Hybrid GO-MXene nanofluids in 3D oscillating heat pipes for efficient urban PV cooling: Improved energy, exergy, and economic performance

Photovoltaic (PV) panels play a pivotal role in advancing renewable energy adoption by offering a clean and sustainable alternative to fossil fuels. However, elevated operating temperatures diminish PV cell performance, reducing energy output and accelerating material wear. This research evaluates the cooling efficiency of a PV panel equipped with a three‐dimensional oscillating heat pipe (3D‐OHP) integrated with hybrid nanofluids consisting of graphene oxide–copper oxide (GO–CuO), carbon nanotube–CuO (CNT–CuO), and multiwalled CNT–CuO (MWCNT–CuO). The OHP is charged with two concentrations of each nanofluid, specifically 0.1 and 0.2 g/L, to evaluate their impact on the thermal management of the PV panel. The study involved experimental tests using two PV panels: one equipped with a 3D‐OHP as the cooled panel and the other as a reference panel under identical environmental conditions. Hybrid nanofluids were prepared by dispersing nanoparticles in a base fluid, and their thermal properties were characterized prior to use. Energy and exergy analyses quantify the enhancements in thermal efficiency and the reduction in entropy generation. Experimental results reveal that CNT–CuO with a concentration of 0.2 g/L remarkably improves the electrical power output by 12.07%, outperforming other studied systems with the maximum exergy efficiency of 31.2%. The findings also highlight notable gains in first‐law efficiency. Furthermore, the levelized cost of energy (LCOE) and levelized cost of storage (LCOS) are analyzed, demonstrating the economic feasibility of hybrid nanofluid‐based cooling for PV systems.

The Cryogenic Flux Capacitor (CFC) is a cold, dense energy storage core that is being studied in the cryo-compressed, about 300 bar and 80K, region of gaseous hydrogen (GH2) storage and liquid hydrogen (LH2) region near the normal boiling point. Hydrogen storage is improved by physically bonding the molecules within the nanoscale pores of the aerogel composite blanket material. The process of bonding or debonding is governed by principles of physical adsorption (physisorption) and thermodynamics. The large surface area afforded by the nanoporous aerogel (∼1,000 m2/g) allows its storage performance to easily exceed capacities of high-pressure GH2 storage for an equivalent volume. With the integrated aerogel, subscale tests have shown that storage is increased by about 36% over a simple tank filled with GH2 at the same operating temperature and pressure. For LH2 conditions, the CFC is shown to operate at improved densities, but testing is ongoing. For the techno-economic analysis (TEA), the source of hydrogen is compared between onsite steam methane reforming (SMR) and onsite solar photovoltaic (PV) panels providing power to electrolyzers to produce green GH2. The TEA compares pure hydrogen produced at a small scale for a 25 MW power system and at a large scale in a 500 MW power system. The system allowed for hydrogen imports and exports at a set price with a tank sized for 10 hours of power production. The two power producing technologies are a combined cycle gas turbine (CCGT) and hydrogen fuel cells. The SMR system uses natural gas as an input and includes a carbon capture and storage (CCS) system. The levelized cost of electricity (LCOE), levelized cost of hydrogen (LCOH), and levelized cost of storage (LCOS) are developed based on the capital cost and operating cost of the systems. The results are shown for current costs using a 2021 benchmark and DOE projections for cost improvements by 2030. The TEA showed that onsite hydrogen generation from SMR has an LCOH of about 1.4 to 2 USD per kg over the life of the plant and the PV hydrogen production LCOH is about 5.2 to 5.5 USD per kg. The LCOS of conventional GH2 systems is estimated to be $210/MWh and cost of storage for LH2 systems is $205/MWh for fuel cell systems and $249/MWh for CCGT systems. CFC improved the LCOS of all these systems to $198/MWh, $191/MWh and $233/MWh respectively. The LCOE also improved with conventional systems between $171/MWh and $228/MWh improved by CFC to between $167/MWh and $212/MWh. Using projections for improvement in costs following DOE’s goals by 2030, green hydrogen improved to as low as $78/MWh LCOS and LCOE for conventional cases. CFC improved over conventional storage with the lowest LCOS being $62/MWh and the lowest LCOE being $73/MWh. These results correspond to an LCOH of $2/kg. Finally, the TEA shows how LCOE is improved for hydrogen conditioning and storage over conventional systems and caverns in the 10 to 50 hour range.

This study investigates the impact of uncertainty in building operation patterns on the design and techno‐economic performance of solar photovoltaic (PV) systems in a commercial building in a hot arid region in Abu Dhabi, UAE. Utilizing the Design‐Builder software, a model of a commercial hotel building was developed and calibrated to assess its energy demand. Three distinct operational scenarios—Austere, Baseline, and Wasteful—were analyzed in this study, each considering both grid‐connected PV systems with and without energy storage solutions. The study employed sensitivity analyses to understand how variations in modeling inputs affect the levelized cost of energy (LCOE) and the levelized cost of storage (LCOS). The findings reveal significant variations in LCOE and LCOS across different scenarios, in which the minimum (LCOE) can be achieved at $0.165/kWh for the Baseline Case, $0.191/kWh for the Austere Case, and $0.162/kWh for the Wasteful Case, while the minimum (LCOS) can reach $0.30/kWh for Baseline case, $0.55/kWh for Austere case, and $0.19/kWh for Wasteful Case, underscoring the necessity of tailored PV system designs to optimize performance and economic feasibility. This study contributes to the growing body of knowledge of sustainable building energy solutions, highlighting the importance of incorporating operational uncertainties into the planning and design of renewable energy systems.

Harvesting energy horizons: Bifacial PV and reversible fuel cells unite for sustainable building solutions

This study investigates the technoeconomic feasibility of integrating photovoltaic (PV) and wind turbine-based renewable energy systems with various storage technologies for a university lodging consisting of 50 houses in İzmir, Türkiye. To address the rising demand for sustainable and cost-effective residential energy solutions, four energy storage options—lead-acid, lithium-ion, vanadium redox flow (VRF), and hydrogen-based systems—were evaluated. Their economic performance was assessed using indicators such as Levelized Cost of Electricity (LCOE), Levelized Cost of Storage (LCOS), and Net Present Value (NPV). The annual electricity load profile was constructed hourly, reflecting monthly consumption and user behavior. PV and wind energy outputs were estimated using PV-Sol software and turbine power curves, respectively. A model was developed in MATLAB, targeting a Loss of Power Supply Probability (LPSP) below 1% over 20 years. Results showed that vanadium redox flow batteries had the best economic performance, due to their long lifespan and low capital cost, achieving the lowest LCOE (0.31 $/kWh), LCOS (0.24 $/kWh), and highest NPV (0.42 million $). PV-based systems were more favorable than wind-based ones, mainly due to wind turbines' higher costs and lower capacity factors in the region. Sensitivity analysis highlighted that storage cost, LPSP, grid electricity price, and interest rate are the most influential parameters. This research provides valuable guidance for developing economically viable and technically reliable off-grid renewable energy systems, supporting informed decision-making by researchers and policymakers working on localized energy transition strategies.

Techno-economic analysis of long-duration energy storage and flexible power generation technologies to support high-variable renewable energy grids

The Assessment of Off-Grid Photovoltaic (PV) Systems for Rural Electrification in Indonesia

This research introduces a ‘Hydrogen Interconnector System’ (HIS) as a novel method for transporting electrical energy over long distances. The system takes electricity from stranded renewable energy assets, converts it to hydrogen in an electrolyser plant, transports hydrogen to the demand centre via pipeline, where it is reconverted to electricity in either a gas turbine or fuel cell plant. This paper evaluates the competitiveness of the technology with High Voltage Direct Current (HVDC) systems, calculating the following techno-economic indicators; Levelised Cost Of Electricity (LCOE) and Levelised Cost Of Storage (LCOS). The results suggest that the LCOE of the HIS is competitive with HVDC for construction in 2050 with distance beyond 350 km in case of all scenarios for a 1 GW system. The LCOS is lower than an HVDC system using large scale hydrogen storage in 6 out of 12 scenarios analysed, including for construction from 2025. The HIS was also applied to three case studies, with the results showing that the system outperforms HVDC from LCOS perspectives in all cases, and has 15%–20% lower investment costs in 2 studies analysed.

Fabrication of silica-decorated graphene oxide nanohybrids and the properties of composite epoxy coatings research

This paper presents a modeling and analysis of the levelized cost of electricity (LCoE) related to solar Photovoltaic (PV) power plants. As the PV matures, the economic feasibility of PV projects is increasingly being evaluated using the LCoE. Regulation of the Minister of Energy and Mineral Resources of the Republic of Indonesia Number 19 the Year 2016 concerning the purchase of electricity from PV Power Plants by PT PLN (Persero) for On-Grid PV in East Nusa Tenggara with a purchase of 0.23 US$ / kWh, but the purchase price of electricity for Off-Grid PV system have not been determined. The aim of this study was to analyze LCoE for PV systems so that could help policymakers and PV investors to calculate the cost of providing PV systems for rural areas, especially in Kupang Regency. The research method uses an LCoE modeling approach. The results showed that LCoE PV On-Grid system at the level of 0.19-0.21 US$/kWh, and LPoE at the level of 0.21-0.23 US$/kWh. LCoE Off-Grid PV system at the level of 0.29-0.31 US$/kWh, and LPoE at the level of 0.31-0.33 US$/kW. The result from modeling PV On-Grid System, estimated by 2030, LPoE at the maximum level of 0.24 US$/kWh.

Hydrogel dressings have received extensive attention for the skin wound repair, while it is still a challenge to develop a smart hydrogel for adapting the dynamic wound healing process. Herein, we develop a novel graphene oxide (GO) hybrid hydrogel scaffold with adjustable mechanical properties, controllable drug release, and antibacterial behavior for promoting wound healing. The scaffold was prepared by injecting benzaldehyde and cyanoacetate group-functionalized dextran solution containing GO into a collection pool of histidine. As the GO possesses obvious photothermal behavior, the hybrid hydrogel scaffold exhibited an obvious stiffness decrease and effectively promoted cargo release owing to the breaking of the thermosensitive C=C double bond at a high temperature under NIR light. In addition, NIR-assisted photothermal antibacterial performance of the scaffold could be also achieved with the local temperature rising after irradiation. Therefore, it is demonstrated that the GO hybrid hydrogel scaffold with vascular endothelial growth factor (VEGF) encapsulation can achieve the adjustable mechanical properties, photothermal antibacterial, and angiogenesis during the wound healing process. These features indicated that the proposed GO hybrid hydrogel scaffold is potentially valuable for promoting wound healing and other biomedical application.

Solar energy is a ubiquitous renewable resource for photovoltaic (PV) power generation; however, higher operating temperatures significantly reduce the efficiency of PV modules, impacting their electrical output and increasing the levelized cost of energy (LCOE). This study aims to enhance conventional PV systems’ electrical efficiency and annual energy recovery while reducing the LCOE through thermal management using microchannel heat sinks (MCHSs) under forced convection. A 600 W monocrystalline PV module was analyzed, recognizing an efficiency reduction of ~20% under actual operating conditions due to thermal effects, with the surface temperature reaching up to 63.76°C without cooling. In addition, analytical calculations were used to determine an incident solar irradiance of 957.33 W/m 2 for an industrial location in Lahore, Pakistan. Similarly, computational fluid dynamics (CFDs) simulations were conducted using single and dual‐layer MCHSs configurations with water as the coolant at inlet velocities ranging from 0.01 to 1.0 m/s. The dual‐layer MCHSs significantly reduced the PV module’s surface temperature from 63.76 to ~25.65°C at an inlet velocity of 1.0 m/s, achieving a temperature reduction of 38.11°C. This thermal management increased the electrical efficiency from 18.33% (without cooling) to 22.27%, an efficiency gain of ~4%. The annual energy recovery improved substantially; at 1.0 m/s, the dual‐layer configuration increased the annual energy output by 227,954 kWh/year (about 21.89%) compared to the no‐cooling scenario, reaching 1,269,131 kWh/year. Furthermore, the LCOE was reduced to as low as 6.27 PKR/kWh over a 30‐year operational lifespan at lower velocities, demonstrating improved cost‐effectiveness. Meanwhile, optimal velocity was identified between 0.2 and 0.5 m/s, balancing thermal performance and economic viability. Finally, this study concludes that thermal management using dual‐layer MCHSs effectively enhances PV module efficiency, increases annual energy recovery, and reduces LCOE, contributing to sustainable and economical solar energy integration in industrial applications.

Today, photovoltaic (PV) power generation accounts for a relatively small proportion of total power generation in China. If photovoltaic power can achieve grid parity, it can replace the original traditional thermal power generation, which has positive significance on the environment. The Levelized Cost of Energy (LCOE) is the main general economic indicator for the evaluation of power generation technology in the world. Based on the traditional LCOE evaluation model and considering the shortcomings of the previous LCOE evaluation models, the cost of photovoltaic power generation is refined in this paper. The cost of the taxation with calculating the depreciation, the loss, and the income of the Clean Development Mechanism (CDM) are taken into consideration. Hence, a more accurate and more comprehensive LCOE model is presented. Moreover, combined with other investment indicators, a photovoltaic power generation benefit model corresponding to the current development status is proposed. Taking a 3-MW distributed photovoltaic power station project in Nanjing as a case study, the sensitivity analysis of factors that affect the benefit of photovoltaic power generation is carried out to further explore the feasibility of photovoltaic power to grid parity.

We investigated the effect of different spray-coating parameters on the electro-optical properties of Ag nanowires (NWs). Highly transparent and conductive Ag NW–graphene oxide (GO) hybrid electrodes were fabricated by using the spray-coating technique. The Ag NW percolation network was modified with GO and this led to a reduced sheet resistance of the Ag NW–GO electrode as the result of a decrease in the inter-nanowire contact resistance. Although electrical conductivity and optical transmittance of the Ag NW electrodes have a trade-off relationship, Ag NW–GO hybrid electrodes exhibited significantly improved sheet resistance and slightly decreased transmittance compared to Ag NW electrodes. Ag NW–GO hybrid electrodes were integrated into smart windows based on polymer-dispersed liquid crystals (PDLCs) for the first time. Experimental results showed that the electro-optical properties of the PDLCs based on Ag NW–GO electrodes were superior when compared to those of PDLCs based on only Ag NW electrodes. This study revealed that the hybrid Ag NW–GO electrode is a promising material for manufacturing the large-area flexible indium tin oxide (ITO)-free PDLCs.

Quantitative analysis of fluid motion in an oscillating heat pipe (OHP) is essential to better understand fluid flow and heat transfer mechanisms in an OHP. Two copper OHPs filled with water and acetone respectively were investigated by a neutron imaging technique to visualize the fluid motions in the OHP. Temperatures on the OHP surface were measured while neutron images were taken simultaneously. Algorithms to determine the degree of activity and the interface passing count were developed to analyze fluid motions quantitatively from the neutron images. Then, the degree of activity and the interface passing count were compared with temperatures. The results showed that there are patterns of temperature change before and after start-up of the oscillation motions. The acetone OHP showed better thermal performance at a similar heat input, while the water OHP showed better thermal performance at a similar degree of activity. Interfaces in the acetone OHP oscillate more frequently and travel further. Low latent heat at low heat input, low viscosity, and high thermal conductivity are preferred for the working fluid to achieve better thermal performance.