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Concentrated solar power (CSP) has gained traction for generating electricity at high capacity and meeting base-load energy demands in the energy mix market in a cost-effective manner. The linear Fresnel reflector (LFR) is valued for its cost-effectiveness, reduced capital and operational expenses, and limited land impact compared to alternatives such as the parabolic trough collector (PTC). To this end, the aim of this study is to optimize the operational parameters, such as the solar multiple (SM), thermal energy storage (TES), and fossil fuel (FF) backup system, in LFR power plants using molten salt as a heat transfer fluid (HTF). A 50 MW LFR power plant in Duba, Saudi Arabia, serves as a case study, with a Direct Normal Irradiance (DNI) above 2500 kWh/m2. About 600 SM-TES configurations are analyzed with the aim of minimizing the levelized cost of electricity (LCOE). The analysis shows that a solar-only plant can achieve a low LCOE of 11.92 ¢/kWh with a capacity factor (CF) up to 36%, generating around 131 GWh/y. By utilizing a TES system, the SM of 3.5 and a 15 h duration TES provides the optimum integration by increasing the annual energy generation (AEG) to 337 GWh, lowering the LCOE to 9.24 ¢/kWh, and boosting the CF to 86%. The techno-economic optimization reveals the superiority of the LFR with substantial TES over solar-only systems, exhibiting a 300% increase in annual energy output and a 20% reduction in LCOE. Additionally, employing the FF backup system at 64% of the turbine's rated capacity boosts AEG by 17%, accompanied by a 5% LCOE reduction. However, this enhancement comes with a trade-off, involving burning a substantial amount of natural gas (503,429 MMBtu), leading to greenhouse gas emissions totaling 14,185 tonnes CO₂ eq. This comprehensive analysis is a first-of-a-kind study and provides insights into the optimal designs of LFR power plants and addresses thermal, economic, and environmental considerations of utilizing molten salt with a large TES system as well as employing natural gas backup. The outcomes of the research address a wide audience including academics, operators, and policy makers. [ABSTRACT FROM AUTHOR]

This study aims to experimentally evaluate the impact of a double-sided microporous layer coating on gas diffusion layers in terms of their key properties and fuel cell performance, in comparison to conventional single-sided coated gas diffusion layers (GDLs). Vulcan black and Ketjenblack were used as the carbon black materials. This was to investigate the sensitivity of the results with respect to the type of carbon black used. The results showed that the in-plane electrical conductivity is almost insensitive to microporous layer (MPL) loading and carbon black type. Furthermore, the electrical conductivity of all the MPL-coated GDLs are slightly lower than that of the uncoated GDL. The Ketjenblack black MPL samples were found to demonstrate higher gas permeability than the Vulcan black samples. The addition of the MPL resulted in a favourable shift in pore size distribution, with prominent micropores observed in both single- and double-sided MPL-coated GDLs. Contact angle measurements indicated a slight increase in the hydrophobicity with the addition of a microporous layer, but without significant differences between carbon black types or loading levels. Cross-sectional SEM images showed that there was a higher level of MPL penetration into the carbon substrate for the GDLs coated with Vulcan black as compared to a Ketjenblack coating. In situ fuel cell testing demonstrated the superior performance of the double-sided Vulcan black MPL-coated GDL under high humidity conditions, while the single-sided Vulcan black MPL-coated GDL exhibited better performance at low humidity conditions. All the above findings have been thoroughly discussed and justified. [ABSTRACT FROM AUTHOR]

A new three-dimensional numerical model of a polymer electrolyte fuel cell (PEFC) with a single straight channel was developed to primarily investigate the important impact of the double-sided microporous layer (MPL) coating on the overall performance of the fuel cell and the distribution of the current and the oxygen concentration within the cathode gas diffusion layers (GDLs). Realistic experimentally estimated interfacial contact resistance values between the gas diffusion layer and each of the bipolar plates and the catalyst layer values were incorporated into the model, and parametric studies were performed. The results showed that the double-sided MPL coating could significantly improve the fuel cell performance by up to 30%. Additionally, it was shown that the neglect of the contact resistance between the MPL and the catalyst layer could overestimate the fuel cell performance by up to 6%. In addition, the results showed that the fuel cell performance and the distribution of the current and oxygen are more sensitive to the porosity of the MPL facing the bipolar plate than the porosity of the MPL facing the catalyst layer. All the above results are presented and critically discussed in detail. [ABSTRACT FROM AUTHOR]