Applied Solar Energy最新文献

The primary challenge in renewable energy production is the unpredictable nature of renewable sources, leading to inconsistent electricity generation. This variability causes deviations in power supply frequency and voltage due to imbalances between load demand and power generation. This study focuses on regulating power flow in a solar-wind-based Hybrid Power Generating System (HPGS) to achieve a stable balance between energy generation and demand. A Fractional Order PID (FOPID) controller is employed to minimize power fluctuations by ensuring Maximum Power Point Tracking (MPPT) and efficient management of Superconducting Magnetic Energy Storage (SMES). The SMES utilizes a second-generation superconducting material with a high irreversibility field and critical current density, enhancing energy storage efficiency. Compared to a conventional PID controller, the FOPID controller offers greater stability, reduced oscillations and overshoot, and a shorter rise time. To validate its effectiveness, a comparative analysis between conventional PID and FOPID controllers is conducted. The results demonstrate that the proposed FOPID controller ensures precise MPPT, rapid SMES response, and stable power exchange between supply and demand, even during sudden load shifts and variations in power generation.

This study presents the geometric optimization of a CeO₂-based solar thermochemical reactor intended for hydrogen production, using temperature distribution analysis under concentrated solar power conditions. The investigation was carried out entirely through numerical modeling using the COMSOL Multiphysics software, assuming a concentrator input power of 2 kW. The reactor body was designed with a stainless-steel exterior, while aluminum oxide (Al₂O₃) was selected as the internal insulating layer. Cerium oxide (CeO₂) was employed as a porous reactive medium to facilitate a two-step redox thermochemical cycle. A three-dimensional cylindrical model of 1 mol CeO₂ was developed to evaluate the thermal performance under varying porosity levels (ε = 0.1–0.9) and different cylindrical geometries with equal volumes. The simulation results revealed that at a porosity of ε = 0.7, the desired endothermic operating temperature was distributed most uniformly within a CeO₂ volume of 50 mm diameter and 20 mm thickness. Based on the temperature field distributions and effective heat transfer conditions, the reactor’s geometrical parameters were optimized. The final design includes a cylindrical body with a 220 mm diameter and 140 mm length, a quartz window of 200 mm diameter and 6 mm thickness, a 20 mm cooling channel for water circulation, and an internal insulating layer of aluminum oxide (Al₂O₃) with a thickness of 100–120 mm. Furthermore, the dimensions of the light-receiving conical section were determined as 50 mm for the small diameter and 152 mm for the large diameter.

With the large-scale deployment of renewable energy, photovoltaic systems are installed worldwide, including in regions with humid continental climate. We present here the energy production of 2-axis tracking systems equipped with either monofacial or bifacial modules. We show that severe weather conditions, especially in winter, force the systems to operate in a degraded mode (i.e. 10° fixed tilt) that leads to yearly losses of ~4%. Other losses that include snow-induced losses lead to 12 and 9% additional losses for monofacial and bifacial systems, respectively. Bifacial modules are better suited than monofacial modules in the studied climate and system configuration, thanks to a higher sensitivity to albedo and higher ability to shed snow during winter, that both amplify the bifaciality gain during snowy months.

The article presents the results of studying the structural and optical characteristics of films based on a mixture and alloy of ZnO, Al₂O_3, and Dy₂O₃ with a weight concentration of the components ZnO—96%, Al₂O₃—2%, and Dy₂O₃—1%. The alloy has been obtained by melting a mechanical mixture at the focus of a solar furnace with a concentrator diameter of 2 m. The films have been deposited onto glass plates by the resistive method in a vacuum. X-ray phase analysis showed that the films obtained from the alloy have a higher degree of crystallization than coatings obtained from a mechanical mixture of oxides. Regardless of the method of preparing the film-forming material, the ZnO crystal lattice undergoes strong stretching due to the introduction of Al₂O₃ and Dy₂O_3. The lower value of the transmittance coefficient compared to the simulation results is explained by the presence of metallic Zn, i.e., the formation of a Zn + ZnO cermet film. As a result of annealing the film at 400°C, its transmittance increased due to a decrease in the concentration of Zn.

The limited number of identified gaseous, liquid, and solid hydrocarbons, which are the main types of primary energy resources used in Uzbekistan; technological and technical difficulties in extracting them from the subsoil and subsequent processing for transportation; insufficient capacity to ensure their storage and delivery for use in the daily and seasonal variability of the need for electric and thermal energy in various areas of the country, etc., indicate the significance of the risks to energy security and ensuring the sustainable development of the country. Renewable energy resources, such as hydraulic, solar, and wind energy are significant and their gradual large-scale use that has begun indicates their significant potential in ensuring energy security and sustainable development. This part of the paper shows the feasibility of using modern energy-efficient technologies for the use of various types of accumulation/generation of the above-mentioned variable types of renewable energy sources in Uzbekistan with the implementation of opportunities both in increasing the total generation volume and in creating highly maneuverable “peak” generating energy sources for various functional purposes in various energy hubs of the country.

Central Asia’s fossil fuel-based energy systems need to transition towards clean energy to ensure energy security and sustainability. According to Central Asian energy reports, the sector related greenhouse gas emissions contribute to more than 80% of the total emissions of the region. At the same time more than 80% of power generation is still fossil fuel based while other sectors (e.g. transport) are still almost exclusively consuming fossil fuels. As the country with the fastest growing energy demand of the region, Uzbekistan aims to reach a 25% of renewable energy in power generation and to develop substantial capacities to produce green hydrogen by 2030. Further, the nationwide electricity consumption is expected to increase by more than 60% by 2030, which poses a significant challenge to the energy sector development. This work critically assesses the Uzbek Renewable Energy Development Strategy for 2030. It reviews the government’s current energy strategy to transform its power system, considering renewable energy and green hydrogen deployment. The work provides a modeling approach to identify the cost-efficient pathways of the Uzbek power sector using the Open Energy Modeling Framework (OEMOF). Preliminary results suggest that the Uzbek Governments renewable electricity strategy can be achieved at reasonable prices and already lower overall power costs. However, further optimizations find that much higher renewable energy shares are also possible at competitive costs under the same framework conditions.

One of the major challenges associated with solar photovoltaic (PV) power harnessing is the intermittent nature of its output. The situation worsens in partial shading as it leads to greater mismatch losses and reduced efficiency of PV modules. Consequently, this work proposes two novel algorithms designed to overcome the impacts of various patterns and shading levels over PV panels. One algorithm is designed on a puzzle-based reconfiguration (PBR) scheme that suggests the physical reconfiguration of PV modules in an array. Governed by mathematical relations, PBR effectively distributes the impact of shading as a function of reconfiguration of modules within the array. Comparative analysis of the results of PBR has been carried out with existing alternative configurations. Numerous performance parameters such as global maximum power, fill factor, and mismatch losses have been evaluated for different shading patterns. It is found that proposed PBR algorithm results in greater values of maximum power and fill factor with lowest mismatch losses among all configurations for any level and pattern of shading. Similarly, inspired by the flower pollination (FP) technique, a second algorithm is proposed for enhanced tracking speed with reduced oscillations under various levels of shading. The tracking speed of proposed FP algorithm is found to be higher than most preferred PSO approach and better results are obtained with the increase in shading level.

A composite material of cordierite composition based on the oxides MgO, Al₂O₃, and SiO₂ with a concentration of components, was obtained in a solar furnace, wt %: MgO—15.3–19.2, Al₂O₃—34.34–24.34, SiO₂ —50.59–56.45. It has been established that cordierite films deposited on the surface of glass and silicon wafers are characterized by high mechanical strength and adhesion, are transparent in the sensitivity range of solar cells, and can be used as an anti-reflection coating.

Biogas technologies play a main role in renewable energy; however, traditional biogas plants often fail to fully exploit the potential of raw materials, focusing solely on energy production. To enhance the efficiency of such systems, the development of hybrid biogas systems, which combine various technological processes, equipment, and energy sources, appears to be a promising approach. This study presents a review of modern engineering solutions in hybrid biogas systems based on patent analysis. A search and analysis of patent literature was conducted, covering the integration of anaerobic digestion with additional biomass treatment methods, biogas purification techniques, and combinations with other renewable energy sources (solar, wind, hydrogen, etc.). The key findings indicate that hybridization of biogas technologies significantly improves the performance and flexibility of biogas plants. Specifically, two-stage digestion increases biogas yield by 15–30%, CO₂ methanation (power-to-methane) raises CH₄ content up to 98%, and combined purification methods (membrane and adsorption) reduce methane losses to less than 1%. Furthermore, the integration of biogas plants with solar or wind energy systems reduces electricity production costs by 20–40%, while also ensuring more stable and predictable generation. The obtained data confirm that hybrid biogas systems enable the comprehensive utilization of organic waste while simultaneously generating energy and valuable by-products (biofertilizers, CO₂ for industrial needs, etc.). The patent analysis, encompassing developments from various countries, highlights a strong global interest in hybrid biogas technologies. Many of the patents are already transitioning from prototype stages to practical implementation, confirming the high potential of hybrid biogas systems for the future of energy. The identified approaches and solutions can be practically applied to modernize existing biogas facilities and develop new, more efficient bioenergy complexes, paving the way for further industry advancement and the realization of clean energy through rational waste management.