Solar System Research Articles

Observing gravitational waves with solar system astrometry

The subtle influence of gravitational waves on the apparent positioning of celestial bodies offers novel observational windows [1,2,3,4]. We calculate the expected astrometric signal induced by an isotropic Stochastic Gravitational Wave Background (SGWB) in the short distance limit. Our focus is on the resultant proper motion of Solar System objects, a signal on the same time scales addressed by Pulsar Timing Arrays (PTA). We derive the corresponding astrometric deflection patterns, finding that they manifest as distinctive dipole and quadrupole correlations or, in some cases, may not be present. Our analysis encompasses both Einsteinian and non-Einsteinian polarisations. We estimate the upper limits for the amplitude of SGWBs that could be obtained by tracking the proper motions of large numbers of solar system objects such as asteroids. We find that for SGWBs with negative spectral indices, such as that generated by Super Massive Black Hole Binaries (SMBHB), the constraints from these observations could rival those from PTAs. With the Gaia satellite and the Vera C. Rubin Observatory poised to track an extensive sample of asteroids — ranging from 𝒪(105) to 𝒪(106), we highlight the significant future potential for similar surveys to contribute to our understanding of the SGWB.

Forming Mercury from Excited Initial Conditions

Mercury is notoriously difficult to form in Solar System simulations, due to its small mass and iron-rich composition. Smooth particle hydrodynamics simulations of collisions have found that a Mercury-like body could be formed by one or multiple giant impacts, but due to the chaotic nature of collisions, it is difficult to create a scenario where such impacts will take place. Recent work has found more success forming Mercury analogues by adding additional embryos near Mercury’s orbit. In this work, we aim to form Mercury by simulating the formation of the Solar System in the presence of the giant planets Jupiter and Saturn. We test out the effect of an inner disk of embryos added on to the commonly used narrow annulus of initial material. We form Mercury analogues with core-mass fractions (CMFs) > 0.4 in ∼10% of our simulations, and twice that number of Mercury analogues form during the formation process but are unstable and do not last to the end of the simulations. Mercury analogues form at similar rates for both disks with and without an inner component, and most of our Mercury analogues have lower CMFs than that of Mercury, ∼0.7, due to significant accretion of debris material. We suggest that a more in-depth understanding of the fraction of debris mass that is lost to collisional grinding is necessary to understand Mercury’s formation, or some additional mechanism is required to stop this debris from accreting.

Feasibility of meteor surveying from a Venus orbiter

Meteor and bolide phenomena caused by the atmospheric ablation of incoming meteoroids are predicted to occur at the planet Venus. Their systematic observation would allow to measure and compare the sub-mm to m meteoroid flux at different locations in the solar system. Using a physical model of atmospheric ablation, we demonstrate that Venus meteors would be brighter, shorter-lived, and appear higher in the atmosphere than Earth meteors. To investigate the feasibility of meteor detection at Venus from an orbiter, we apply the SWARMS survey simulator tool to sets of plausible meteoroid population parameters, atmospheric models and instrument designs suited to the task, such as the Mini-EUSO camera operational on the ISS since 2019. We find that such instrumentation would detect meteors at Venus with a 1.5× to 2.5× higher rate than at Earth. The estimated Venus-Earth detection ratio remains insensitive to variations in the chosen observation orbit and detector characteristics, implying that a meteor survey from Venus orbit is feasible, though contingent on the availability of suitable algorithms and methods for efficient on-board processing and downlinking of the meteor data to Earth. We further show that a hypothetical camera onboard the upcoming EnVision mission to Venus similar to the ISS instrument should detect many times more meteors than needed for an initial characterisation of the large meteoroid population at 0.7 au from the Sun.

High-concentration hydrogen peroxide production by solar interfacial catalysis

Solar-driven catalytic synthesis of H2O2 is an ideal alternative to the anthraquinone method, but current photocatalysts still suffer from low activity and inefficient solar energy utilization. Here we presented an economic and efficient solar interfacial catalysis system (SICS) that incorporated photothermal–photocatalytic materials into commercial sponge to simultaneously generate the required heat and carriers for H2O2 production. We demonstrated its superiority over conventional particulate photocatalysis (PC) in photocatalytic H2O2 production. The SICS, located at the air–water interface, remarkably improve the activities of photocatalysts by efficient utilization of solar-converted heat. The produced H2O2 from SICS was reserved in the sponge and resulted in an ultrahigh concentration of 46 mM for per gram catalyst after 1 h solar irradiation. As thus, our application experiments confirmed that the SICS presented great advantages in organic pollutant (e.g. phenol and tetracycline) degradation compared with conventional PC. This work paves a new way for the industrialization of solar-driven catalysis.

Optimized model predictive control for solar assisted earth air heat exchanger system in greenhouse

Agricultural greenhouses play a crucial role in addressing the threat of climate change to agricultural systems. The greenhouse systems control exhibits nonlinear characteristics and large lag, both affecting the regulation of the greenhouse thermal environment. In this paper, a control strategy was designed to set the dynamic reference value of the control objective of the greenhouse model, considering factors such as solar radiation and the heating capacity of water body. A complete greenhouse model was developed using TRNSYS, and then the model predictive control building and optimization were implemented through MATLAB. The control effects of traditional proportional-integral-differentiation control, initial model predictive control, and optimized model predictive control were compared. The results showed that the regulation of greenhouse temperature was improved by 10.6 % in the coldest mouth compared to the conventional proportional-integral-differentiation control by the optimized model predictive control. During a typical cold month, the violation of constraints was reduced by 29.7 % by dynamically setting the target of the greenhouse with the optimized model predictive control. The performance of greenhouse climate control is enhanced by the proposed optimized model predictive control method, ensuring a stable regulation of the crop growth environment.

Effects of turbulent Prandtl number on supercritical carbon dioxide turbulent flow with high heat flux in vertical round tube

Supercritical carbon dioxide (sCO2) is a promising working medium for coal-fired power plants, high-temperature solar power systems, nuclear reactor systems, and fuel cells owing to its high efficiency and inertness. In these cases, the sCO2 is in a round tube under high temperature and pressure, far from the pseudo-critical point. Here, the thermophysical properties of sCO2 changes, resulting in large prediction errors. In this study, a conjugate heat transfer model with the k-ε turbulent model was created to analyze the tube performance of the sCO2, and the effects of turbulent Prandtl number (Prt) on the sCO2 turbulent flow with high heat flux were examined through experimental and numerical investigations. Prt had a considerable effect on the performance of the sCO2 turbulent flow far from the pseudo-critical point. The mean relative errors of the inner wall temperature and convective heat transfer coefficient were reduced by approximately 13% and 27%, respectively, when Prt was decreased from 1 to 0.55. For the sCO2 turbulent flow with a high heat flux, constant Prt values of 0.55–0.6 were applicable. The findings afford key insights for the development of sCO2 turbulent flow with high heat flux.

Novel cellulose-based films with highly efficient photothermal performance for sustainable solar evaporation and solar-thermal power generation

Solar-driven interfacial evaporation has received substantial attention in a variety of applications, including water purification, seawater desalination, and energy production. However, creating a straightforward, adaptable, and scalable method for correctly integrating hybrid solar-thermal systems continues to be a challenging task. Herein, we propose an economical, scalable, and environmentally friendly approach for achieving synergistic coupling of interfacial solar energy conversion for evaporation and low-grade thermal energy conversion to electricity by incorporating zinc oxide (ZnO) nanoparticle-modified MXene (ZNM- MXene) into cellulose nanofiber (CNF) films. The vacuum filtering approach produces CNF@ZNM-MXene composite films with enhanced photothermal conversion efficiency, capillary hydrophilicity, and thermal localization. Because of its rapid water transport capability, excellent sunlight absorption, and efficient solar-thermal conversion under 1 kW m−2 irradiance, the CNF@ZNM-MXene solar evaporator's evaporation rate reaches 1.27 kg m−2 h−1, and the solar-vapor conversion efficiency is as high as 82.15%, outperforming most previously reported solar evaporators. Moreover, when compared to a standalone thermoelectric (TE) module, the output power of the solar thermal conversion system coupled with a CNF@ZNM-MXene composite films and a TE module is boosted by 15.32 times. This work offers a practical and effective method for simultaneously capturing solar energy and desalinating saltwater.

Low-carbon scheduling of electricity consumption in wastewater treatment plant by using photovoltaic system

Sewage treatment as a high energy consumption industry, its electricity consumption accounts for 3 % of the total electricity consumption of society. That means significant greenhouse gas emissions. In the context of China's goal of “reaching carbon peak by 2030 and achieving carbon neutrality by 2060”, reducing the energy consumption of wastewater treatment systems has emerged as an important issue in recent years. In this paper, the GPS-X simulation software was employed to conduct a simulation study of a modified Anoxic-Aerobic-Oxic wastewater treatment plant (WWTP) in Wuhan, and the response surface methodology (RSM) was utilized to ascertain the interactive effects of DO, IRF, ERR, and SD on the effluent quality, thereby identifying the operational parameters that minimize energy consumption while maintaining satisfactory effluent quality. Additionally, the PVsyst software was employed to design the solar power generation system of the WWTP and analyze its power generation potential. On this basis, through the coupling of photovoltaic power, electricity load, time-of-use pricing, and the water quality simulation model, and taking the WWTP data in September as a case study, the electricity usage strategies under various illumination conditions were formulated. The aim is to maximize the use of photovoltaic power to reduce the cost and carbon emissions of the WWTP. The results show that the optimal combination of operational parameters, including an external reflux ratio of 0.3, the internal recycle flow of 50,000 m3/d, and the sludge discharge of 448 m3/d, resulted in a reduction in power of 208.5 kW, and after the combination optimization of operational parameters and electricity utilization, the operation cost of the WWTP in September was reduced by 40 % ∼ 60 %, and the carbon emission attributable to electricity was reduced by 30 % ∼ 50 %.

Effect of patterned condensation surface on the performance of a newly designed basin-type solar desalination unit

Evaporative solar desalination systems present a cost-effective solution for generating clean water from brine solutions or seawater. This study investigates the impact of condensation surface inclination, surface pattern, and wettability on the performance of a newly proposed basin-type solar desalination unit using computational fluid dynamics (CFD) based simulations. The proposed design of the system shows better performance in terms of water production compared to previously developed conventional units. It was observed that the wettability-based patterning with different arrangements on the condensation surface has a significant effect on the rate of water condensation. Five different cases of surface patterning on the condensation surface were considered. In one case, coatings of alternating hydrophobic and hydrophilic strips were considered (termed as Pattern-I, Pattern-II and Pattern-II for different cases based on the hydrophilic and hydrophobic coverages). In another case, small rectangular patches of hydrophilic (or hydrophobic) layers were coated on a hydrophobic (or hydrophilic) base substrate (termed as checkerboard Pattern-IV or V). The result shows 75.0% more efficiency for a checkerboard-based surface (Pattern-IV) and 150% more efficiency for a strip-based (Pattern-II) pattern than the pristine wettability surface of conventional design. Furthermore, the validation of the surface characteristics was performed based on available literature which implied satisfactory performance.

Energy transitions across household distributions in northern India

This paper investigates sustainable household energy transitions including a reduction in kerosene lamp use and increases in solar home systems and solar lanterns. We use a large and detailed survey of around 9,000 households in northern India in 2015 and 2018. Our key analytical insights focus on inequality across economic and wealth distributions, including the lack of major distributional changes between the two survey waves. We find that a positive relationship between economic resources and solar home system use is driven by the upper end of economic distributions. Kerosene use is also substantially lower for the top of the economic distribution, especially in the 2018 survey. In contrast, economic resources have a weak relationship with solar lantern use. Future policies can be devised with reference to our results showing a more robust relationship between assets, rather than income, and household energy transitions. The stronger influence of assets is evident for a range of asset variables and for a composite wealth index which we construct. Detailed analysis of socio-economic distributions has value for informing policy attempts to target support to constrained households.

Performance analysis of a novel solar Linear Fresnel concentrator system based on spectral beam splitting

Photothermal and photovoltaic are the most common and commercialized ways of utilizing solar energy. However, they cannot use solar energy efficiently. SBS (spectral beam splitting) technology is an efficient solar energy utilization technology that can realize the full spectrum utilization of solar energy. The current work involved: (1) Proposing a SBS-LFCs (linear Fresnel concentrator system) based on spectral beam splitting. In this system, the SBS photovoltaic panel replaces the conventional linear Fresnel concentrator lens, which can realize photovoltaic and photothermal utilization at the same time; (2) Developing a spectral splitting thin films configuration using the Needle method whose transmittance is higher than 90% against 380 nm-1100 nm band range; (3) Designing the SBS photovoltaic panel structure. The cover glass surface is covered with a SBS thin film. The SBS photovoltaic panel replaces the concentrator lens of LFCs; (4) Taking four typical days as examples, the annual power generation of a SBS linear Fresnel focusing system was predicted. The outcome indicates that the total conversion efficiency of solar thermal power in the system is 23.8%, 23.5%, 23.5%, and 23.6% on the spring equinox, summer solstice, autumn equinox, and winter solstice, respectively. Compared to conventional monocrystalline silicon cells, the photoelectric conversion efficiency has been improved by 14.6%, 12.8%, 12.5%, and 14.1%, respectively.

Numerical modeling of a novel solar cell system consisting of electron Transport material (ETM)/CaZrS3-based chalcogenide perovskites using SCAPS-1D software

In this study, a device simulation of CaZrS3 material is reported for the first time, which makes this new study interesting, using the one-dimensional solarcell capacitance simulator Scaps-1D. Therefore, we tried to propose low-cost Electron Transport Materials ETMs (TiO2, ZnO, and SnO2). The effect of thickness, doping concentration, working temperature, defect density, and back contact (C, Au, Ni, and Pt) on the device performance was studied. In order to enhance the cell Power Conversion Efficiency (PCE), optimization of the device design key parameters is performed. As a result, we have found that for Pt/CuO/CaZrS3/SnO2/FTO, Pt/CuO/CaZrS3/TiO2/FTO, and Pt/CuO/CaZrS3/ZnO/FTO the PCE parameters are 34.56%, 34.52%, and 33.5% respectively. We anticipate that our theoretical results will motivate photovoltaic researchers to experimentally actualize these materials and their SCs.

Design of a Stand-Alone Photovoltaic (PV) System for a Three-Bedroom Apartment in Mubi, Adamawa State, Nigeria.

In the world today, electricity is also among the essential basic amenities of every human being because it drives the socio-economic activities of any country. More than 1.3 billion of the populations across the globe are living with low or no source of electricity. The lack of accessibility to electric power to this population brought an existence of a wide gap in current energy sources and this affected the growth of such population mostly residing in remote settlements of developing nations. Electrical energy is a significant feature for the economic and developmental advancement in every nation. Even with the abundance of many sources of energy (conventional and non-conventional sources) around the world and in Nigeria, there are still problems in accessing electricity which could be attributed to its generation, transmission, or distribution. These challenges hinder the socio-economic advancement of a country. About 95 million (55 % of Nigeria's population) Nigerians are living with no supply of electricity and the total power/electricity produced, there is about 30-35 % loss in the generated energy from transmission and distribution. This research studied the possibility of electrifying a three-bedroom apartment in Mubi's high residential layout using a solar photovoltaic system through the adoption of HOMER Software. The parameters/data used in this research work were obtained from the basic appliances usually found in an average household and from works of literature on studies performed on energy utilization in some residential areas in Nigeria, taking into consideration their power ratings, quantity, and solar component prices. These and some design considerations like system fixed capital operation and maintenance cost of ₦ 4,000 per year, project lifetime of 20 years, system fixed capital cost, discount rate of 9 %, average solar radiation data, coordinate of Mubi, among other parameters were applied in the HOMER software for the design, simulation and optimized results obtained. The optimized results indicate that a solar PV array of 5 kW comprising 25 solar panels of 200 W each, 10 sets of 12 V / 220 Ah batteries, and a 5000 VA inverter with charger are sufficient to accommodate the load of 16.086 kWh/day. The cost of energy (COE) with a 100 % renewable fraction is ₦ 410.94 / kWh.

Energetic, Exergetic, Exergoeconomic, and Enviroeconomic Analysis of Solar Dish-Integrated Water Desalination System with Various Nanofluids

Global demand for freshwater is increasing due to population growth and water scarcity. Traditional desalination systems are characterized by their high energy consumption, resulting in low efficiency and elevated costs. It is crucial to explore sustainable and eco-friendly desalination system to address these problems. Present study explores the impact of Al2O3 and ZnO nanofluids on a solar dish integrated water desalination system (SWDS). Performance evaluation includes energy, exergy, economic, exergoeconomic, and enviroeconomic perspectives. Compared to SWDS with water, annual freshwater productivity increased by 20.13% (Al2O3) and 12.56% (ZnO). SWDS with Al2O3 nanofluid exhibited the highest energy and exergy efficiency at 20.76% and 4.32%, respectively. Energetic parameters revealed a minimum energy payback time of 0.91 years and a maximum energy production factor of 27.18 for SWDS with Al2O3 nanofluid. The lowest cost per liter (CPL) was US$0.050 for Al2O3 nanofluids, while the highest CPL was US$0.0547 for ZnO nanofluid. The maximum exergoeconomic parameter was 2.50 kWh/US$ for SWDS with Al2O3 nanofluid. SWDS with Al2O3 nanofluid demonstrated the highest net CO2 mitigation at 72.54 tonnes, with corresponding carbon credits of US$2124.08 (energy) and US$423.92 (exergy). The Al2O3 nanofluid-based SWDS demonstrated superior performance in energy and exergy perspective. Furthermore, Al2O3 nanofluid-based SWDS showed enhanced cost-effectiveness and environmental sustainability when compared to water-based SWDS.

Thermodynamic analysis of an evacuated tube solar collector system for industrial building application: A case study

In this study, a modified solar-Organic Rankine Cycle (ORC) assisted hydrogen production system for two different scenarios was experimentally investigated. In the study, evacuated tube solar collector (ETSC), ORC system, proton exchanger membrane electrolyzer (PEMe) unit is discussed with a holistic perspective. The presented work includes energy and exergy analysis of solar-ORC assisted hydrogen production. According to scenario 1 (S-1), only the case of hydrogen production from the installed system is considered. According to Scenario 2 (S-2), the both electrical energy and hydrogen production from the installed system is examined. As a result of the study, the energy efficiency in S-1 and S-2 operating modes was calculated as 9.553% and 16.02%, respectively. Additionally, the highest exergy efficiency for both scenarios was calculated as 6.129% in the S-2 scenario. Furthermore, hydrogen production amount of the S-1 and S-2 scenarios was calculated as 743.1 kg/annual and 371.5 kg/annual, respectively.

Annual performance evaluation of a hybrid concentrated solar–micro gas turbine based on off-design simulation

As the adoption of solar hybrid systems continues to rise due to their potential to compensate for the fluctuation of solar irradiation, it becomes imperative to accurately evaluate their performance, considering the variation of off-design conditions. This paper introduces a detailed analysis method for evaluating the annual performance of a solar-MGT system under transient boundary conditions for a whole-year operation range. A hybrid system of a micro gas turbine, recuperator, and solar dish is considered, and an off-design simulation model is developed and verified with available experimental results. Two different configurations for a recuperated cycle are considered, and simulations are conducted for a test case in Pretoria, SA. The results for Jun.21 and Dec.21 as low and high solar energy days are reported with more details to compare the configurations and demonstrate the effect of ambient temperature on the heat loss of the solar receiver and the overall performance of the system. The alternative configuration reduces heat loss with a lower temperature receiver but has higher fuel consumption compared to the conventional configuration. Operating strategies for different hours of operation from 1 h to 24 h per day are simulated for 365 days, based on real meteorological data, and compared with the operating in solar available hours. It is shown that the whole-year simulation of the system considering the variation of boundary conditions can change the estimation of fuel consumption by 25 %.

Carbon and economic prices optimization of a solar-gas coupling energy system with a modified non-dominated sorting genetic algorithm considering operating sequences of water-cooled chillers

To promote the continuous operating of solar energy systems and increase the proportion of renewable energy consumption, solar devices are often integrated with conventional energy systems to reduce greenhouse gas emissions. In this study, a solar-natural gas coupling system is constructed, utilizing solar photovoltaics, thermal collectors, and high-efficiency energy conversion devices. After modelling the energy system, the operating modes are illustrated considering working sequences of water-cooled devices. A modified genetic algorithm, which incorporates reverse learning, controlled elite, and dynamic crowding distance theory, is constructed to optimize the configurations of the proposed energy system, with the aim of minimizing carbon and economic prices of the products. The performance of the energy system is compared with different algorithms and cases, and the results demonstrate that the proposed optimization algorithm addresses the limitations of conventional methods, albeit with increased optimization times. Moreover, the proposed operating mode (Case 1) exhibits a stable performance, leading to a higher environmental and economic performance compared to conventional modes, with carbon and economic prices of 0.242 kg/kWh and 0.067 $/kWh, respectively. This study provides new insights into carbon footprints and economic performance evaluation of high-efficiency energy systems, offering valuable directions for future research in this field.

In Appreciation of Our 2023 Reviewers and Volunteers

AbstractIn JGR‐Planets, the peer review process is critical to ensuring that the published articles are based on sound scientific principles, follow state‐of‐the‐art techniques while acknowledging relevant prior results, and present exciting discoveries or novel understanding of the fundamental processes that affect solar system objects. JGR‐Planets covers a broad range of topics addressing every aspect of geoscience with the only requirement that the work addresses planetary processes. The wide breadth of topics published is reflected by our editorial team composed in 2023 of associate editors Adrian Brown, Jun Cui, Joel Davis, Leigh Fletcher, Matthias Grott, Ananya Mallik, Germán Martínez, Molly McCanta, Katarina Miljkovic, Naomi Murdoch, Ryan Park, Arianna Piccialli, Andrew Poppe, Beatrix Sánchez‐Cano, Laura Schaefer, Mariek Schmidt, Yasuhito Sekine, Kelsi Singer, Michael Sori, Norihiko Sugimoto, Sonia Tikoo, David Trang, and Zhiyong Xiao in addition to the editors who authored this note. We rely on the expertise of the community to vet the articles submitted to the journal. In 2023, JGR‐Planets benefited from 1,184 reviews provided by 731 unique volunteer referees. We also received help from 19 guest editors working on four active special collections. To these volunteers: We are truly grateful that you chose to dedicate your time and energy to evaluate manuscripts and to advise us on the suitability of each manuscript for JGR‐Planets, often suggesting ways to improve the papers. We know that all our volunteers juggle many duties, both professional and personal. On behalf of the entire editorial board of JGR‐Planets, we express our heartfelt gratitude to the many scientists who support this journal. Thank you! You are performing a valued service to this journal and to the community.

Inquiry-based astronomy in West Java secondary schools

This study investigates the presence and utilisation of inquiry-based activities in astronomy education within secondary science and physics classrooms. Employing document analysis, surveys, classroom observations, and interviews, the study comprehensively assesses the nature of inquiry activities, teachers’ experiences, integration of astronomy into curriculum, resources availability and science teachers’ perceived proficiency in astronomical observation skills. Findings from 50 secondary science and senior high physics teachers reveal coverage of the Solar System and Earth–Moon–Sun motion in secondary science, and integration of astronomy concepts like universal gravitation and Kepler’s laws into physics classrooms. However, inquiry-based astronomy teaching is limited, with only 10% of educators feeling proficient in telescope use and low adoption of virtual laboratories and simulations. The study underscores the necessity for adaptive inquiry-based activities in astronomy education to enhance science and physics classrooms, proposing direct and indirect celestial object observation, virtual inquiries, and hands-on simulations to bridge skill gaps and resource utilisation shortcomings, thus enriching astronomy education at the secondary level.

Optical Characteristics of Rectangular Cross-Section Torus Waveguide

The rectangular cross-section waveguide made of PMMA is designed to efficiently transfer solar radiation from the source to the receiver, whether it be a (solar cell or a thermal reservoir) by the total internal reflection of the radiation within the waveguide. The waveguide is designed with a torus, like the letters U and S, which provides greater flexibility to reach previously inaccessible areas with traditional waveguide shapes. To design the waveguide, the simulation program (ANSYS Zemax OpticStudio 2022) uses the analysis tool in the program (detector viewer). The optical efficiency of the system was calculated by varying a set of optical parameters, such as the radius of curvature of the waveguide, the width of the entrance aperture, and the angle of rotation. The results showed that the designed (U) model offers more design flexibility than the (S) model, enabling greater geometric freedom in solar system design and providing greater diversity in design based on its intended purpose without significantly affecting the efficiency of the system.