http://yetl.yabesh.ir/yetl1/handle/yetl/19043 2026-04-07T13:58:26Z 2026-04-07T13:58:26Z Lou, Chenyu Gao, Huiru Xu, Shuai Zhu, Liya http://yetl.yabesh.ir/yetl1/handle/yetl/4310615 2026-02-17T21:46:20Z 2025-01-01T00:00:00Z

A Novel Optical Efficiency Model for Heliostat Fields Based on 2D Boolean Operations Lou, Chenyu; Gao, Huiru; Xu, Shuai; Zhu, Liya The optimal design of the heliostat field is one of the fundamental issues in concentrated solar power generation. Due to the complexity of computing the shading and blocking, the accurate computation of optical efficiency of the heliostat field requires high computational resources. In this work, an optical efficiency model based on 2D Boolean operations was proposed, in which the heliostat, shading, and blocking objects were converted into planar polygons defined by boundaries and the planar polygons were reconstructed for Boolean operations (e.g., intersection, union, and difference). By comparing with the ray tracing method based on heliostat discretization and boundary mesh, it is shown that for the same accuracy requirement, the proposed method can greatly reduce the computation time. The method may serve as a powerful tool for the optimization design of complex heliostat fields.

2025-01-01T00:00:00Z Hufstedler, Esteban A. L. http://yetl.yabesh.ir/yetl1/handle/yetl/4310608 2026-02-17T21:46:05Z 2025-01-01T00:00:00Z

Evaluating Glint and Glare Hazards From Fields of Parabolic Mirrors Hufstedler, Esteban A. L. Reflected light from photovoltaic installations and concentrated solar power plants poses a significant risk to observers, manifesting as glint (momentary flashes) and glare (sustained brightness). These hazards are potentially magnified in heliostat fields, where curved mirrors require more detailed modeling. This article builds on existing glint/glare analysis methods by introducing improved models of the beam size and intensity from parabolic mirrors. Additionally, a novel approach is developed to aggregate the effects of multiple mirrors into a single “danger level.” These enhancements are used to evaluate the ocular hazard above the National Solar Thermal Test Facility. These tools offer improved fidelity and confidence in the results of optical risk analyses for solar energy installations.

2025-01-01T00:00:00Z Alqatamin, Ahmad Al-Khashman, Omar Ali Su, Jinzhan http://yetl.yabesh.ir/yetl1/handle/yetl/4310599 2026-02-17T21:45:41Z 2025-01-01T00:00:00Z

A Novel Heatsink for Optimizing Photovoltaic Cell Performance With Passive Cooling Using Perforated Wave-Shaped Fins Alqatamin, Ahmad; Al-Khashman, Omar Ali; Su, Jinzhan Photovoltaic (PV) systems convert solar energy into electricity with about 20% efficiency, while the remaining 80% dissipates as heat, reducing performance. Maintaining PV cells near 25 °C is crucial to avoid efficiency losses. This study explores a novel passive cooling design, photovoltaic perforated wavy-shape fins (PV-PWSFs), using ansys fluent simulations under solar irradiance (400–1000 W/m2) and airflow speeds (0.5–2.5 m/s). The PV-PWSFs system significantly reduced average PV temperatures, cooling them to 57.8 °C at 1000 W/m2, compared to 64.5 °C for photovoltaic perforated straight-shape fins (PV-PSSFs) and 83.3 °C without fins. At higher airflow speeds, the system achieved even lower temperatures, reaching 47.7 °C at 2.5 m/s. This cooling enhanced PV efficiency to 12.79% and boosted power output by 15.6% at 1000 W/m2. The wavy fins increased heat dissipation by enlarging the surface area and promoting turbulent airflow for improved convective cooling. Perforations facilitated better airflow distribution, reducing hotspots and ensuring uniform panel temperatures. Additionally, the study also analyzed the effects of fin wavelength and amplitude on performance. A wavelength of 10 cm and an amplitude of 1.5 cm provided optimal cooling by balancing heat transfer enhancement and flow resistance. These findings demonstrate that the PV-PWSF design effectively reduces operating temperatures, enhancing both the performance and lifespan of PV systems.

2025-01-01T00:00:00Z Michaelides, Efstathios E. http://yetl.yabesh.ir/yetl1/handle/yetl/4310592 2026-02-17T21:45:27Z 2025-01-01T00:00:00Z

Energy Efficiency and Grid-Independent Buildings Michaelides, Efstathios E. The proliferation of solar homes with photovoltaics and without energy storage promotes the electric power supply–demand mismatch and impedes the higher market adoption of renewable energy in buildings and the decarbonization of the electricity generation industry. Solar buildings with energy storage, the grid-independent buildings, will alleviate this problem. Computations have been performed to determine the required photovoltaic power and energy storage for such homes in a region where air conditioning is vital and consumes substantial electric energy. The methodology of the computations is based on the hourly matching of the electric power demand with solar energy supply considering the improved efficiency and conservation measure effects in the building. The aim is to determine the effect of efficiency measures on required infrastructure (nominal power, required storage, and dissipation) for the transition to renewables. The results show that higher energy efficiency and conservation measures in buildings will have beneficial future consequences by reducing the needed photovoltaics nominal power by 63% and the required energy storage by 73%. A related and welcome consequence is the reduction of dissipation in the storage–regeneration processes by 60%. The computational results strongly support the conclusion that energy efficiency and conservation measures in the households must proceed before or together with the transition to renewable power.

2025-01-01T00:00:00Z