Novel Algorithm for Improving Tracking Accuracy of Open-Loop Mobile Sun-Tracking System via Different Timing Control SchemeRead the full article
International Journal of Photoenergy publishes original research and review articles focused on all areas of photoenergy, including photochemistry and solar energy utilization.
Chief Editor, Giulia Grancini, is based at the University of Pavia, Italy. Her current research work aims at solving the stability and toxicity issues of developing multi-dimensional hybrid interfaces as lego-bricks for a new efficient, stable, and environmentally-friendly solar technology.
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Technoeconomic Analysis and Optimization of Hybrid Solar-Wind-Hydrodiesel Renewable Energy Systems Using Two Dispatch Strategies
Sustainable generation is impacted by the adoption of renewable energy, the growth of energy markets, and economic strategies. This paper offers a sustainable strategy and a technoeconomic analysis of off-grid hybrid energy systems (HES) in remote islands of Iran, including Lavan, Larak, and Failaka, utilizing PV module, wind turbine, and hydrokinetic turbines. Hourly wind speed, solar irradiation, and hydrovelocity have been implemented under load following (LF) and cycle charging (CC) dispatch strategies in order to ascertain the most appropriate systems. Lavan Island achieves the winning HES with a CC dispatch strategy, which consists of 3 hydroelectric turbines, 1 wind turbine, 349 kW of solar power, 150 kW of generator power, 316 kWh of batteries, and 287 kW of the converter. This ideal HES, which generates a consistent generation profile and reasonable net present cost (NPC) and cost of energy (COE) of M0.160$ and $0.013 kWh, respectively, can be practically attained in these areas. LF-controlled optimal solutions use less fuel than CC-based ones, leading to a higher share of renewable energy. Compared to Larak and Lavan, the CC- and LF-controlled options on Failaka Island generate cleaner electricity with emissions that are 57% and 44% lower. Regarding the ability to recoup the project’s initial investment costs, long-term energy production would be more financially viable than short-term. Short-term projects with higher financial uncertainty due to the salvage cost should use the CC method.
Dibenzo[b,f][1,5]Diazocines/ZnO Organic/Inorganic Hybrid Photoanodes for Efficient Photo Electrochemical Water Splitting
In this study, we propose dibenzo[b,f][1,5]diazocine/ZnO organic/inorganic hybrid photoanode for application in the photoelectrochemical water splitting. The electrode consisting of inorganic ZnO nanorod (ZnO NR) array structures and organic diazocine derivative film with or without platinum nanoparticle (Pt NP) cocatalyst was examined. The morphology characterization was performed by FESEM. UV-vis absorbance spectra showed enhanced absorbance in the visible light spectrum for the hybrid sample. Photoluminescence analysis of a hybrid sample showed a significant decrease in charge recombination and enhanced charge separation. Photoelectrochemical measurements revealed an increase in current density for the organic/inorganic hybrid photoanode reaching 1.256 mA/cm2 at 1.23 V vs. RHE which is almost two times higher than bare ZnO NR arrays (0.716 mA/cm2 at 1.23 V vs. RHE). The addition of the Pt NP cocatalyst further enhanced the photocurrent density up to 1.636 mA/cm2. Therefore, proposed organic/inorganic hybrid photoelectrode is a promising candidate for the efficient solar water splitting.
Design and Implementation of a New Fast and Efficient MPPT Controller under Different Solar Irradiance Conditions
The power-voltage (P-V) characteristic curve of solar photovoltaic (PV) systems operating in partial shading conditions (PSC) is nonlinear and has multiple local maximum peak power (LMPP) points, rendering many of the maximum power point tracking (MPPT) algorithms ineffective at locating global maximum peak power (GMPP) points. This work proposes a novel slime mould algorithm- (SMA-) based MPPT controller to utilise maximum peak power (MPP) from solar PV systems during uniform irradiance conditions (UC) and nonuniform irradiance conditions (NUC). On the basis of the MPP they tracked, tracking time, and power efficiency, MPPT controller performance is assessed through MATLAB simulations and implemented experimentally with dSPACE MicroLabBox under various irradiance conditions. The effective performance of the proposed controller is validated and demonstrated in comparison to existing popular MPPT controllers.
Phytosynthesis of TiO2 Nanoparticles Using E. crassipes Leaf Extracts, Their Photocatalytic Evaluation and Microbicide Effect
In the present research work, the photocatalytic and microbicidal activities of titanium nanoparticles (TiO2 NPs) were evaluated. TiO2 NPs were obtained through the phytosynthesis process, using Eichhornia crassipes leaf extract. In order to determine whether particle size improves photocatalytic and microbicidal activities, the pH of the photosynthesized was modified to 12, 7, and 4. The TiO2 NPs modified were characterized by UV-Vis spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), and high-resolution transmission electron microscopy (HR-TEM) to reveal the crystalline and morphological nature of the phytosynthesized TiO2 NPs. UV-Vis analysis revealed that the wavelength for the TiO2 NPs was 327 nm, while FT-IR confirmed the presence of TiO2 NPs at peaks located between 536 and 532 cm-1. Finally, HR-TEM analysis showed that all nanoparticles had a TiO2 composition and a particle size ranging from 25 to 35 nm. For the photocatalytic and microbicidal tests, three concentrations of nanoparticles were used (100, 50, and 10 mg/L), and the results showed that TiO2 nanoparticles at a concentration of 10 mg·L-1 demonstrated excellent photocatalytic activity in photodegrading phenol [10 mg·L-1] up to 98.7%, while their microbicidal activity was more effective in contact with S. aureus than with E. coli, using a TiO2 NPs concentration of 100 mg·L-1.
Analysis of the Refrigeration Performance of the Refrigerated Warehouse with Ice Thermal Energy Storage Driven Directly by Variable Photovoltaic Capacity
An independent solar photovoltaic (PV) refrigerated warehouse system with ice thermal energy storage is constructed in this paper. In this system, the vapour compression refrigeration cycle is directly driven by a PV array, and the frequency of the compressor varies with the solar radiation intensity. The refrigeration performance and the matching characteristics of the system driven by different PV capacities are studied. The results show that the intensity of solar radiation required for the compressor to work at the same frequency decreases by approximately 7.8% when the ratio of PV capacity to compressor-rated power increases by 10%, and the time required for the temperature in the refrigerated warehouse to drop from ambient temperature to 0°C is reduced by 32 min on average. The energy efficiency ratio of the vapour compression refrigeration subsystem and the coefficient of performance (COP) of the refrigerated warehouse system increase with the ratio of PV capacity to compressor-rated power α. When α increases from 1 to 1.3, the growth rate of the COP is very slow. For the PV direct-drive refrigerated warehouse system with a compressor-rated power of 4.4 kW, the suitable ratio of PV capacity to compressor-rated power α is about 1.3. When the refrigerated warehouse system is driven directly by a 5.4 kW PV array, the overall COP is approximately 0.19. In the cycle mode of refrigeration and cold energy storage during the day and cold energy release at night, the stored cold energy can still meet the refrigeration required by the load for 48 hours after eight days of continuous operation. According to the current market price of cold storage, during the service life of the system, the income per unit volume of cold storage is about 2.2 times the investment.
Harmonic Analysis of Large Grid-Connected PV Systems in Distribution Networks: A Saudi Case Study
The increasing penetration of grid-connected PV rooftops at the distribution level still entails significant technical challenges affecting seriously the power quality indices such as harmonics and voltage fluctuations. Owing to the intermittent nature of renewable resources, the changing incident energy from renewables can generate considerable amounts of harmonics. Moreover, power electronic devices and nonlinear loads that are used frequently in the industry may exaggerate the harmonic distortions as well. Accordingly, utilizing suitable filtration techniques for harmonic reduction is crucial. In order to evaluate the impacts of grid-connected PVs in modern grids, a case study on power quality and voltage profile is conducted with a large grid-connected PV microgrid of 9570 kW, feeding a large hospital project in Saudi Arabia as an initial phase of implementing this project in the future. For eliminating the possible increase in harmonic distortion, a single-tuned filter is used to cope with the permissible limits according to the known IEEE standards. This filtering technique is chosen due to its advantages including the simplicity, suitability for significant integer harmonic orders, and low cost. For evaluation tests, a detailed simulation is developed by the ETAP program for the overall selected project as well as the aimed PV subsystem. Several simulation tests are conducted to investigate the harmonic distortion problem. The results show a significant reduction in the individual harmonic distortion (IHD) and the total harmonic distortion (THD) below 8% according to considered IEEE standards for LV networks. Both 6 and 12 pule inverters are considered. This is considered an important step in the realization of such large PV projects in the field.