The aim of this study was to conduct thermodynamic and economic analyses of a concentrated solar power (CSP) plant to drive a supercritical CO₂ recompression Brayton cycle. The objectives were to assess the system viability in a location of moderate-to-high temperature solar availability to sCO₂ power block and to investigate the role of thermal energy storage with 4, 8, 12, and 16 hours of storage to increase the solar share and the yearly energy generating capacity. A case study of system optimization and evaluation is presented of a city in Saudi Arabia. To achieve the highest energy production per unit cost, the heliostat geometry design integrated with a sCO2 Brayton cycle with a molten salt thermal energy storage (TES) dispatch system and corresponding operating parameters are optimized. A solar power tower (SPT) is a type of CSP system that is of particular interest in this research because it can operate at relatively high temperatures. The present SPT-TES field comprises of heliostat field mirrors, a solar tower, a receiver, heat exchangers, and two molten-salt TES tanks. The main thermo economic indicators are the capacity factor and the levelized cost of electricity (LCOE). The findings indicate that SPT-TES with a supercritical CO₂ power cycle is economically viable with 12 hours thermal storage using molten salt. The results also show that integrating of 12 hours-TES with a SPT has a high positive impact on the capacity factor of 60% at the optimum LCOE of $0.1078/kWh.

The present study describes the development and application of a model of the national electricity system for the Caribbean dual-island nation of Antigua and Barbuda to investigate the cost-optimal mix of solar photovoltaics (PVs), wind, and, in the most novel contribution, concentrating solar power (CSP). These technologies, together with battery and hydrogen energy storage, can enable the aim of achieving 100% renewable electricity and zero carbon emissions. The motivation for this study was that while most nations in the Caribbean rely largely on diesel fuel or heavy fuel oil for grid electricity generation, many countries have renewable resources beyond wind and solar energy. Antigua and Barbuda generates 93% of its electricity from diesel-fueled generators and has set the target of becoming a net-zero nation by 2040, as well as having 86% renewable energy generation in the electricity sector by 2030, but the nation has no hydroelectric or geothermal resources. Thus, this study aims to demonstrate that CSP is a renewable energy technology that can help assist Antigua and Barbuda in its transition to a renewable energy electric grid while also decreasing electricity generation costs. The modeled, optimal mix of renewable energy technologies presented here was found for Antigua and Barbuda by assessing the levelized cost of electricity (LCOE) for systems comprising various combinations of energy technologies and storage. Other factors were also considered, such as land use and job creation. It was found that 100% renewable electricity systems are viable and significantly less costly than current power systems and that there is no single defined pathway towards a 100% renewable energy grid, but several options are available.

A fully wicked ground source heat pipe (GSHP) is numerically employed and simulated to transfer thermal energy from the subsurface to ground surface pavements to reduce the environmental temperature fluctuations in the pavement, thereby reducing thermal stresses and increasing pavement life. The GSHP can also reduce or eliminate snow and ice buildup on pavement surfaces. Each single GSHP was modeled in a two-dimensional axisymmetric cross-section using COMSOL software, which employs a finite element method. The modeled GSHP consisted of two parts: a disk shape buried below the pavement surface, connected to a cylindrical part embedded in a vertical underground borehole. The GSHP finite element model was validated against published experimental heat pipe data. The simulation results demonstrated that the thermal behavior of the heat pipe system during the cold season could reduce the temperature fluctuations on the pavement surface in six various climate zones. The addition of insulation along the vertical length of the heat pipe was found to significantly reduce heat loss between the heated and unheated pavement surfaces. The low thermal conductivity of the pavement material decreases the performance of the GSHP system. Finally, the maximum-minimum normalization method was applied to the parametric analysis to normalize and compare results for future use.

The present study describes the development and application of a computer model of the national electricity system for the Caribbean dual-island nation of Antigua and Barbuda to investigate the cost-optimal mix of solar photovoltaics (PV), wind, and in the most novel contribution, concentrating solar power (CSP). These technologies, together with battery and hydrogen energy storage, can enable the aim of achieving 100% renewable electricity and zero carbon emissions. The motivation for this study was that while most nations in the Caribbean rely largely on diesel fuel or heavy fuel oil for grid electricity generation, many countries have renewable resources beyond wind and solar energy. Antigua and Barbuda generates 93% of its electricity from diesel-fueled generators and has set targets of becoming a net-zero nation by 2040 and having 86% renewable energy generation in the electricity sector by 2030, but the nation has no hydroelectric or geothermal resources. The modeled, optimal mix of renewable energy technologies presented here was found for Antigua and Barbuda by assessing the levelized cost of electricity (LCOE) for systems comprising various combinations of energy technologies and storage. Other factors were also considered, such as land use and job creation. It was found that 100% renewable electricity systems are viable and significantly less costly than current power systems, and that there is no single defined pathway towards a 100% renewable energy grid, but several options are available.

Photovoltaic–thermal (PVT) collectors often experience limited heat extraction under laminar cooling conditions, and the influence of controlled flow pulsation on full-scale PVT performance has not been clearly established. This study experimentally investigates a water-cooled PVT system operated under pulsating flow using an indoor solar simulator to quantify its thermal and electrical response. Flow pulsations were generated using a solenoid valve at frequencies of 0.25, 0.5, 1, and 2 Hz across inlet flow rates of 1–4 L/min, with average irradiance maintained between 700 and 800 W/m². System performance was benchmarked against uncooled and continuous-flow reference cases. Pulsating operation reduced the PVT surface temperature and produced a clear enhancement in thermal performance relative to continuous flow, while electrical efficiency exhibited a smaller but consistent improvement that followed the same thermal trend. A pulsation frequency of 0.5 Hz yielded the most favorable results, achieving thermal efficiencies exceeding 50% at higher flow rates without any measurable increase in average pressure drop. Electrical efficiency stabilized at approximately 9.82%, slightly higher than that obtained under continuous-flow operation. The results indicate that low-frequency pulsating flow can significantly improve thermal energy extraction in PVT systems under controlled conditions, with modest associated electrical gains, and provide a basis for further investigation of flow-modulation strategies for thermally driven PVT applications.