Applied Solar Energy最新文献

The daily performance and efficiency of a horizontally positioned flat-plate solar collector (FPSC) in pulsed mode, periodic filling and draining of the coolant upon reaching a predetermined average temperature, are examined. A one-dimensional non-stationary numerical thermal model and calculation program were developed, taking into account the FPSC’s key parameters, variations in solar radiation level, and outdoor air temperature. Its daily efficiency and performance were estimated at various hot water heat removal temperatures in summer. The obtained data can be used, as a first approximation, to estimate the FPSC’s daily efficiency and performance in normal operation. The FPSC’s pulsed mode of operation is of independent importance and allows for simplification of the receiver design, reducing the number of channels and eliminating the requirement for low velocities and uniform coolant flow within the FPSC.

To cope with the advancement of energy demand and environmental challenges, and to solve the issues of unstable and limited efficiency of single energy supply, a thermophotovoltaic model complementary to solar energy and fuel energy is studied and constructed. To analyze its energy conversion process, the Brayton cycle is innovatively introduced by combining solar energy and fuel energy to study energy conversion. The findings denoted that when the solar irradiance increased from 200 to 1000 W/m², the fuel compensation flow rate decreased from 1.1 m³/h to 0, the total input thermal energy increased from 32.5 to 43.1 kW, and the output electrical power increased synchronously from 3.9 to 7.1 kW. The total input thermal energy was positively correlated with the output electrical power, ensuring the coordinated change of system energy input and output. Under clear and cloudy conditions (700 W/m²), the model had the highest output power of 5.9 kW and a total system efficiency of 19.2%, with a solar energy contribution rate of 82.3%, reflecting the high efficiency of solar energy dominance. Although the solar energy contribution rate decreased to 45.6% under cloudy conditions (300 W/m²), the output power of 4.8 kW and total efficiency of 18% were still better than the rated fuel conditions (4.7 kW, 16.9%). The power fluctuation amplitude of the three operating conditions was ≤±2.1%, the battery temperature fluctuation was ≤±3.2%, and the fuel thermal energy utilization rate exceeded 89%, indicating that the model has high efficiency, stability, and high fuel utilization rate under different operating conditions. The research findings can provide theoretical support and practical reference for the design of distributed energy systems and the optimization of multi-energy complementary energy technologies.

Perovskite materials have generated considerable excitement owing to their remarkable properties and have become highly desirable materials for photovoltaics, sensors, and environmental remediation. Unlike conventional materials, their unique optoelectronic features, large charge-carrier mobility, tunable bandgap, and low-cost synthesis are interesting alternatives. Perovskite solar cells have significantly advanced the photovoltaic industry, emerging as a highly promising technology with power conversion efficiencies comparable to those of conventional silicon-based solar cells. Perovskite materials are highly sensitive to environmental factors such as gases and humidity and have been widely explored for sensing applications, including the detection of biological molecules. This means perovskite solar cells can be used in healthcare and for checking the environment. Perovskite materials are highly sensitive to environmental stimuli, making them suitable for applications such as sensing and optoelectronic devices. Perovskite-based photocatalysts may also play a significant role in environmental cleaning, such as in water purification and pollutant elimination. This paper includes a comprehensive overview of the advances of perovskite materials driven by the sustainable energy technologies, environment protection and sensor devices. These challenges of stability, toxicity, and mass production are also addressed with possible solutions for future advancements.

This study proposes and validates a differentiated methodology for assessing the grid-induced operational availability of a small-scale grid-connected photovoltaic power plant operating in a low-voltage distribution network in Uzbekistan. The case study is a PV plant installed in the Khatyrchi district of the Navoi region, equipped with a 10-kW grid-connected inverter and a 10.7 kWp photovoltaic array. Based on a full-year monitoring dataset for the leap year 2024, this study analyzed the annual energy generation, protective trip logs, voltage parameters, and structure of generation interruption events. The system generated 13894.7 kWh of electricity, corresponding to 1389.5 kWh/(kW·year) when normalized to the inverter rated power and 1298.6 kWh/(kWp·yr) when normalized to the PV-array peak power. The results indicate no evidence of significant underperformance of the photovoltaic subsystem. The 613 recorded events with a total duration of 306.5 h are interpreted not as proven equipment failures but as protective trips or generation interruptions caused by external grid conditions and inverter protection logic. Calendar availability was 96.51%, whereas availability within the 2900-h potential solar-generation window was 89.43%. Overvoltage in the low-voltage network was the dominant unavailability factor, accounting for 433 events or 70.6% of all interruptions. Scenario analysis shows that reducing overvoltage-related trips by 50–75% could increase solar window availability to 93.16–95.03%. The practical contribution of this study is an operational energy audit algorithm that separates grid-induced unavailability from equipment-related failures and supports technically justified measures to reduce generation losses.

Sustainable production of distilled water using solar desalination systems is becoming more attractive in recent years. Many researchers are trying to enhance the efficiency of such systems. In this study, an improved Parabolic Dish Solar Water Desalination System (PDSWDS) is developed utilizing solar tracking system and finned tube to produce distilled water. The improved solar system consists of solar collector dish to collect solar energy and reflect it to a still tank (receiver) that has the sea water and the system tested in the hot environmental conditions of Iraq. Due to the increased concentration of solar radiation, the temperature is increased inside the still tank causing the water to evaporate. To increase the condensation rate of water vapors, fines are provided over the surface along the length of the main receiver. Sun tracking system is equipped with the dish collector to enhance the efficiency of the solar desalination system. The system used to provide 40 to 50 L of pure water per day, assuming that the structure works about 8 h per day. Results showed increase in temperature of the still tank by 120°C when sun tracking system was employed compared with the system without it in which temperature reached to 71°C. The overall findings of this study show that the thermal efficiency increased by 30% than the manual tracking system and using fins in the solar desalination system was expanding the condensation of the desalination water even in the high ambient temperature in summer.

One of the main elements contributing to heat loss in buildings is the exterior envelope, which can be improved by employing passive solar systems. This research aims to investigate the Barra–Costantini system’s performance through simulation to obtain the best thermal performance with varying system characteristics, enhance thermal comfort, and reduce energy demand. Three types of glass—single-layer, two-layer, and three-layer—along with various channel dimensions (0.05, 0.1, and 0.15 m) and vent configurations were simulated in a residential building in Mashhad. For a room with a volume of 33.6 m³, the maximum heat gained with a 15 cm depth channel and single-layer glass resulted in an energy saving of 29.1%. The room temperature did not exceed 2°C with this system. However, this system alone cannot provide thermal comfort for Mashhad. The level of thermal comfort, as indicated by the Predicted Mean Vote index in October, with and without this system, is –1.6 and –2.06, respectively. Thermal comfort is improved during hot periods of the year by keeping external vents open during the day with an open roof vent at night instead of keeping all vents open throughout the day and night. Additionally, an increase in the height of the Barra–Costantini channel resulted in a decrease in the amount of heat gained.

This research article evaluates the performance of an Inverted Solar Collector (ISC) dryer for drying Sandfish in the Sahara region of Algeria (El-Oued City). Experimental studies compared an ISC dryer equipped with copper fins (CF) and paraffin wax (PCM) latent heat storage to an ISC dryer without CF-PCM, as well as to natural sun drying. Performance assessment considered both thermal efficiency and product quality. Sandfish with an initial moisture content of 73.18% were dried to a final moisture content of 11.34% (wet basis) in 43 h using the ISC dryer with CF-PCM, in 55 h using the ISC dryer without CF-PCM and over 100 h with natural sun drying. Results demonstrate a reduction in drying time of 27.90% compared to the ISC dryer without CF-PCM and up to 100% compared to natural sun drying. Additionally, solar drying enhanced the water, ash, protein, and lipid content of the dried Sandfish. Experimental findings revealed that the dried Sandfish contained 55.7% protein and 13.4% lipids, compared to 19.6 and 2.8%, respectively, in fresh Sandfish. From a nutritional quality perspective, the ISC dryer with CF-PCM proved to be the most effective method for Sandfish preserving.

Many researchers have turned to studying and developing vortex technologies for generating clean electrical energy. Vortex technologies generate an upward swirling air stream when operating in a moderate temperature range. The conventional air solar collector with a swirling engine is inadequate for creating and keeping updrafts by a previous design. The solar air vortex generator (SAVG) is one of the new alternative energies utilising solar energy to create artificial vortices (AV). The principle of its operation is similar to that of the solar updraft tower (SUT) plan. The research sought to propose, design, and optimise an artificial air vortex generator (AAVG) system by performing a set of calculations using the ANSYS 2024 R1 simulation software. Therefore, there are two aims in this research the first one is the effect of the engine diameter of the solar air vortex generator (SAVG) system in one air inflow slot and the second aim is to study the effect of the number of air inflow slots on artificial air velocity vortex flow behaviour inside the (SAVG) model in single guide blades, these facts were not mentioned in previous studies. Reducing the diameter of the solar air vortex generator (SAVG) system in one slot inflow for [36] by 50% of its dimension can generally increase its kinetic energy, specifically its rotational kinetic energy reaching 1.712 m/s, meanwhile, the results showed that the four slots inflow played a significant role in improving the strength of the generated vortex and increasing its outflow velocity to 5.635 m/s with an enhancement of about 3.5 times of one slot inflow.