Attainable Efficiency Research Articles

Impact of Temperature and Optical Error on the Combined Optical and Thermal Efficiency of Solar Tower Systems for Industrial Process Heat

Concentrating solar thermal (CST) power towers can provide high flux concentrations at commercial scale. As a result, CST towers exhibit potential for high-temperature solar industrial process heat (SIPH) applications. However, at higher operating temperatures, thermal radiation losses can be significant. This study explores the trade-off between thermal and optical losses for SIPH applications using a collection of three case studies at operating temperatures that range from 900-1,550 °C. We assume blackbody radiation to represent the thermal losses at the receiver and we use ray tracing to estimate the optical losses. The results show the impact of process temperature on the maximum attainable system efficiency, as well as the higher flux concentration requirements as the temperature increases.

Generation of THz radiation through molecular modulation in hydrogen-filled hybrid anti-resonant fibers.

We study the generation of narrowband terahertz (THz) pulses by stimulated Raman scattering and molecular modulation in hydrogen-filled hybrid hollow-core fibers. Using a judicious combination of materials and transverse structures, this waveguide design enables simultaneous confinement of optical and THz signals with reasonably low attenuation, as well as high nonlinear overlap. The THz pulses are then generated as the second Stokes band of a ns-long near-infrared pump pulse, aided by Raman coherence waves excited in the gaseous core by the beat-note created by the pump and its first Stokes band. Optimization of the fiber characteristics facilitates phase matching between the corresponding transitions and coherence waves while avoiding coherent gain suppression, resulting in potential optical-to-THz conversion efficiencies up to 60%, as confirmed by rigorous numerical modelling under ideal zero-loss conditions. When the current optical material constraints are considered, however, the attainable efficiencies relax to 0.2%, a still competitive value compared to other systems. The approach is in principle power and energy scalable, as well as tunable in the 1-10 THz range without any spectral gaps, thereby opening new pathways to the development of fiber-based THz sources complementary to other mature technologies such as quantum cascade lasers.

Performance analytics of adaptive subcarrier intensity modulated free-space optical communications over general Málaga turbulence links

In this paper, we study the performance analysis of free-space optical (FSO) system employing a constant-power variable-rate adaptive subcarrier intensity modulation (SIM) and utilizing phase-shift keying (PSK) over the Málaga atmospheric turbulence with pointing errors. According to a target bit-error rate (BER) and the instantaneous signal-to-noise ratio (SNR), the adaptive strategy adopts the subcarrier PSK modulation order. More precisely, we develop new analytical expressions for the average BER, the upper bound on ergodic channel capacity for non-adaptive modulation, and the attainable spectral efficiency (SE) of an adaptive SIM-FSO communication system. According to the simulation results, it is possible to achieve an increase in SE under weak-to-strong turbulence conditions without the need to increase the average optical power transmitted or compromise the BER requirements.

Multi-criteria assessment and optimization of a biomass-based cascade heat integration toward a novel multigeneration process: Application of a MOPSO method

In this study, a novel biomass-driven cascade heat integration scheme is devised, encompassing combined cooling, heating, and power generation, with a unique focus on the production of a secondary product (freshwater). The process commences with the establishment of a biomass digester, yielding biogas fuel to kickstart the integrated system. Subsequently, the utilization of a gas turbine cycle is introduced, and its waste heat is efficiently harnessed through a supercritical carbon dioxide process, a double-effect refrigeration cycle, and a heating terminal. Additionally, a modified organic Rankine cycle is incorporated to recover heat from the supercritical carbon dioxide process, while reverse osmosis desalination forms an integral part of the equipment lineup. The entire system is rigorously evaluated from both thermodynamic and economic standpoints, undergoing optimization across five distinct scenarios. A multi-objective particle swarm optimization approach, featuring two decision-making algorithms, is deployed in this optimization process. The primary objective is exergetic efficiency, while the secondary objectives encompass net output power, cooling, heating, sum unit cost of products, and net present value, each considered individually. The results of the study reveal that the highest attainable optimal exergy efficiency stands at 38.54 % when the secondary objective is net output power. Furthermore, the optimal values for the secondary objectives are determined to be 41112.59 kW, 1383.75 kW, 28413.97 kW, 18.72 $/GJ, and 75.17 M$, respectively. These findings underscore the potential of the proposed biomass-driven cascade heat integration system in achieving efficient and sustainable energy generation while simultaneously producing valuable secondary products.

Multi-Objective Optimization in Solar and Wireless Energy Harvesting the IoT Relay Communication System

In this article, a solar and wireless energy harvesting (SWEH) Internet of Things network is presented. To address energy efficiency problems, we consider an amplify-and-forward relay node that harvests solar and wireless energy using the power splitting protocol to accomplish SWIPT. For the communication model under consideration, we derive the mathematical expressions for throughput and energy efficiency. We investigate the impact of both power transmitted by the source and power-splitting factor on the system’s achievable energy efficiency and the energy harvested. To maximize the contradictory objectives of energy efficiency and energy harvested simultaneously, we propose to use the Pareto-based multi-objective ant lion optimization algorithm (MOALO) and jointly optimize the transmitted power and power-splitting factor. In-depth simulation is used to determine the Pareto optimal values for transmitted power and power-splitting factor and to assess how the proposed algorithm performs in comparison to leading-edge algorithms such as NSGA-II, MOPSO, MOWOA, and MOMVO. The results unambiguously show that the suggested MOALO offers the best Pareto front within a reasonable amount of time. Finally, the results corroborate that the proposed SWEH system outperforms in terms of harvested energy and attainable energy efficiency.

Potentials of InxGa1-xN photovoltaic tandems

During the past few years a great variety of multi-junction solar cells has been developed with the aim of a further increase in efficiency beyond the limits of single junction devices. In this work, the solar power conversion efficiency of InxGa1-xN based tandem solar cells was investigated. With this intention, one simulation of the spectral response and the current-voltage characteristic was carried out using a simulation program designed under ‘Visual Basic 5’ language for this reason. Our cal culation indicates that the attainable efficiency can be enhanced up to 34 % and 37% for tandems with double and triple junctions respectively, obtained under 1-sun AM1.5 illumination and at ambient temperature, using realistic material parameters. A comparison has been made of our results with those of other models.

(Invited) Recent Advances in Thermally Regenerative Batteries: A New Approach for Generating Electrical Power from Low-Grade Heat

Thermally regenerative flow batteries (TRBs) seek to tap into the unused terawatt-hours of low-grade heat that are currently being expelled from industrial plants and stationary power sources each year. Unlike typical flow batteries, TRBs can be recharged using thermal energy, therefore increasing grid efficiency by using an energy stream that is already widely available. This unique feature is accomplished through a thermally recoverable energy carrier that, when added or removed from an electrolyte, dramatically alters the standard electrode potential of an electrode reaction. To date, most TRBs use ammonia as the energy carrier, which lowers the standard electrode potential of their anode reaction by complexing with transition metal ions such as copper, silver, or zinc. Despite the early successes of TRBs relative to other emerging electrochemical technologies trying to harness low-grade thermal energy sources, they still lacked the energy efficiency and power densities needed to be economically viable. The first iterations of TRBs had peak power densities up to 3 mW cm-2 with competitive theoretical energy efficiencies (up to 1 %), but they suffered from extreme coulombic efficiency issues that limited realizable energy production values. Herein, we will discuss recent changes that have greatly improved the performance possible from these systems and discuss persistent challenges that remain to be solved. Coulombic inefficiencies were resolved by replacing unstable deposition-based reactions with all-aqueous alternatives that provided larger cell potentials and coulombic efficiencies for single metal and bimetallic-TRB systems. Electrolyte composition, operating temperature, and membrane transport all strongly influenced energy efficiency and power density limits from these new electrolyte chemistries. Peak power densities up to 100 mW cm-2 and theoretical energy efficiencies up to 12 % were identified through a preliminary survey of possible design choices. However, tradeoffs between attainable power density and energy efficiency limited cell performance values to a fraction of these values. Future work to better control diffusive transport without conductivity losses will be crucial for approaching theoretical battery performance limits.

A new look at imines and their mixture with PC71BM for organic, flexible photovoltaics

Due to its high electron affinity and electron mobility in a wide absorption range of the visible solar spectrum, [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) is often used as an efficient acceptor in organic photovoltaics. In turn, imines are additives to the active layer of organic solar cells, mainly due to the free electron pair of the imine nitrogen atom and the presence of various chemical groups affecting the polarity and conformations of molecules. However, the attainable efficiency is not as high as expected. Therefore, we have systematically investigated two imines and their mixtures with PC71BM by spectroscopic (the high pressure UV–Vis and frequency domain dielectric), thermoelectric, and mechanical methods for organic, flexible photovoltaics. Both the imines, (N,NʹE,N,NʹE)-N,Nʹ-([2,2ʹ:5ʹ,2ʺ-terthiophene]-5,5ʺ-diylbis(methanylylidene))bis(benzo[d]thiazol-2-imine) (SC3) and (6E)-N-((5-(5-(5-((E)-(4-(4-(4-fluorophenyl)thiazol-2-yl)phenylimino)methyl)thiophen-2-yl)thiophen-2-yl)thiophen-2-yl)methylene)-4-(4-(4-fluorophenyl)thiazol-2-yl)benzenamine (SC13), have the same core composed of three thiophene rings but different terminal chains of the molecules. In the imine SC3, the imine bond is followed by benzothiazole rings on both sides of the core, while in SC13, a thiazole ring separates two benzene rings, the terminal one F-substituted. The difference in molecular structure affects the electric properties of the neat imine and its mixed layers. An addition of PC71BM to the imines improves their electric conductivity. The mechanical studies focused on the stress at break and elongation showed superior behaviour compared to fullerene derivative. High pressure systematically reduces the band gap energy, Eg, from 1.68 eV at 0.16 GPa to 1.51 eV at 2.69 GPa for PC71BM, from 1.77 eV at 0.1 MPa to 1.53 eV at 4.15 GPa for SC3, and from 1.99 eV at 0.11 GPa to 1.8 eV at 3.10 GPa for SC13, as determined by the UV–Vis absorbance measurements in a diamond-anvil cell. These Eg reductions reflect the compressed intermolecular interactions that can be used to monitor the structural stability of these compounds. Based on the dielectric studies it was found that the relaxation processes registered for both imines are probably the grain boundary relaxation. Two processes also appear in the systems with PC71BM, but none of them is the one characteristic of imines. The high-frequency process has a dipole character while the low-frequency one is probably the grain boundary relaxation of these systems. The mechanism of quasi-DC conduction in various temperature ranges in the studied systems was also determined.

Numerical Simulation of Nitrogen-Doped Titanium Dioxide as an Inorganic Hole Transport Layer in Mixed Halide Perovskite Structures Using SCAPS 1-D

Perovskite solar cells (PSCs) stand out as superior third-generation (III-gen) thin-film energy harvesting structures with high efficiency, optical properties and light transmission ability. However, the need to develop cost-effective, stable and sustainable PSCs is allied to the influence of the absorber layer and charge selective transport layers when achieving semi-transparent (ST) structures. Using SCAPS simulation software that can envisage the conceptuality in devising ST PSCs, this work explores and reports the electrical performance of different methylammonium (MA)-based perovskite structures (FTO/TiO2/PCBM/SnO2/MAPbI3/TiO2:N/PTAA/Spiro-OMeTAD/PEDOT: PSS/Ag). The influence of absorber thickness and defect density is analyzed with optimal parameters. This research reports a novel idea that replaces the polymeric hole transport layer (HTL), such as Spiro-OMeTAD, PEDOT: PSS and PTAA with an air-stable inorganic metal oxide, viz., nitrogen-doped titanium dioxide (TiO2:N). The simulation results depict an attainable power conversion efficiency of 9.92%, 10.11% and 11.54% for the proposed structures with the novel HTL that are on par with polymeric HTLs. Furthermore, the maximum allowable absorber thickness was 600 nm with a threshold defect density of 1 × 1015 cm−3. The optimized electrical parameters can be implemented to develop thin-film light transmission perovskite cells with rational power conversion efficiencies.

Effect of Actual Recuperators’ Effectiveness on the Attainable Efficiency of Supercritical CO2 Brayton Cycles for Solar Thermal Power Plants

One of the most promising concentrated solar power technologies is the central receiver tower power station with heliostat field, which has attracted renewed research interest in the current decade. The introduction of the sCO2 recompression Brayton cycles in the near future installations instead of the Rankine cycle is very probable, due to the prospects of a significant efficiency improvement, process equipment size and capital cost reduction. In this study, energy and exergy analysis of a recompression Brayton cycle configuration for a central receiver power station are performed. Special emphasis is given to the computation of actual performance for the High-Temperature Recuperator and the Low-Temperature Recuperator. The results define realistic thermal and exergetic efficiency limits for the specific cycle configurations applied on a central receiver solar power plant with variable turbine entry temperature. Thermal efficiency, predicted with the improved accuracy of heat exchanger computations, does not exceed the 50% target. Overall, a realizable total power plant efficiency of 37% at 900 K turbine entry temperature is predicted, which is a significant improvement on the current state-of-the-art with steam Rankine cycles.

Optimal Achievable Transmission Capacity Scheme for Full-Duplex Multihop Wireless Networks.

Full-duplex (FD) communication has been attractive as the breakthrough technology for improving attainable spectral efficiency since the 5G mobile communication system. Previous research focused on self-interference cancellation and medium access control (MAC) protocol to realize the FD system in wireless networks. This paper proposes an optimal achievable transmission capacity (OATC) scheme for capacity optimization in the FD multihop wireless networks. In this paper, the proposed OATC scheme considers the temporal reuse for spectral efficiency and the spatial reuse with transmit power control scheme for interference mitigation and capacity optimization. OATC scheme controls the transmit power to mitigate interference and optimizes the transmission capacity, which leads to the optimal achievable network capacity. We conduct the performance evaluation through numerical simulations and compare it with the existing FD MAC protocols. The numerical simulations reveal that considering only the concurrent transmissions in the FD system does not guarantee optimal transmission capacity. Moreover, the hybrid mechanism, including the sequential transmissions, is also crucial because of the interference problem. Besides, numerical simulation validates that the proposed OATC scheme accomplishes the optimal achievable network capacity with lower interference power and higher achievable throughput than the existing MAC protocols.

(Invited) Atmospheric Plasmas Synthesized Nanocrystals with Quantum Confinement and Quantum Hybrids in Photovoltaics

Nanocrystals share lot of advantages of organics namely scalable and controlled synthesis, an ability to be processed in solution while additionally retaining the broadband absorption and superior transport properties of traditional photovoltaic semiconductors. Nanocrystal solar cells have the potential to considerably increase the maximum attainable thermodynamic conversion efficiency (> 50%). Nanocrystal solution-processed can be used in solar cell structure not only as an absorber but also as electron and hole transport layer where the HOMO and LUMO levels can be efficiently controlled by size and/or plasma induced surface engineering directly in colloidal solution. Solution-processed and surface engineered nanocrystals with quantum confinement can be then further used to fabricate new class of quantum hybrids when blended for instance with polymers or perovskites and serves as absorbing and/or e-h transporting material. In this presentation, we overview the atmospheric plasma-based approaches to synthesis and surface engineering of nanocrystals with quantum confinement. We will compare surface engineering by fs laser processing in liquid solutions and synthesis of nanocrystals with strong quantum confinement by atmospheric plasmas. Moreover, to understand the thermal stability of nanocrystals observed experimentally, we calculate the cohesive and the formation energies of nanocrystals by means of first-principle calculations. Finally, we overview our recent progress in integration of surface engineered nanocrystal as a quantum hybrids incorporated within perovskites solar cells.

Reshaping How We Think about Soil Security

The soil security framework has been conceptualized and views soil as a resource that needs to be secured to avoid or minimize adverse environmental/anthropogenic impacts and undesirable consequences for people. Our critical literature review suggests that measurements, estimations, simulations, or digital mapping of soil properties fall short in assessing soil security and health. Instead, soil security that considers soil ecosystem functionality based on regionalized and optimized relationships between targeted functions and site-specific soil environmental conditions allows for the discernment of actual and attainable efficiency levels for observation sites. We discuss the pros and cons that undergird the paradigm shift toward a pedo-econometric modeling approach. Such a multiperspectival approach to soil security allows for simultaneous interpretations from economic, pedogenic, agronomic, environmental, biotic/habitat, and other perspectives. This approach is demonstrated by modeling total nutrient efficiencies in complex multi-use soilscapes with diverging soil environmental interests and concerns.

FD-MCST design and analysis for multihop wireless networks

Full-duplex (FD) wireless communication improves the attainable spectral efficiency of the wireless network with the simultaneous transmission and reception over the same frequency channel at a single timeslot. However, the effect of self-interference (SI) and inter-user interference (IUI) become crucial to take into consideration compared to the current half-duplex system. Many researches have been studied to suppress the SI and IUI, to design the medium access control (MAC) protocol, and to propose resource management techniques for realizing the FD system and truly achieving the double transmission capacity in the network. In this paper, we propose a novel FD MAC protocol with a mixture of concurrent and sequential transmission scheme, namely FD-MCST, for maximizing the transmission capacity in multihop wireless networks. Through FD-MCST, the transmitting node can cooperatively share the transmission capacity status for maximizing the network capacity. As a result, numerical simulations reveal that the proposed FD-MCST can accomplish a higher achievable network capacity of up to 1.7 times and nearly twice the achievable throughput with a reasonable amount of achievable transmission overhead about 7.7%, compared to the existing FD MAC protocols.

CuSbS2 thin films by heat treatment of thermally evaporated Sb2S3/CuS stack: Effect of [Cu]/[Sb] ratio on the physical properties of the films

We report the experimental development and theoretical evaluation of single-phase CuSbS2 thin films with the purpose of studying a material with potential applications in photovoltaics. Optimal control of [Cu]/[Sb] ratio in the evaporated Sb2S3/CuS stack allowed to tune the stoichiometry, electron affinity, and bandgap of the processed CuSbS2 thin films. The CuSbS2 film developed with [Cu]/[Sb] ratio 0.96 is phase-pure with a band gap of 1.55 eV and exhibited higher photosensitivity. The film is p-type with carrier concentration ∼8.5 x 1017 cm−3. Device simulations were performed to estimate the attainable efficiency with an ideal absorber film and compared with the experimentally determined material parameters of the film developed in this work. Our device model assumes carrier recombination via defects at both CuSbS2/CdS interface and in the CuSbS2 bulk, suggesting that the experimentally reported low values of Voc can be attributed to two factors: (i) the defects at the absorber/buffer interface, and (ii) doping concentration in the CuSbS2 layer. In particular, the concentration of shallow acceptors (NA) in CuSbS2 bulk has a crucial effect on the power conversion efficiency (PCE). The results of this study offers new insight into pathways for increasing the Voc and PCE of CuSbS2 based devices.

Smart pooling: AI-powered COVID-19 informative group testing

Massive molecular testing for COVID-19 has been pointed out as fundamental to moderate the spread of the pandemic. Pooling methods can enhance testing efficiency, but they are viable only at low incidences of the disease. We propose Smart Pooling, a machine learning method that uses clinical and sociodemographic data from patients to increase the efficiency of informed Dorfman testing for COVID-19 by arranging samples into all-negative pools. To do this, we ran an automated method to train numerous machine learning models on a retrospective dataset from more than 8000 patients tested for SARS-CoV-2 from April to July 2020 in Bogotá, Colombia. We estimated the efficiency gains of using the predictor to support Dorfman testing by simulating the outcome of tests. We also computed the attainable efficiency gains of non-adaptive pooling schemes mathematically. Moreover, we measured the false-negative error rates in detecting the ORF1ab and N genes of the virus in RT-qPCR dilutions. Finally, we presented the efficiency gains of using our proposed pooling scheme on proof-of-concept pooled tests. We believe Smart Pooling will be efficient for optimizing massive testing of SARS-CoV-2.

Evaluation of probabilistic constellation shaping performance in Flex Grid over multicore fiber dynamic optical backbone networks [Invited

In this paper, we present a worst-case methodology for estimating the attainable spectral efficiency over end-to-end paths across a Flex Grid over multicore fiber (MCF) optical network. This methodology accounts for physical link noise, as well as for the signal-to-noise ratio in the Add module ( S N R T X ) of spatial-division-multiplexing-enabled reconfigurable optical add and drop multiplexers (SDM-ROADMs), introducing a dominant noise contribution over that of their Bypass and Drop modules. The proposed methodology is subsequently used to quantify the benefits that probabilistic constellation shaping (PCS) can bring to Flex-Grid/MCF dynamic optical backbone networks, compared to using traditional polarization-multiplexed modulation formats. In a first step, insight is provided into the spectral efficiency attainable along the precomputed end-to-end paths in two reference backbone networks, either using PCS or traditional modulation formats. Moreover, in each one of these networks, two S N R T X values are identified: the S N R T X yielding the maximum average paths’ spectral efficiency, as well as an S N R T X that, although slightly degrading the average paths’ spectral efficiency (by 10%), would yet enable a cost-effective SDM-ROADM Add module implementation. Extensive simulations are conducted to analyze PCS offered load gains under 1% bandwidth blocking probability. Furthermore, the study lastly focuses on finding out whether lower fragmentation levels in Flex-Grid/MCF dynamic optical backbone networks can push PCS benefits even further.

Towards machine learning aided real-time range imaging in proton therapy

Compton imaging represents a promising technique for range verification in proton therapy treatments. In this work, we report on the advantageous aspects of the i-TED detector for proton-range monitoring, based on the results of the first Monte Carlo study of its applicability to this field. i-TED is an array of Compton cameras, that have been specifically designed for neutron-capture nuclear physics experiments, which are characterized by gamma -ray energies spanning up to 5–6 MeV, rather low gamma -ray emission yields and very intense neutron induced gamma -ray backgrounds. Our developments to cope with these three aspects are concomitant with those required in the field of hadron therapy, especially in terms of high efficiency for real-time monitoring, low sensitivity to neutron backgrounds and reliable performance at the high gamma -ray energies. We find that signal-to-background ratios can be appreciably improved with i-TED thanks to its light-weight design and the low neutron-capture cross sections of its LaCl_{3} crystals, when compared to other similar systems based on LYSO, CdZnTe or LaBr_{3}. Its high time-resolution (CRT sim 500 ps) represents an additional advantage for background suppression when operated in pulsed HT mode. Each i-TED Compton module features two detection planes of very large LaCl_{3} monolithic crystals, thereby achieving a high efficiency in coincidence of 0.2% for a point-like 1 MeV gamma -ray source at 5 cm distance. This leads to sufficient statistics for reliable image reconstruction with an array of four i-TED detectors assuming clinical intensities of 10^{8} protons per treatment point. The use of a two-plane design instead of three-planes has been preferred owing to the higher attainable efficiency for double time-coincidences than for threefold events. The loss of full-energy events for high energy gamma -rays is compensated by means of machine-learning based algorithms, which allow one to enhance the signal-to-total ratio up to a factor of 2.

Absorption and scattering in perfect thermal radiation absorber-emitter metasurfaces.

Detailed spectral analysis of radiation absorption and scattering behaviors of metasurfaces was carried out via finite-difference time-domain (FDTD) photonic simulations. It revealed that, for typical metal-insulator-metal (MIM) nanodisc metasurfaces, absorbance and scattering cross-sections exhibit a ratio of σabs/σsca = 1 at the absorption peak spectral position. This relationship was likewise found to limit the attainable photo-thermal conversion efficiency in experimental and application contexts. By increasing the absorption due to optical materials, such as Cr metal nano-films typically used as an adhesion layer, it is possible to control the total absorption efficiency η = σabs/σsca and to make it the dominant extinction mechanism. This guided the design of MIM metasurfaces tailored for near-perfect-absorption and emission of thermal radiation. We present the fabrication as well as the numerical and experimental spectral characterisation of such optical surfaces.

Simultaneous wireless information and power transfer with fixed and adaptive modulation

Activating Wireless Power Transfer (WPT) in Radio-Frequency (RF) to provide on-demand energy supply to widely deployed Internet of Everything devices is a key to the next-generation energy self-sustainable 6G network. However, Simultaneous Wireless Information and Power Transfer (SWIPT) in the same RF bands is challenging. The majority of previous studies compared SWIPT performance to Gaussian signaling with an infinite alphabet, which is impossible to implement in any realistic communication system. In contrast, we study the SWIPT system in a well-known Nakagami-m wireless fading channel using practical modulation techniques with finite alphabet. The attainable rate-energy-reliability tradeoff and the corresponding rationale are revealed for fixed modulation schemes. Furthermore, an adaptive modulation-based transceiver is provided for further expanding the attainable rate-energy-reliability region based on various SWIPT performances of different modulation schemes. The modulation switching thresholds and transmit power allocation at the SWIPT transmitter and the power splitting ratios at the SWIPT receiver are jointly optimized to maximize the attainable spectrum efficiency of wireless information transfer while satisfying the WPT requirement and the instantaneous and average BER constraints. Numerical results demonstrate the SWIPT performance of various fixed modulation schemes in different fading conditions. The advantage of the adaptive modulation-based SWIPT transceiver is validated.