Theoretical Maximum Efficiency Research Articles

Designing new halide double perovskite materials Rb2AgGaX6 (X: Br, Cl) with direct band gaps and high power conversion efficiency

The development of lead-free inorganic halide perovskites has revolutionized photovoltaic and optoelectronic research in recent years. In this study, ab-initio methods have been implemented to predict the mechanical, optical, structural, and electronic properties of Rb2AgGaX6(X ​= ​Cl, Br). Through tolerance factor and third-order elastic constant analyses, we systematically probed the structural and mechanical strength characteristics of Rb2AgGaBr6 and Rb2AgGaCl6. These analyses provide both structural and mechanical stability. Additionally, thermodynamic stability tests were undertaken using formation energies. The calculated direct bandgaps by mBJ with spin-orbit-coupling are 2.53 ​eV and 1.28 ​eV for Rb2AgGaCl6 and Rb2AgGaBr6 respectively. The appropriate narrow electronic bandgaps provide visible-light absorption. Consequently, the optical properties revealed a high absorption coefficients (α(ω) ​≈ ​1.9 ​× ​105 ​cm−1 for Rb2AgGaBr6 and 2.1 ​× ​105 ​cm−1 for Rb2AgGaCl6), high conductivity and low reflectivity (R(ω) ​< ​10 %), which make the Rb2AgGaBr6 and Rb2AgGaCl6 attractive semiconductors for optoelectronic application. The theoretical maximum light conversion efficiency was calculated under AM1.5G solar illumination based on the variable thickness. The outcome is that bromine-based perovskite provides a superior efficiency of approximately 32.20 % and chlorine-based perovskite demonstrates an efficiency of 12.0 %. By virtue of extremely favorable bandgaps, low reflectivity and impressive efficiency, the eco-friendly halide perovskites appear to be auspicious clean renewable energy materials. Our results provide the scientific community with new insights and lead to the design of future solar cell devices.

Suitable Site Selection for Ocean Thermal Energy Conversion (OTEC) systems – A case study for Pakistan

In developing countries such as Pakistan, the issue of generating power is crucial. As conventional power sources (fossil fuels) are depleting at an alarming rate. An abundant amount of energy is generated by thermal power plants using fossil fuels as their primary energy resource for combustion. Hence extreme uses of fossil fuels are noticed, which is greatly responsible for damaging our environment. Oceans exists around 71% of the surface area of earth and it has enormous potential for electricity generation. This study focuses on site selection for harnessing ocean energy by utilizing Ocean Thermal Energy Conversion (OTEC) systems for coastal areas of Pakistan. In this study, four sites across the coastal region of Pakistan have been studied namely Karachi, Gwadar, Ormara and Pasni. Their theoretical maximum Carnot efficiencies have also been determined and Gwadar has been identified as the most suitable location for OTEC plant with the maximum theoretical efficiency of around 6.53%, 6.93% and 7.75% at the cold-water depths of 1000m, 1200m and 1500m, respectively.

The Betz limit and the corresponding thermodynamic limit

The Betz’s limit for the maximum efficiency of an ideal wind turbine imposes a maximum value of about 60% on the conversion of the kinetic energy of an airflow into work. In this paper, we analyze the reason for this value because, from a thermodynamic point of view, it can be 100%. The present work explains the reason for this difference, since it appears to be relevant from a didactic point of view. However, from a practical point of view, the Betz’s limit does not affect in any way the more useful and widespread expression for calculating the ideal maximum power of a wind turbine, which is at the origin of the referred limit. Complementarily, two approaches for the calculation of the theoretical maximum efficiency, in line with thermodynamics, are also presented in this work.

Development of a membrane-less microfluidic thermally regenerative ammonia-based battery towards small-scale low-grade thermal energy recovery

Developing low-cost and simple thermally regenerative ammonia-based batteries is a promising method to harvest low-grade waste heat. This paper proposes a membrane-less microfluidic thermally regenerative ammonia-based battery (M-TRAB) for harvesting low-grade waste heat. A liquid–liquid interface is developed by flowing co-laminar streams of anolyte and catholyte in a microchannel. It can replace the anion exchange membrane for separating reactants. A M-TRAB with a flow rate of 1500 μL min−1 obtains the maximum power density of 27 W m−2. The stable output voltage is generated with different flow rates, and the maximum theoretical thermal energy efficiency can reach 1.3% (the relative Carnot efficiency is 14.9%). And the influences of the microchannel length and NH3 concentration on the performance are investigated. Moreover, based on the lower density of anolyte than catholyte, a novel upward-anode structure forms a clearer interface, and almost non-existent ammonia-crossover occurs, especially in a tapered channel. And a maximum power density of 54.8 W m−2 is obtained. It indicates that the low-cost M-TRAB is a potential choice for assistant cooling in small systems.

Analysis of coupled heat & mass transfer during gas hydrate formation in bubble column reactors

Gas hydrates have promising applications in gas separation, carbon capture, desalination and gas storage. Although there exist several studies on modeling hydrate growth, analysis of the coupled role of heat and mass transfer on hydrate formation has been largely neglected. Presently, we develop a fundamentals-based simulations framework which accounts for mass transfer, heat transfer and various interfacial phenomena associated with gas hydrate formation in a bubble column reactor. We model CO2 separation from syngas via CO2 hydrate formation and validate against experiments from another study. This model is used to quantify the impact of various operating parameters (gas flow rate, bubble size, reactor pressure, inlet gas temperature, reactor geometry) on hydrate formation rate and gas-to-hydrate conversion factor. Results provide several insights related to the intricate transport phenomena that underlie hydrate formation. Firstly, we highlight the adverse impact of inadequate heat dissipation on hydrate formation rate and conversion factor. This is particularly important for high gas flow rates, wherein high hydrate formation rate triggers substantial temperature rise. Enhancing thermal conductivity of hydrate forming media can significantly enhance formation, with the conversion factor seen to double. Secondly, simulations show that bubbles < 100 μm diameter are essential to realize high growth rates. Thirdly, increasing reactor pressure can significantly improve the maximum theoretical separation efficiency for CO2 to > 90 %. Fourthly, precooling the inlet gas enhances hydrate formation rates by upto 5 %. Overall, this work outlines a novel approach to modeling hydrate formation and provides a tool for process optimization.

The influence of the water flow lens system on the operating characteristics of monocrystalline and amorphous Si‐solar cells for outdoor and indoor use: The photovoltaic improvement

AbstractThe operating characteristics of a commercial monocrystalline and amorphous Si‐solar cell for outdoor and indoor applications with and without the use of the water flow lens (WFL) system are explored and reported. The cells are tested in indoor conditions with halogen and tungsten lamps, and additionally, in outdoor sun radiation. Changes in the spectra, investigation of the influence of higher and lower lighting, and indirect cooling of the solar cell are possibilities in the application of the used WFL system. After achieving the highest level of development and improvement for the Si‐solar cell, as well as approaching theoretical maximum efficiency, it is obvious that efficiency gains can be made by better understanding additional light effects. Measurements made on monocrystalline Si‐solar cells revealed that in the “focal point position” where intensity increases (above standard testing conditions [STC]), independently of indoor or outdoor lighting, huge improvements in ISC and VOC were observed. It was found that the ratios of the short‐circuit current (ISC) and the input light energy (Pinput) are 5.2 and 24.8 for artificial light and 4.9 and 17.6 for outdoor light, without and with the use of the WFL system, respectively. The same trend after applying the WFL system was observed for the amorphous Si cell, except those oscillations were more pronounced at lower light intensities (far lower than STC), as expected. The ratios of ISC and Pinput are in the range of 5.1–5.3 and 10.5–26.5 without and with the use of the WFL system.

Variations in terms of CO2 capture and CH4 recovery during replacement processes in gas hydrate reservoirs, associated to the “memory effect”

The replacement of methane molecules, contained within natural hydrates reservoirs, with a theoretical equal number of carbon dioxide molecules, represents a promising opportunity for the near future. However, the maximum theoretical efficiency was proved to be approximately equal to 75% and, in the real applications, it is drastically lower. This article focused the attention on the possible reasons of such difference and found in the memory effect one of them. Firstly, the formation process of pure CH 4 and CO 2 hydrates was performed and thermodynamically characterized; then, the replacement process was realized on a system excluding memory and on a system including it. In the first situation, the theoretical efficiency was reached, while, in presence of memory effect, the results were drastically less effective, both in terms of methane recovery and in terms of carbon dioxide storage . When the system did not retain memory of previous formation processes, the quantity of CO 2 captured ranged from 73.97 to 75.05 vol% and the quantity of methane released was approximately equal to the one of CO 2 captured. Conversely, in presence of memory effect, the percentage of CO 2 captured dropped to 26 vol% and the quantity of methane release was still lower (24.97–26.03 vol%). • The influence of memory effect on the CO 2 /CH 4 replacement process was studied. • The memory effect was confirmed to be a kinetic promoter for hydrates formation. • The memory of previous CH 4 hydrates formation lowered the replacement efficiency. • Both the quantity of CH 4 released and CO 2 stored drastically decreased. • In absence of memory, the percentage of CO 2 storage reached the theoretical value.

Hydrogen Production and Storage: Analysing Integration of Photoelectrolysis, Electron Harvesting Lignocellulose, and Atmospheric Carbon Dioxide-Fixing Biosynthesis

Green hydrogen from photocatalytic water-splitting and photocatalytic lignocellulosic reforming is a significant proposition for renewable energy storage in global net-zero policies and strategies. Although photocatalytic water-splitting and photocatalytic lignocellulosic reforming have been investigated, their integration is novel. Furthermore, biosynthesis can store the evolved hydrogen and fix the atmospheric carbon dioxide in a biocathode chamber. The biocathode chamber is coupled to the combined photocatalytic water-splitting and lignocellulose oxidation in an anode chamber. This integrated system of anode and biocathode mimics a (bio)electrosynthesis system. A visible solar radiation-driven novel hybrid system comprising photocatalytic water-splitting, lignocellulose oxidation, and atmospheric CO2 fixation is, thus, investigated. It must be noted that there is no technology for reducing atmospheric CO2 concentration. Thus, our novel intensified technology enables renewable and sustainable hydrogen economy and direct CO2 capture from air to confront climate change impact. The photocatalytic anode considered is CdS nanocomposites that give a low absorption onset (200 nm), high absorbance range (200–800 nm), and narrow bandgap (1.58–2.4 V). The biocathode considered is Ralstonia eutropha H16 interfaced with photocatalytic lignocellulosic oxidation and a water-splitting anode. The biocathode undergoes autotrophic metabolism fixing atmospheric CO2 and hydrogen to poly(3-hydroxybutyrate) biosynthesis. As the hydrogen evolved can be readily stored, the electron–hole pair can be separated, increasing the hydrogen evolution efficiency. Although there are many experimental studies, this study for the first time sets the maximum theoretical efficiency target from mechanistic deductions of practical insights. Compared to physical/physicochemical absorption with solvent recovery to capture CO2, the photosynthetic CO2 capture efficiency is 51%. The maximum solar-to-hydrogen generation efficiency is 33%. Lignocelluloses participate in hydrogen evolution by (1–4)-glycosidic bond decomposition, releasing accessible sugar monomers or monosaccharides forming a Cd–O–R bond with the CdS/CdOx nanocomposite surface used as a photocatalyst/semiconductor, leading to CO32− in oxidised carboxylic acid products. Lignocellulose dosing as an oxidising agent can increase the extent of water-splitting. The mechanistic analyses affirm the criticality of lignocellulose oxidation in photocatalytic hydrogen evolution. The critical conditions for success are increasing the alcohol neutralising agent’s strength, increasing the selective (ligno)cellulose dosing, broadening the hybrid nanostructure of the photocatalyst/semiconductor, enhancing the visible-light range absorbance, and increasing the solar energy utilisation efficiency.

Understanding the Electronic Structure and Optical Properties of Vacancy-Ordered Double Perovskite A2BX6 for Optoelectronic Applications

Over the past few years, metal halide perovskite solar cells have made significant advances. Currently, the single-junction perovskite solar cells reach a conversion efficiency of 25.7%. Perovskite solar cells with a wide band gap can also be used as top absorber layers in multi-junction tandem solar cells. We examined the dynamical and thermal stability, electronic structure, and optical features of In2PtX6 (X = Cl, Br, and I) perovskites, utilizing first-principle calculations. The stability is predicted using phonon dispersion spectrum and ab initio molecular dynamics simulation and also through the convex hull approach. The lattice constants and the optimized volume show an increasing trend with changing halide ions. The band structures computed for In2PtCl6, In2PtBr6, and In2PtI6 indicate their semiconducting nature with band gap values of 2.06, 2.01, and 1.35 eV, respectively. Halogens p and Pt d orbitals, respectively, play a prominent role in the formation of states around valence band maximum and conduction band minimum. The compounds, namely, In2PtBr6 and In2PtI6, exhibit high dielectric constants and small carrier effective masses. Furthermore, we found that In2PtI6 reveals a maximum theoretical efficiency owing to its optimum band gap and high optical absorption and is comparable to MAPbI3 in the studied range. Our results suggest that In2PtX6 (X = Cl, Br, and I) are suitable materials for single-junction and top absorber layers in tandem solar cells.

A Transparent, High-Performance, and Stable Sb2 S3 Photoanode Enabled by Heterojunction Engineering with Conjugated Polycarbazole Frameworks for Unbiased Photoelectrochemical Overall Water Splitting Devices.

Developing low-cost, high-performance, and durable photoanodes is essential in solar-driven photoelectrochemical (PEC) energy conversion. Sb2 S3 is a low-bandgap (≈1.7eV) n-type semiconductor with a maximum theoretical solar conversion efficiency of ≈28% for PEC water splitting. However, bulk Sb2 S3 exhibits opaque characteristics and suffers from severe photocorrosion, and thus the use of Sb2 S3 as a photoanode material remains underexploited. This study describes the design and fabrication of a transparent Sb2 S3 -based photoanode by conformably depositing a thin layer of conjugated polycarbazole frameworks (CPF-TCzB) onto the Sb2 S3 film. This structural design creates a type-II heterojunction between the CPF-TCzB and the Sb2 S3 with a suitable band-edge energy offset, thereby, greatly enhancing the charge separation efficiency. The CPF-TCzB/Sb2 S3 hybrid photoanode exhibits a remarkable photocurrent density of 10.1mAcm-2 at 1.23V vs reversible hydrogen electrode. Moreover, the thin CPF-TCzB overlayer effectively inhibits photocorrosion of the Sb2 S3 and enables long-term operation for at least 100h with ≈10% loss in photocurrent density. Furthermore, a standalone unbiased PEC tandem device comprising a CPF-TCzB/Sb2 S3 photoanode and a back-illuminated Si photocathode can achieve a record solar-to-hydrogen conversion efficiency of 5.21%, representing the most efficient PEC water splitting device of its kind.

2D lead free Ruddlesden-Popper phase perovskites as efficient photovoltaic materials: A first-principles investigation

Though lead halide perovskites hold impressive optoelectronic properties, because of the bottleneck of lead toxicity, searching for the lead free perovskites is highly demanding for their commercial applications in the optoelectronic devices. Alongside of the lead free perovskites, two dimensional (2D) organic–inorganic hybrid halide perovskites (OIHHPs) are getting great attention as photovoltaic materials due to their air stability over the three dimensional(3D) counterpart and high performance. Herein, we have investigated recently synthesized lead free 2D Ruddlesden-Popper (RP) phase OIHHPs (X-PEA)2SnI4 (PEA=phenylethylammonium and X=H, para-F, meta-F, ortho-F) along with (PEA)2Sn1−xGexI4 where x = 0.5 and 1. Here studied all perovskites are direct band gap semiconductors with band gap in the solar energy region with high absorption coefficients. We have calculated the charge carrier effective masses along X–Γ–X and Y–Γ–Y and finally we have estimated maximum theoretical photoconversion efficiency (PCE) for all which reaches up to 25.58% making them suitable for their applications in high performance photovolatic devices.

Experimental beam combining stabilization using machine learning trained while phases drift.

An 8-beam, diffractive coherent beam combiner is phase controlled by a learning algorithm trained while optical phases drift, using a differential mapping technique. Combined output power is stable to 0.4% with 95% of theoretical maximum efficiency, limited by the diffractive element.

Relative straggle of sputtering parameters as a potential measure of power conversion efficiency of Perovskite materials

The growing demand for electricity necessitates the development of time-efficient computational methods in search of better solar energy-harvesting materials. One challenge has been ways to improve the power conversion efficiencies (PCEs) of potential harvesters.In this paper, an ion sputtering approach was used to study the problem of estimation of the power conversion efficiencies (PCEs) of perovskite solar device materials through their surface sputtering signatures. This rests on a hypothesis that the similarity between the phenomenon of photon excitation from light-sensitive absorbers, leading to electricity generation, and ejection of energetic particles from sputtered surfaces, could be exploited to estimate PCE. Hence, a Monte Carlo (MC) simulation of the sputtering of surfaces of perovskite materials with energetic ions was performed; and a number of quantities that could be used for the estimation of PCE were calculated. The results indicated that the relative straggle of surface sputtering parameters of the materials could be an effective measure of the theoretical maximum power conversion efficiencies of these materials. In particular, the relative straggle of the projected range of the ions in the respective materials was found to be close to reported experimental results of PCEs in the literature.

Design and Experimental Evaluation of a New RNA-FISH Probe to Detect and Identify Paenibacillus sp.

Paenibacillus, rod-saped gram-positive endospores forming aerobic or facultative anaerobic bacteria, colonize diverse ecosystems and are involved in the biodegradation of cultural heritage assets. Biodeteriogenic microorganisms can be easily detected/identified by ribonucleic acid- fluorescent in situ hybridization RNA-FISH with specific probes. In this work, probes designed in silico were analyzed to calculate hybridization efficiency and specificity by varying the formamide concentration in the hybridization. The Pab489 probe showed excellent in silico performance with high theoretical maximum efficiency hybridization (99.99%) and specificity and was selected for experimental assays with target Paenibacillus sp. and non-target biodeteriogenic microorganisms. Results assessed by epifluorescence microscopy and flow cytometry revealed that, regardless of the formamide concentration, it was possible to observe that the Pab489-Cy3 probe had a similar signal intensity to the EUB338-Cy3 probe (positive control), so the presence of formamide, a highly toxic and carcinogenic compound used to aid the hybridization process, is not necessary. The designed probe used in FISH assays allows specific in situ identification of Paenibacillus spp. in microbial communities in a culture-independent way. This approach can be employed for screening Paenibacillus spp., showing great potential for future application in biodeterioration of heritage assets, in the search for Paenibacillus strains that produce compounds with biotechnological or medical potential.

Comparison between spectrum-split conversion and thermophotovoltaic for solar energy utilization: Thermodynamic limitation and parametric analysis

The mismatch between solar radiation spectrum and photovoltaic cells is the main obstacle on photovoltaic efficiency. Solar spectrum-split conversion (SSSC) and solar thermophotovoltaic (STPV) are two important technologies to solve this problem. In this study, the basic characteristics of the two technologies are considered and compared from the perspectives of thermodynamic evaluation and parameter analysis. Based on the radiative thermodynamics, a theoretical model is established to analyze the thermodynamic limitation of the solar spectrum-split photo-thermal cascade conversion, which is in the range of 84.96%–93.10% and higher than that of STPV (84.96%). Furthermore, a parameter model is established for the three-band solar spectrum-split photovoltaic-heat engine combined system. Parameter optimization analysis indicates that the theoretical efficiency of the three-band SSSC system can reach 64%, which is higher than the two-band spectrum-split by 5–20 percent points and is also higher than the theoretical maximum efficiency of STPV by approximately 25 percent points. The study points out that the high-temperature emission loss of STPV absorber for concentrating solar energy is as high as 70%, which is the loss of high-quality energy and directly reduces the working capability of solar energy. Future development of STPV should pay more attention to the selective absorbers. The study provides guidance for the integrated utilization of solar energy.

Optimization of the Efficiency of a Michell-Banki Turbine through the Variation of its Geometrical Parameters using a PSO Algorithm

Small-scale hydropower generation can satisfy the needs of communities located near natural sources of flowing water. The operating conditions of a Michell–Banki Turbine (MBT) are relatively easier to meet than those of other types of turbine, making it useful in places where other devices are not suitable. Moreover, MBT efficiency is almost invariable with respect to flow rate conditions. Nevertheless, such efficiency commonly ranges between 70% and 85%, which is lower than that of other water turbines like Turgo, Pelton, or Francis turbine. The objective of this work is to determine the maximum theoretical efficiency of an MBT and its associated geometrical parameters by implementing Particle Swarm Optimization. The results show a higher effectiveness of the mathematical formulation compared with other cases from literature and show the performance of the optimization method proposed in this study in terms of solution and processing time. Finally, a maximum MBT efficiency of 93.3% was achieved.

Optimization of Impedance-Source Galvanically Isolated DC–DC Converters With Reduced Number of Switches

In this study, a new type of Z-source converter comprising galvanic isolation transformers is introduced based on classical non-isolated Z-source converters, which are promising devices for renewable applications. Compared to the typology of conventional converters with isolation transformers, the proposed converter topology has a simpler structure with fewer power switches and lower costs. Considering the lower number of switching devices required in the proposed typology, these efficiency and reliability of the presented converters are higher than those of the conventional ones. As only one switch is used in the developed structure, voltage stresses on the Z-source converter decreases in each period, which maintains voltage stress low and steady across the switch. Another desirable feature of the proposed topology is reduced converter size and volume with a maximum theoretical and practical efficiency of 97 to 94.05%, respectively. Moreover, these converters need low input voltage and provide the required amount of output voltage in small duty cycles. The theoretical and operational analysis of the designed converter and its comparison with other counterpart converters (e.g., isolated Z-source converters) is presented. The simulation and experimental results confirm the applicability of the proposed system.

Geometrical parameter optimization of planner square-shaped printed spiral coil for efficient wireless power transfer system to biomedical implant application

In this paper, the wireless recharging of pacemaker's battery for biomedical implant is considered. Planner square-shaped printed spiral coils (PSCs) are selected as primary (Tx) and secondary (Rx) coil for wireless power transfer (WPT) system. FEM based simulation method is used to optimize the geometrical parameters of square-shaped PSCs. The receiving coil is embedded inside the biomedical implant. The coil track width (w), pitch(s), thickness (t), number of turns(N1,N2) and outer diameter (Dout) of square-shape PCS's are the key parameters for higher coupling coefficient and quality factors. Using magnetic resonance coupling (MRC) based on Series-Parallel (SP) topology; experiments are carried out in an analytical, simulation, and physical environment for four operating frequencies: 300 kHz, 800 kHz, 6.78 MHz, and 13.56 MHz. Efficiency obtained by analytical and simulation method is higher with frequency. The optimum frequency for recharging the pacemaker battery is 6.78 MHz, which provides an efficiency of 85.51% at 100Ω load and is very close to the maximum theoretical efficiency. Voltage gain obtained by physical method is in close approximation with analytical and simulation methods.

Efficient Triplet-Triplet Annihilation Upconversion in Solution and Hydrogel Enabled by an S-T Absorption Os(II) Complex Dyad with an Elongated Triplet Lifetime.

A new Os(II) complex dyad featuring direct singlet-to-triplet (S-T) absorption and intramolecular triplet energy transfer (ITET) with lifetime up to 7.0 μs was designed to enhance triplet energy transfer efficiency during triplet-triplet annihilation upconversion (TTA-UC). By pairing with 9,10-bis(phenylethynyl)anthracene (BPEA) as a triplet acceptor, intense upconverted green emission in deaerated solution was observed with unprecedented TTA-UC emission efficiency up to 26.3% (with a theoretical maximum efficiency of 100%) under photoexcitation in the first biological transparency window (650-900 nm). Meanwhile, a 7.1% TTA-UC emission efficiency was acquired in an air-saturated hydrogel containing the photosensitizer and a newly designed hydrophilic BPEA derivative. This ITET mechanism would inspire further development of a highly efficient TTA-UC system for biological fields and renewable energy production.

Analysis on thermodynamic and economic performances of supercritical carbon dioxide Brayton cycle with the dynamic component models and constraint conditions

Turbomachinery and heat exchanger are key components of the supercritical carbon dioxide (CO2) Brayton cycle system. It is of great necessity to investigate realistic cycle performance coupled with components characteristics. This paper analyzes the efficiency and economy of supercritical CO2 Brayton cycle based on the dynamic component models and constraint conditions. The parametric limits are compressor inlet temperature range from 305 K to 310 K, inlet pressure range from 7.4 MPa to 8.3 MPa, and maximum cycle pressure range from 15 MPa to 30 MPa. The results reveal that the achievable efficiency of a simple cycle is 0.13–0.62% points lower than theoretical maximum efficiency after considering constraint conditions. Meanwhile, the levelized cost of electricity (LCOE) under constraint conditions is 0.00038–0.00085$/(kW·h) higher than the theoretical minimum LCOE. For a recompression cycle, constraint conditions have a more significant impact. The achievable efficiency of the cycle is 0.81–1.21% points lower than the maximum efficiency because of the constraints, and the available LCOE under constraint conditions is 0.0012–0.0018$/(kW·h) higher than the theoretical minimum LCOE.