable solutions for energy production and waste management.

Advancements in Solid Oxide Fuel Cell Technology: Bridging Performance Gaps for Enhanced Environmental Sustainability

In light of the anticipated 50% increase in global energy demand by 2050, the demand for innovative, environmentally conscious, efficient, and dependable energy technologies is paramount. Solid oxide fuel cells (SOFCs) offer a promising solution for sustainable energy production. This comprehensive review provides a detailed analysis of SOFCs, covering their fundamentals, materials, performance, and diverse applications, while also addressing technological challenges and future prospects. The review emphasizes the key advantages of SOFCs, including their high efficiency of up to 60% and minimal environmental impact. It explores the significance of impurity resistance and durability in materials and manufacturing processes for SOFC components. Comparative evaluations demonstrate the superior energy efficiency and ecological effects of SOFCs compared to other fuel cell technologies. SOFCs’ versatility and potential are showcased through their applications in transportation, power generation and storage, portable devices, and residential usage. However, challenges such as cost, longevity, reliability, and integration with other energy systems are identified, emphasizing the need for supportive policies and regulations.

Exploring novel nanostructural architecture of doubly doped ceria (Ce0.85Sr0.075Sm0.075O2-δ) and barium cerate (BaCeO3) as electrolytes for low-temperature solid oxide fuel cells

This study presents the development of a composite electrolyte for use in low-temperature (300–500 °C) Solid oxide Fuel Cells, focusing on a novel nanostructural design. The electrolyte comprises co-doped ceria (Ce0.85Sr0.075Sm0.075O2-δ, DCO) and barium cerate (BaCeO3, BCO), integrated into a unique nanostructural architecture. Initially, the constituent phases of the composite DCO and BCO are synthesized using a soft-chemical route separately, followed by their integration through liquid mixing technique in various compositions (90:10, 80:20, 70:30, 60:40, 50:50) of DCO:BCO in weight ratio. The composite structure is confirmed by X-ray diffraction, and refined the structural data by Rietveld refinement indicating a structural agreement with cubic and fluorite phases of DCO and BCO, respectively. Scanning Electron microscopy (SEM) and Energy Dispersive X-ray Analysis (EDAX) reveal a uniform distribution of two phases with fine size distribution below 50 nm. Transmission Electron microscopy (TEM) images illustrate the core-shell-like integration of the two phases. High-resolution TEM images indicate that the core consists of the DCO phase, while the shell is composed of the BCO phase. The microstructure of sintered pellets exhibits gas-tight densification, with grains dominated by the DCO phase and BCO phase dispersed along grain boundaries. The ionic conductivity of composite systems is extracted from Electrochemical impedance spectroscopy (EIS) studies, showing that DCO-BCO-40 exhibits the highest conductivity 1.132 × 10−3 Scm−1 @400 °C, which is higher than pristine DCO (0.34 × 10−4 Scm−1 @400 °C). Single cells fabricated using DCO-BCO-40 electrolytes deliver a power output of 280 mW cm−2 whereas pristine DCO showed 279 mW @500 °C. This study exhibits the potential of the core-shell-like nanostructural architecture of electrolytes in advancing Low-temperature solid oxide Fuel cell (LT-SOFC) technology and facilitating the transition toward sustainable energy systems.

Sn-doped cobalt containing perovskite as the cathode for highly active SOFCs

One potential solution to the challenges of energy storage and conversion is the utilization of solid oxide fuel cells (SOFCs), which offer a versatile pathway for the generation of renewable fuels. However, the advancement of SOFC technology faces significant obstacles, including sluggish oxygen reaction kinetics, insufficient durability, and poor round-trip efficiency, primarily due to the limitations of the air electrode. To address these challenges, we present a novel Sn doped cathode BaCo0.4Fe0.5-xSnxYb0.1O3−δ (BCFSYx), designed to enhance electrochemical performance at lower temperatures. The finding demonstrates that BaCo0.4Fe0.425Sn0.075Yb0.1O3-δ (BCFSY075) displays favorable oxygen reduction reaction (ORR) performance and achieves the best power density. Furthermore, the polarization process exhibits a reduced reliance on temperature, hence enabling the potential for consistent operation at low temperatures.

Enriching Nano-Heterointerfaces in Proton Conducting TiO2-SrTiO3@TiO2 Yolk-Shell Electrolyte for Low-Temperature Solid Oxide Fuel Cells.

A challenging task in solid oxide fuel cells (SOFCs) is seeking for an alternative electrolyte, enabling high ionic conduction at relatively low operating temperatures, i.e., 300-600°C. Proton-conducting candidates, in particular, hold a significant promise due to their low transport activation energy to deliver protons. Here, a unique hierarchical TiO2-SrTiO3@TiO2 structure is developed inside an intercalated TiO2-SrTiO3 core as "yolk" decorating densely packed flake TiO2 as shell, creating plentiful nano-heterointerfaces with a continuous TiO2 and SrTiO3 "in-house" interfaces, as well the interfaces between TiO2-SrTiO3 yolk and TiO2 shell. It exhibits a reduced activation energy, down to 0.225eV, and an unexpectedly high proton conductivity at low temperature, e.g., 0.084 S cm-1 at 550°C, confirmed by experimentally H/D isotope method and proton-filtrating membrane measurement. Raman mapping technique identifies the presence of hydrogenated HO─Sr bonds, providing further evidence for proton conduction. And its interfacial conduction is comparatively analyzed with a directly-mixing TiO2-SrTiO3 composite electrolyte. Consequently, a single fuel cell based on the TiO2-SrTiO3@TiO2 heterogeneous electrolyte delivers a good peak power density of 799.7mW cm-2 at 550°C. These findings highlight a dexterous nano-heterointerface design strategy of highly proton-conductive electrolytes at reduced operating temperatures for SOFC technology.

Electrical and electrochemical properties of A-site non-stoichiometry Ca0.67La0.22□0.11Ti(1−x)CrxO3−δ electrolyte materials for solid oxide fuel cells

Due to increasing global energy demands and environmental concerns, the search for alternative and environmentally friendly energy sources is of paramount importance. Solid oxide fuel cells (SOFCs) have emerged as a promising solution thanks to their high efficiency and minimal environmental impact. In this regard, perovskite oxides, with their unique properties, have attracted significant attention. This study investigates the dielectric dispersion, electrical features, scaling behavior, and optical defects of Ca0.67La0.22Ti0.85Cr0.15O3 with x = 0.15, CLT0.85Cr0.15. The presence of a vacancy in the A-site is denoted by the square in the formula. Relaxation phenomena were analysed using dielectric and modulus formalism, while the conductivity mechanism was explored through electrical conductivity measurements. The optical defects of CLT0.85Cr0.15 were analysed using electron paramagnetic resonance (EPR) spectroscopy. The findings revealed the formation of Cr3+–VO center defects. These defects serve as sources of in-gap electron traps, thereby enhancing the optical properties of CLT0.85Cr0.15, making it as a compelling material for various optical applications. The power density increased with temperature, reaching 0.73 W/cm2 at 850 °C, suggesting that CLT0.85Cr0.15 could be a promising electrolyte for IT-SOFCs. The peak in power density correlated with temperature due to thermal effects on ion motion. However, the open circuit voltage decreased with temperature increase, due to increased oxygen vacancies and electron/hole conduction in CLT0.85Cr0.15. The findings suggest that perovskite materials could revolutionize SOFCs technology, paving the way for more efficient and environmentally friendly energy solutions.

Environmental protection and sustainable waste-to-energy scheme through plastic waste gasification in a combined heat and power system

By utilizing plastic waste as a feedstock for gasification and integrating a solid oxide fuel cell, this system has the potential to not only generate electricity and heat efficiently but also reduce environmental pollution by converting waste materials into valuable energy resources. This research explores a combined heat and power system that integrates polystyrene waste gasification with a solid oxide fuel cell technology. The study thoroughly examines and optimizes the system's performance through the application of response surface methodology. Higher steam to plastic waste ratio improves the power production (from 244.1 to 246 kW) and mitigates the emission (from 785.4 to 761.3 kg/MWs). Enhanced power (from 86.25 to 337 kW, representing an impressive improvement of approximately 291 %) and heating (from 172.6 to 275.3 kW, marking a substantial improvement of approximately 59.5 %) are achieved at higher current densities. At a current density of 3200–3600 A/m² and a temperature of 1020–1040 K, the system can achieve 200–240 kW power, 390–450 g/s heating value, and 840–860 kg/MWs emissions. Further optimization at a steam to plastic ratio of 0.95–1.1 and 1030–1040 K temperature can improve performance to 280–300 kW power, 580–600 g/s heating value, and 840–860 kg/MWs emissions. The study provides valuable insights into the potential benefits of integrating plastic waste gasification with solid oxide fuel cell technology, highlighting the importance of sustainable energy solutions in addressing environmental challenges. Moving forward, further research in this area could lead to the development of more efficient and environmentally friendly energy systems.

Synergistic effects and electrocatalytic insight of single-phase hexagonal structure as low-temperature solid oxide fuel cell cathode

Enhancing the electrocatalytic activity of the electrode materials, specifically oxygen reduction reaction (ORR), at lower operating temperatures (<600 °C) is the prime rank to realize the commercialization of solid oxide fuel cells (SOFCs) research. Herein, a new hexagonal structure-based cathode material was developed with the co-doping of Gd2O3 and Cr2O3 of parent SrFe12O19 oxide, respectively. At 550‒475 °C, Sr0.90Gd0.10Fe11.90Cr0.10O19 (SFO-10) cathode sample leading to the large peak power density (PPD) of 395 mW/cm2, has appropriate surface oxygen defects (Oβ) up to 17%, as verified by X-ray photoelectron microscopy (XPS). Theoretical calculations reveal that the co-doping of Gd and Cr oxides creates lattice disorder at the hexagonal lattice, which decreases the energy barrier for ion transport and enhances the electrocatalytic characteristics of ORR. Consequently, the SFO-10 cathode shows a favorable ORR activity with the least lower polarization resistance (ASR) at 550 °C with gadolinium-doped ceria (GDC) electrolyte. This work provides a self-assembled single-phase hexagonal cathode to accelerate the low-temperature hindrance of SOFC technology.

State of art of hydrogen utilization for building sector and set-up with preliminary experimental results of 1 kWel solid oxide fuel cell installed in a nearly zero energy house

The diffusion on large scale of the hydrogen-fueled technologies could be a strategy for boosting the expected decarbonisation of the civil sector. However, there are still a lot of unanswered questions about the real feasibility and the problems of the integration in a pre-existing building-plants system. Despite some conflicting opinions, the research about the application of the hydrogen system in the building sector must continue to make the technology more attractive and easily available at low cost. Therefore, first of all, the paper analyses advantages and issues through a broad overview. The main limits of the available studies regard both the approach and the technology integration. Indeed, there are few data about in-field performance analysis since the simulative/numerical investigations are usually based on in-lab prototypes. The most diffused systems referred to integrated energy solutions with proton exchange membrane fuel cell technology and in any case the integration in very low energy buildings such as the nearly zero energy (nZEB) ones is not discussed. Then basing on the discussed research gap, the paper focuses on the set-up of a new installation of micro-combined cooling, heating and power unit based on solid oxide fuel cell technology fueled by green hydrogen. The complexity in the design of the integration with other innovative plant configurations is discussed considering as real case study a nZEB in Mediterranean climate. Preliminarily experimental results show that the combination of fuel cell and photovoltaic system could bring to positive energy with surplus energy, during autumn season, of about 23.8 kWh. Moreover, it is also proposed the validation of a dynamic numerical model developed by means of TRNSYS (Transient System Simulation Tool) that will be used for further sensitivity analysis.

Internal dry reforming of methane in solid oxide fuel cells

In the context of global efforts to reduce greenhouse gas emissions and combat extreme global warming, the direct dry reforming of methane reaction in solid oxide fuel cells presents a promising avenue for clean energy production. This study delves into the influence of temperature, gas composition, and current density on the kinetics of dry methane reforming in solid oxide fuel cells. Power Law and Langmuir-Hinshelwood kinetic models were proposed to highlight the impact of operating conditions on dry methane reforming reactions. Results revealed that the feed gas composition strongly affects methane conversion, with higher methane contents resulting in lower conversions. Increasing the CH4/CO2 ratio increases reaction rates, and the effect decreases at a ratio of 1.25. The changes in methane concentration on dry methane reforming reaction rate are more significant than those for carbon dioxide. However, increasing carbon dioxide concentration enhances methane conversion. The exothermic nature of CO2 adsorption suggests that the adsorption process is thermodynamically favourable in dry reforming, and the elevated temperatures generally improve reaction rates and methane conversion by removing carbon deposits and providing the energy needed to break down the chemical bonds in methane which facilitating its transformation. A higher current density significantly enhances the CO2 adsorption equilibrium constant and further increases methane conversion, highlighting the positive role of electrochemical reactions on dry methane reforming. This study aims to fill the knowledge gap regarding the influence of electrochemical reactions on dry methane reforming behaviours in solid oxide fuel cells, offering critical insights for advancing anode design, thus contributing to the development of solid oxide fuel cell technologies to address global warming and reduce greenhouse gas emissions.

Performance improvement of fuel cell and photovoltaic system

This article considers and studies a hybrid energy storage system as a potential replacement for a utility grid. It also examines its organisational structure. The hybrid energy storage technology is used to ensure a constant supply of convenient grid electricity that is sufficient to handle changing power spikes. Batteries are used to stabilise the surges with measurable variation, whereas a massive capacitor is utilised to stabilise the surges with fast variation. In isolated areas where connecting to the main utility grid is impractical, standalone renewable generation may provide the advantage of a reduced operational cost as well as a reduction in protection fees. In order to encourage non-conventional power production in the overall renewable energy system, advancements in solid oxide fuel-cell technology and solar photovoltaic (PV) technology have also been made. Grid-coupled solar PV energy producing systems are being extensively used worldwide, and solar PV modules are increasingly being used in residential applications linked to the electrical grid.

Recent advancement of solid oxide fuel cells towards semiconductor membrane fuel cells

In the last few decades, there has been remarkable progress in the development of solid oxide fuel cells (SOFCs) based on both traditional solid electrolyte materials and novel semiconductor membranes. However, limited attention has been given to the transition of SOFCs from oxide ion-based electrolyte membranes to semiconductor membrane devices, considering the overall perspective of materials, technology, and scientific principles. Traditional knowledge strictly dictates that semiconductors should not be used as the membrane unless these materials possess negligible electronic conduction. This is because semiconductor membrane materials typically exhibit significantly higher electrical conductivity, surpassing the inherent ionic conductivity. Interestingly, by using semiconductors as the membrane, numerous novel materials have been demonstrated in the literature, which seems difficult to understand from traditional SOFC knowledge. Therefore, there is an emerging need to summarize and explore new understanding and knowledge of materials, technology, and science of SOFCs and Semiconductor Membrane Fuel Cells and their transition. In this review, we attempted to summarize the gap between the current state of SOFCs and the advancements in new materials, technologies, scientific principles, and mechanisms driving the development of such devices.

Toward solid-state Limetal-air batteries; an SOFC perspective of solid 3D architectures, heterogeneous interfaces, and oxygen exchange kinetics.

The full electrification of transportation will require batteries with both 3-5× higher energy densities and a lower cost than what is available in the market today. Energy densities of >1000 W h kg-1 will enable electrification of air transport and are among the very few technologies capable of achieving this energy density. Limetal-O2 or Limetal-air are theoretically able to achieve this energy density and are also capable of reducing the cost of batteries by replacing expensive supply chain constrained cathode materials with "free" air. However, the utilization of liquid electrolytes in the Limetal-O2/Limetal-air battery has presented many obstacles to the optimum performance of this battery including oxidation of the liquid electrolyte and the Limetal anode. In this paper a path towards the development of a Limetal-air battery using a cubic garnet Li7La3Zr2O12 (LLZ) solid-state ceramic electrolyte in a 3D architecture is described including initial cycling results of a Limetal-O2 battery using a recently developed mixed ionic and electronic (MIEC) LLZ in that 3D architecture. This 3D architecture with porous MIEC structures for the O2/air cathode is essentially the same as a solid oxide fuel cell (SOFC) indicating the importance of leveraging SOFC technology in the development of solid-state Limetal-O2/air batteries.

Study on the composite structure of cobalt-free oxides as cathodes for intermediate temperature solid oxide fuel cells (IT-SOFCs)

Summary: Solid Oxide Fuel Cells (SOFCs) represent a promising technology for efficient and clean energy conversion. This study focuses on the design and development of a novel cathode material for SOFCs, specifically exploring the use of a free-cobalt cathode within a composite structure. Investigating the structure of cobalt-free composites of Ba0.5Sr0.5FeO3-δ (BSF) and Ba0.5Sr0.5Fe0.8B0.2O3-δ (B=Cu, Zn) (BSFB) have been prepared and evaluated as cathodes for IT-SOFCs. The solid-state reaction was employed for generating and modifying the composite structure of the model system. The decomposition reaction and the formation of perovskite structure have been observed using thermal gravimetric analysis and X-ray diffraction. The study encompasses experimental procedures, data processing using GSAS software, and the application of the Rietveld method to achieve precise analysis results. Rietveld analysis outcomes offer intricate details about the crystal structure, encompassing crystal unit parameters, and scale factors. The solid-state reaction led to the reduction in the weight of the composite during the heating process. The decomposition reaction of oxides was generated between 650 to 950 oC. The average of total weight loss during the period treatment was achieved up to 18 % and the perovskite phase formed in the composite structure. A single-phase perovskite from a cubic structure with space group Pm-3m was demonstrated by all composite’s models. The lattice parameter and a unit cell volume were obtained from the model system of BSF, BSFC and BSFZ, respectively. This study explores the potential development of SOFCs technology with the hope of making a positive contribution to advancing clean and sustainable energy solutions in the future

Advancements in Perovskite-Based Cathode Materials for Solid Oxide Fuel Cells: A Comprehensive Review.

The high-temperature solid oxide fuel cells (SOFCs) are the most efficient and green conversion technology for electricity generation from hydrogen-based fuel as compared to conventional thermal power plants. Many efforts have been made to reduce the high operating temperature (>800 °C) to intermediate/low operating temperature (400 °C<T<800 °C) in SOFCs in order to extend their life span, thermal compatibility, cost-effectiveness, and ease of fabrication. However, the major challenges in developing cathode materials for low/intermediate temperature SOFCs include structural stability, catalytic activity for oxygen adsorption and reduction, and tolerance against contaminants such as chromium, boron, and sulfur. This research aims to provide an updated review of the perovskite-based state-of-the-art cathode materials LaSrMnO3 (LSM) and LaSrCOFeO3 (LSCF), as well as the recent trending Ruddlesden-Popper phase (RP) and double perovskite-structured materials SOFCs technology. Our review highlights various strategies such as surface modification, codoping, infiltration/impregnation, and composites with fluorite phases to address the challenges related to LSM/LSCF-based electrode materials and improve their electrocatalytic activity. Moreover, this study also offers insight into the electrochemical performance of the double perovskite oxides and Ruddlesden-Popper phase materials as cathodes for SOFCs.

Crossflow flat solid oxide fuel cell (SOFC) semi-empirical modeling and the multi-fuel property based on a commercial 700 W stack

Solid Oxide Fuel Cell (SOFC) technology has attracted vast attention for combined heat and power (CHP) application on low or zero carbon emissions because of its high efficiency and multi-fuel selectivity. Due to the high operation temperature, a commercial SOFC system requires a complex system thermal balance and stack self-heating ability which are dramatically influenced by the inlet temperature, reaction heat and thermal radiation of the stack. Multi-fuel selectivity is a further distinct advantage when considering the future variety of renewable fuel sources, such as ammonia (from animal farming), bio-methane (from agriculture), and the other hydrocarbons using carbon capture as an effective H2 carrier. However, the alternating between different fuel types may result in reduced power and the internal heat balance to change, which may further lead to the stack cooling down or over heated. An appropriate model with fast calculation processing capability is necessary to assess the internal changes before switching the fuel source and to inform further decision making to enable the control system to adapt to the change. In this paper, a cross-channel, flat SOFC semi-empirical model is proposed and validated by a commercial 700 W stack using real testing data to assess the accuracy of the simulation results. The SOFC model has multi-fuel ability which presents different properties and internal understanding for H2, NH3, and reformed CH4 through relevant charts (for feed, velocity, temperature, reaction rate, current, power, heat, efficiency). The power outputs for the different fuel sources, H2, NH3, and reformed CH4, are 721.0 W, 628.9 W and 679.7 W respectively when calculated at an air inlet temperature of 893 K. The modeling work was completed using Aspen Plus for SOFC system thermal balance simulations which determined the power output property for 813.3 W (H2), 744.5 W (direct NH3) and 740.7 W (reformed CH4) at the 2.0 times stoichiometric ratio of air feed, and CHP rate of 0.903 (H2), 0.787 (direct NH3) and 0.311 (reformed CH4). This work has the potential to contribute to the United Nation Sustainable Development Goal for Affordable and Clean Energy, Goal 7.

Thin film Si solar cell and solid oxide fuel cell technologies for a low cost, environmentally friendly and sustainable source of energy

Thin-film solar cell technology based on hydrogenated amorphous silicon has matured over the last two decades and is capable to deliver commercial modules with almost 10 % stabilized efficiency. Moreover attention on hydrogen fuel cells is increasing as the range of potential commercial applications expands, with more than 3800 fuel cell systems being installed and operated worldwide. These systems attain high theoretical efficiencies in the range of 43.7-70.4 %, with an additional 20% as heat recovery, and operating at carbon-free conditions between 50 °C and 900 °C. In this paper the status of thin-film silicon solar cell technology is reviewed by comparing it to other major solar cell technologies. A discussion is also made upon the benefits obtained from the few potential applications, as long-term potential actions for sustainable development, and the future of Solid Oxide Fuel Cells (SOFCs). Applications of thin-film silicon modules and SOFCs are presented. EPIA (European Photovoltaic Industry Association) estimates that half of the growth in the next two years will come from thin-film technology.

Evaluation of the environmental sustainability of SOFC-based cogeneration systems in commercial buildings

In order to achieve the European Union (EU)’s climate targets, efficient and sustainable solutions must be developed. In this context, the building sector has a key role to play in the transition to a decarbonized society. Cogeneration is considered an efficient solution that enables better use of fuel energy to supply buildings with heat and electricity. In particular, fuel cell-based cogeneration systems have shown promising performance, thus attracting considerable attention in recent years. The main goal of this study is to analyze the environmental impact of Solid Oxide Fuel Cell (SOFC) cogeneration systems, focusing on commercial buildings. The analysis was performed in the framework of the H2020 Comsos project, whose aim is to investigate the techno-economic and environmental feasibility of SOFC-based systems in non-residential buildings. An MILP-based optimization framework was developed to address the optimal design and operation of energy systems with the inclusion of SOFC-based cogeneration solutions. Electrical and thermal efficiency curves, derived from real SOFC operation, were used to improve the accuracy of the SOFC performance simulation. A sensitivity analysis on the carbon intensity of electricity was carried out to explore the role of the SOFC technology under different levels of electrical grid decarbonization. It was found that natural gas-fed SOFC systems become environmentally advantageous (in terms of CO2 emissions) when the carbon intensity of electricity is higher than ∼ 300 gCO2/kWh.

A novel multi-generation energy harvesting system integrating photovoltaic and solid oxide fuel cell technologies

This paper designs a new multi-generation system based on solar tower power supply, integrating a solid oxide fuel cell-gas turbine system, a supercritical recompressed carbon dioxide cycle, a Rankine cycle, an organic Rankine cycle, a compressed air energy storage system and a liquefied natural gas system. The aim is to overcome the intermittent and unstable nature of the solar power supply and ensure continuous power generation throughout the day, as well as improving the energy efficiency of the solar power system and minimising exhaust emissions from the integrated system. The system is modelled and evaluated in terms of energy, exergy, environment and economy. The results show the solar system energy efficiency of 10.09%, the total system energy efficiency of 19.28%, a round-trip efficiency of 58.66% and an exergetic round-trip efficiency of 52.06%, preventing the emission of 2090 tons of CO2 (a total of $50175 in environmental fines) per year. Finally, the proposed system was applied to a case study in the Xixiangtang district of Nanning, China, where the system, combined with real data, produced 24.8 MWh of electricity on the day with the highest direct of normal irradiance. In addition, the results of the economic analysis show the dynamic payback period is 6.9 years.