Electrical Power Output Research Articles

Theoretic and experimental performance of a grid-connected photovoltaic system: Multiple prediction model of efficiency and annual energy generation

In this article, the performance of a 3.36 kWp grid-connected photovoltaic system (GCPVS) under warm and subhumid weather conditions and the development of a predictive mathematical model is presented. Climate data of the 2021 year were used to evaluate energy generation, different types of performance, and efficiency. The average annual yield, corrected yield, array, and final yields were 6.45 h/day, 6.18 h/day, 5.16 h/day, and 4.97 h/day, respectively. The overall annual mean capacity factor and efficiency ratios were 20.73% and 77.22%, correspondingly. Experimental data were analyzed and correlated by multivariate linear regression (MLR) prediction and simulation to validate models. The MLR analysis showed that the efficiency is highly dependent on the temperature of the PV modules and that climatic parameters significantly affect the efficiency and output electric power. The prediction models for PV module efficiency, system efficiency, and direct current energy exhibit an uncertainty of ±1.04%, ±0.57%, and ±35.38 kWh, one-to-one. The monthly generation was compared with results obtained by Energy3D simulation-free software, showing an absolute error of ±2.33 kWh. This information can be used as a methodological tool for predicting efficiency and power generation in direct current.

ENERGY & EXERGY ANALYSIS OF A PV PANEL WITH PASSIVE COOLING MECHANISM

A photovoltaic (PV) array is grately responsive to changes in temperature; contrarily, reduction in temperature is the major factor that subsidize to an raise in the electrical efficiency and output power of a PV system. To optimize the production of energy by PV panels and reduce their temperature, a photovoltaic (PV) cooling system is basically used. Nonetheless, more insolation is generally associated with higher temperatures, which is ambiguous for photovoltaic (PV) panels because they rely on that irradiance to create power. These extreme temperature rises have a devastating effect on how skillfully photovoltaic (PV) panels transforms energy. A solar photovoltaic (PV) system can opearte more accurately with an adequate cooling system on its surface. In this paper, a passive cooling model for the PV panel has been devloped which cools down the PV panel by employing dry grass and water at the back surface. A correlation has been made with a non-cooled panel. Two PV panels are simultaneously tested. Electrical output properties of both the PV panels have been recorded and energy and exergy analysis for the system has been presented to have a more detailed understanding of the cooling effect on PV panel performance. The cooled panel has an increase in efficiency by 47%. Along with the electrical efficiency, the thermal efficiency has also been presented in this paper for performance evaluation in the form of overall efficiency.

Metal foam recuperators on micro gas turbines: Multi-objective optimisation of efficiency, power and weight

Small size and high efficiency of micro gas turbines require a higher surface-to-volume ratio of recuperators. Conventional recuperators can achieve a range of 250–3600 m2/m3. Advances in materials and manufacturing, such as metal foams, can increase significantly the exchange surface and improve compactness ranging approximately from 500 to over 10,000 m2/m3, due to their exceptional micro geometry. The main advantage is that the increase of surface area does not impact the cost of the heat exchanger as much as conventional recuperators due to their easy manufacturing. This work addresses the optimisation of the recuperator using multiple objectives satisfying efficiency, power output and weight criteria, offering a holistic approach that takes into account the entire system rather than individual components or channels. A model is developed to represent the performance of a compact heat exchanger in micro gas turbines. The recuperator is an annular heat exchanger with involute profile filled with porous media in a counterflow arrangement on the hot and cold sides. The model allows the evaluation of the effect of the recuperator geometry features on the electrical efficiency, power output and weight savings in a micro gas turbine. Existing models for the global heat transfer coefficient, effective thermal conductivity, surface area and pressure drop of porous media are selected and implemented. The design variables of multi-objective are the pore density, porosity and number of channels, whilst the objectives are the overall electrical efficiency, power output and recuperator weight. The problem is solved using the Non-Dominated Sorting Genetic Algorithm (NSGA-II) to determine an approximation of the Pareto front, whilst the accuracy of the approximation is assessed against the solution obtained by an exhaustive search. The comparison shows that NSGA-II outperforms an exhaustive search by at least 90 % in terms of computational efficiency. These results allow the quantification of the impact of metal foam technology on performance metrics of the recuperator as well as the entire system. This quantitative analysis provides valuable insights into the behaviour of metal foam recuperators in micro gas turbines. An optimal design with 30 % efficiency and 28 kW power output appears in pore densities of approximately 10 and 20 pores per inch (PPI) for the air and gas side respectively, and a porosity of 85 %, which leads to a state-of-the-art recuperator weight of 48 kg. The efficiency improvement over the industry standard is 15 %, with only a 2.5 % reduction in power output.

Energy, exergy, economic, and life cycle environmental analysis of a novel biogas-fueled solid oxide fuel cell hybrid power generation system assisted with solar thermal energy storage unit

Biogas production and its derived hydrogen production technology have broad application prospects. In this paper, an integrated biogas power generation system with solid oxide fuel cells is proposed, which mainly consists of four units: a solar thermal energy storage unit, a biogas production and hydrogen generation unit, a SOFC-MGT unit, and a waste heat utilization unit. The presented system is first studied using energy, exergy, economic, and life cycle environmental analyses and the survey results are contrasted with those of renewable energy systems discussed in the references. Besides, a parametric study is conducted to explore the effect of thermodynamic parameters of solar irradiance, ambient temperature, work fluid temperature, reforming temperature, inlet H2O/CH4 ratio of the reformer, and the current density of SOFC. Results indicate that the proposed system's energy efficiency, exergy efficiency, electric power output and exergy destruction are 43.29%, 37.4%, 414.16 kW (net power generation is 351.43 kW) and 1434.59 kW, respectivily. Moreover, the system's levelized cost of electricity and carbon emission factor are $0.076/kWh and 335.6gCO2eq/kWh, having good economic and environmental benefits simultaneously. The parametric study shows that PTSC can be designed shorter with more solar irradiance and high ambient temperature. Besides, the increase of inlet H2O/CH4 ratio and reforming temperature make the system's energy efficiency fall by 2.5% and 20%. For every 300 A/m2 increase in the current density of SOFC, the system efficiency rises by 1.01%.

Calcium copper titanate incorporated polydimethylsiloxane flexible composite film-based triboelectric nanogenerator for energy harvesting and self-powered sensing applications

Triboelectric energy harvesters offer an efficient way to convert mechanical energy harvested by everyday human body actions into electrical energy. Triboelectric nanogenerators (TENGs) are an attractive solution for power supply concerns in the development of portable electronic gadgets and self-powered sensor applications. Herein, a dielectric calcium copper titanate (CaCu3Ti4O12 (CCTO)) ceramic material was synthesized by a solid-state reaction process. The synthesized particles were embedded in polydimethylsiloxane (PDMS) polymer to form a CCTO/PDMS flexible composite film (FCF)-based TENG, called a CCTO FCF-TENG, which is light-weight, simple, and suitable for use. The dielectric properties, surface charge density, and electrical conductivity of the FCF were greatly improved by the addition of the CCTO particles into the PDMS, resulting in excellent electrical output performance of the corresponding CCTO FCF-TENG. The CCTO FCF-TENG device was constructed with the CCTO/PDMS FCF, which functioned vertically against a cellulose paper to optimize a high and stable electrical output. Furthermore, the filler concentration and film thickness optimization was studied more to achieve the highest output power of the CCTO FCF-TENG. The optimized CCTO FCF-TENG exhibited the highest electrical output voltage, current, charge density, and power density of ∼250 V, ∼6.5 μA, ∼70 μC/m2, and ∼3.15 W/m2, respectively. The mechanical stability and durability of the CCTO FCF-TENG were systematically analyzed. The practical and real-time applications of the packed CCTO FCF-TENG were systematically investigated under various harsh environmental conditions. Finally, the packed CCTO FCF-TENG successfully powered several low-power portable electronics and was also used as a self-powered sensor to sense biomechanical actions in everyday human body activities.

A Mathematical Model for Dynamic Electric Vehicles: Analysis and Optimization

In this article, we introduce a flexible and reliable technique to simulate and optimize the characteristics of a Dynamic Electrical Vehicle (DEV). The DEV model is a discrete event-based modeling technique used in electrical vehicle research to improve the effectiveness and performance of various electrical vehicles (EVs) components. Here, the DEVS model is applied to EV research in several ways, including battery management optimization, evaluation of power train design and control strategy, and driver behavior analysis. The essential power train elements, including the battery, motor, generator, internal combustion engine, and power electronics are included in the mathematical model for the dynamic electric vehicle. The model is derived using the conservation of energy principle. The model includes mathematical equations for the electrical power output, battery charge level, motor torque, motor power output, generator power output, internal combustion engine torque, mechanical power delivered to the generator, and the efficiencies of the power electronics, motor, generator, and engine. The model is examined by using a numerical method called the Runge–Kutta Method of order 4 for dynamic electric vehicle’s performance under various driving states for maximum effectiveness and performance. It is revealed that the DEV model provides a systematic method to simulate and optimize the behavior of complex EV systems.

A nanofluid-based hybrid photovoltaic-thermal -thermoelectric generator system for combined heat and power applications

This study investigates the use of nanofluid-cooled Thermoelectric Generators (TEGs) integrated with a Photovoltaic (PV) panel to enhance the overall energy efficiency of the system. Three cooling fluids — Water (W), CuO/W single Nanofluid (NF), and CuO-Fe/W hybrid NF — are examined at various flow rates for cooling the PV panel. The research studies the PVT-TEG-NF system considering both normal and concentrated solar irradiation in a 3D parallelly-cooled heat sink setup and comparing its electrical and thermal performance, which has not been previously addressed in the literature. The results demonstrate that by utilizing CuO-Fe/W, the PV temperature at irradiation of 935 W/m2 in the summer can be maintained at 31.7 °C, which is 8.8 % and 13 % lower than those achieved by using CuO/W and water, respectively. For 0.08 m/s of CuO-Fe/W inlet velocity, the total output power PV-TEG is about 9.5 W, with a heat removal rate of ∼37.2 W. Additionally, by utilizing the CuO-Fe/W compared to water, the combined efficiency of the system (the ratio of electrical and thermal power output to solar input) increases from 66.7 % to 76.7 %. In the second part, the study introduces a new approach to maintain a steady PV efficiency while increasing solar concentration by adjusting the cooling fluid flow rate. By increasing solar concentration from 1.5 suns to 2.5 suns, the PV temperatures could be maintained at 44.5 °C and 51.5 °C using CuO-Fe/W and water with 0.12 m/s of inlet velocity, respectively. This made it possible to enhance the power output of the PV and TEGs by 65.9 % and 187 %, respectively, by using CuO-Fe/W as coolant, while the temperature of the panel could be maintained at a safe level.

Investigation on combining multi-effect distillation and double-effect absorption refrigeration cycle to recover exhaust heat of SOFC-GT system

This study introduces the double-effect absorption refrigeration cycle (D-ARC) and multi-effect distillation with thermal vapor compression unit (MED-TVC) technologies to recover exhaust heat from the SOFC-GT system. This scheme can efficiently utilize waste heat at various temperature levels while enabling large-capacity cooling and freshwater production. The supercritical CO2 Brayton cycle is employed to facilitate the reliable operation of D-ARC and MED-TVC within their preferred temperature zones while enhancing the power output of the entire system. The techno-economic-environmental evaluation, comparative analysis and sensitivity analysis are performed to explore the feasibility of its engineering implementation. The proposed system obtains thermal, exergic and electrical efficiencies of 78.56 %, 65.41 % and 65.77 % with the total cost rate being 18.53 $/h and freshwater production 829.30 ton/year under design conditions, respectively. Exergy analysis indicates that SOFC and afterburner exhibit the highest irreversibility with values of 21.60 kW and 26.02 kW among all the components. Comparative analysis reveals that the system has exceptional thermal efficiency while exhibiting competitive advantages in electrical and exergic efficiencies compared to similar systems. Sensitivity analysis demonstrates that the electrical efficiency and net power output stabilize at their respective maximum values within the SOFC inlet temperature range of 514.3℃-528.6℃. Moreover, it is a promising option by increasing SOFC operating pressure and GT isentropic efficiency to enhance system efficiency and reduce CO2 emission. This work contributes to the development and waste heat recovery of the SOFC-GT system and other prime power units with similar exhaust gas temperature levels.

The effects of design parameters on the dynamic performance, in-cylinder pressure and electrical power generation of a free piston linear engine

Operation of a free piston linear engine is modeled based on the combination of three mathematical models, including a piston dynamic model, a linear alternator model and a thermodynamic model. The simulated in-cylinder pressure, piston velocity, and electric power output are compared with the corresponding experimental results to validate the models mentioned above. The influences of the design parameters, including cylinder dimension ( Le), number of coil turns ( N), and air gap ( g) between the translator and stator, on the dynamic performance, in-cylinder pressure and electric power generation of the free piston linear engine are studied. The study results show that the reduction of Le has a benefit for improving the piston dynamic performance and output electric power, however it also reduced the cylinder pressure. The increase of number of coil turns N results in the reduction of the peak piston velocity, displacement, acceleration, and pressure in the cylinder, however, it increases the output electric power of the free piston linear engine. The peak piston velocity, displacement, acceleration, and pressure in the cylinder are considerably decreased when g is reduced. However, the reduction of g has a benefit to improve the output electric power of the free piston linear engine. The energy conversion efficiency can be maximized when g and Le are reduced, and N is increased.

Napelem hőterjedés vizsgálata elektromos paramétereinek a meghatározásához

Heat transfer processes in a photovoltaic (PV) silicon solar panel are simulated under standard circumstances. A model containing an intricate treatment of the incoming solar radiation, long-wave radiation, conduction, convection, and electrical power output is developed in mathematical form. To solve heat transfer problems, recent explicit numerical methods are utilized by our research group, which are efficient for different real-life problems, for example, simulating heat transfer in photovoltaic panels. Since very realistic results are obtained for the temperature of the silicon layer and the dependent electrical variables such as the power output, one can conclude that our model can adequately predict the electrical quantities.

Design and Development of a Biomimetic Solar Tree for Sustainable Cogeneration: An Energy and Exergy Assessment

Solar energy is becoming an increasingly popular and important source of renewable energy. Solar trees have emerged as a novel and innovative approach to harvesting solar energy. Solar trees are artificial structures that mimic the shape and function of trees, with branches or leaves that contain photovoltaic cells to convert sunlight into electricity. The solar tree generates both electrical and thermal energy from solar radiation. The present study tested the thermal (module temperature, heat loss coefficient), electrical (power output), and operating parameters of a solar tree at Universiti Malaysia Pahang, Pekan, Malaysia, on a typical sunny day. First-law analysis and second-law analysis were carried out to determine exergy losses during the photovoltaic conversion process of solar trees. The data obtained from the experiment is utilized to determine the energy and exergy efficiencies of the solar tree. The energy efficiency ranges from 16.8% to 8.3% throughout the day, displaying some variability. However, as for the exergy efficiency of the photovoltaic solar tree under consideration, it is observed to be lower, ranging from 16.1% to 6.6% for electricity generation. It is observed that the exergy losses increased with increasing module temperature and a drop in exergy efficiency.

Exploring cooling of PV panels based on metallic and nonmetallic nanofluids: An experimental study

An outdoor experimental study investigated the cooling of photovoltaic (PV) panels using nano-fluids containing metallic (calcium carbonate, CaCO3) and non-metallic (ferro-magnetite, Fe3O4) particles. The study compared the solar power output and efficiency of PV panels cooled by various nano-fluids, as well as uncooled and water-cooled systems, under laminar and turbulent flow conditions with flow rates ranging from 1000 to 7000 mL/min. Aluminum heat exchangers (460 mm in length, 10 mm in outer diameter, and 10 mm in thickness) were attached to the rear surface of each PV cell, enabling the analysis of cell temperature, thermal performance, and electrical performance. The use of CaCO3 and Fe3O4 nano-fluids notably reduced the average cell surface temperature compared to uncooled and water-cooled systems. Fe3O4 nano-fluid, in particular, excelled due to its high thermal conductivity, which resulted in an improved heat transfer coefficient and Nusselt number when compared to air and water cooling. The electrical performance, power output, and efficiency of the PV cells all improved when cooling systems were employed in contrast to the uncooled condition. Among the available cooling methods, Fe3O4 nano-fluid stood out for its superior results, thanks to its exceptional thermal conductivity.

A Comparative Experimental Performance Analysis for Fixed Solar PV Systems and Solar Tracker PV Systems in a Tropical Region

Solar photovoltaic (PV) systems promise a reliable future for renewable energy adoption, with the capability for mitigating greenhouse gas emissions and combating climate change while providing a sustainable energy solution to the planet. This study investigates the efficiency of solar tracking technology in tropical regions, focusing on Sri Lanka, which is an island located near the equator. In this study, a comparative performance analysis of a fixed-ground mounted solar PV system and a solar tracking PV system was conducted under identical system conditions and environmental conditions. The power output, operating temperature, short circuit current (Isc), open circuit voltage (Voc) data were collected continuously for 11 hours for both systems with 5-minute time intervals. The experimental results show a significant enhancement of the electrical power output of the solar tracking PV system compared to fixed-ground mounted solar PV systems. The average power output enhancement was 14.46% and the study also observed a 4.43% higher solar panel operating temperature in solar tracking PV systems. Results show that the single-axis solar tracking PV system consistently outperforms the fixed-ground mounted system, particularly in the morning and evening, due to its ability to maintain perpendicular sunlight incidence.

Constant Voltage Model of SCIG-Based Variable Speed Wind Power Plant for Load Flow Analysis

In recent years, the application of variable-speed wind power plants (WPPs) has become more and more popular and surpassed fixed-speed WPPs. This popularity is mainly because variable-speed WPPs are much more efficient in capturing or extracting wind energy than fixed-speed WPPs. Due to its relatively cheaper cost, the use of SCIG (Squirrel Cage Induction Generator)-based variable-speed WPP is currently increasing. This type of WPP is usually equipped with a power electronics converter to obtain a broader range of variable-speed operations. Modeling the power system components is undoubtedly necessary for performing the system analysis (including load flow analysis). This paper discusses the steady-state model of SCIG-based variable-speed WPP for load flow analysis of electric power distribution systems. The proposed model can be used for SCIG-based variable-speed WPP with voltage control operating mode. The model was developed based on formulas that calculate the turbine mechanical power input and the WPP electrical power output. This paper also presents a case study in which the proposed model is applied to a representative electric power distribution system.

Thermoelectric properties of armchair graphene nanoribbons with array characteristics.

The thermoelectric properties of armchair graphene nanoribbons (AGNRs) with array characteristics are investigated theoretically using the tight-binding model and Green's function technique. The AGNR structures with array characteristics are created by embedding a narrow boron nitride nanoribbon (BNNR) into a wider AGNR, resulting in two narrow AGNRs. This system is denoted as w-AGNR/n-BNNR, where 'w' and 'n' represent the widths of the wider AGNR and narrow BNNR, respectively. We elucidate the coupling effect between two narrow symmetrical AGNRs on the electronic structure of w-AGNR/i-BNNR. A notable discovery is that the power factor of the 15-AGNR/5-BNNR with the minimum width surpasses the quantum limitation of power factor for 1D ideal systems. The energy level degeneracy observed in the first subbands of w-AGNR/n-BNNR structures proves to be highly advantageous in enhancing the electrical power outputs of graphene nanoribbon devices.

Nanocomposite Electret Layer Improved Long-Term Stable Solid-Liquid Contact Triboelectric Nanogenerator for Water Wave Energy Harvesting.

With the continuous rise of environmental pollution and energy crisis, the global energy revolution is risen. Development of renewable blue energy based on the emerging promising triboelectric nanogenerators (TENG) has become an important direction of future energy development. The solid-liquid contact triboelectric nanogenerator (TENG) has the advantages of flexible structure, easy manufacture, and long-term stability, which makes it easier to integrate and achieve large-scale conversion of wave mechanical energy. However, the electric power output is still not large enough, which limits its practical applications. In this work, a nanocomposite electret layer enhanced solid-liquid contact triboelectric nanogenerator (E-TENG) is proposed for water wave energy harvesting, which can effectively improve the electric output and achieve real-time power supply of wireless sensing. Through introducing a nanocomposite electret layer into flexible multilayer solid-liquid contact TENG, higher power output is achieved. The E-TENG (active size of 50mm×49mm) shows desired output performance, a power density of 521mWm-2. The generated electric energy can drive wireless temperature sensing by transmitting wireless signals carrying detection information at the period of ˂5.5min. This research greatly improves the electric output and provides a solid basis for the industrialization of TENG in blue energy.

Performance Evaluation of Centrifugal Pump-As-Turbine For Micro Hydro Applications

The Philippines is entirely dependent on imported hydropower (HP) system parts, specifically the turbine and generator. The use of a centrifugal pump as a turbine is a good option for the HP system due to its low cost and wide availability in the market. The performance of the centrifugal pump-as-turbine was evaluated under the following conditions: (1) different head setting, (2) different configurations of the draft tube, and (3) a match with an AC generator. A 75x75mm end suction, non-self-priming centrifugal pump was used in this study. The head settings used were 0.28 kg/cm2 to 0.84 kg/cm2 (pressure gauge reading). A prony brake dynamometer was fabricated to measure the torque at the shaft of the pump-as-turbine. The configurations of the draft tube used include: (a) conical angles - 0°, 4°, and 6°, and (b) draft tube lengths – 0.4572 m, 0.9144 m, and 1.3716 m. A 900W AC generator was matched with the pump–as–turbine and tested at different pressure and load settings. Results showed that the centrifugal pump could operate in turbine mode without any mechanical modifications. The highest mechanical efficiency obtained was 83.60% and was attained at a pressure setting of 0.70 kg/cm2. The highest shaft power of 1.02 kW that was attained at 0.84 kg/cm2 pressure setting. Based on the results, in terms of shaft power, the best draft tube configuration has a conical angle of 4° and a length of 1.3716 m. Meanwhile, in terms of efficiency, the best draft tube configuration is 4° conical angle and 0.4572 m length. The generator speed of 4000 rpm was obtained at a pressure setting of 0.84 kg/cm2. On the other hand, a generator speed of 3800 rpm was obtained at a pressure setting of 0.63 kg/cm2. It could be observed that the maximum power (515 W) obtained during the actual run was way below the expected output (847 W). The system efficiencies as well as the electrical power output could improve if the belt slippage is reduced. It is recommended to conduct more testing to be able to determine the full potential of the pump-as-turbine.

Changes in The Electrical Output Power and Efficiency of A Photovoltaic Panel Cooled by A Hybrid Method

During the process of generating electrical energy from photovoltaic panels, high ambient temperatures and radiation tend to cause excessive heating of the photovoltaic panel, resulting in a decrease in its efficiency. In this experimental study, two cooling methods were employed. The first method involved active cooling using water, while the second method combined active cooling with passive cooling using an aluminum heat sink, all while using water as the cooling medium. The experiment involved the analysis of changes in electrical output power and efficiency from three identical 100 W monocrystalline photovoltaic panels, one of which served as the reference. The first panel was considered the reference panel. The second panel featured active cooling, with a liquid reservoir created on its rear surface to be filled with transformer oil. Copper pipes were placed at specific intervals within this liquid reservoir, and the rear surface was covered with a thin flat metal plate. The third panel was prepared for the hybrid method, featuring a liquid reservoir covered with a rectangular finned aluminum heat sink, distinct from the second panel. In both methods, transformer oil was used for electrical insulation and thermal conduction between the panel and the copper pipes at the rear. The copper pipes were connected to an automotive radiator and a pump to form a closed circuit. The water inside the radiator was cooled using a radiator fan and circulated by a pump. In the first method, active cooling was achieved by cooling through the radiator, while in the hybrid method, active cooling through the radiator was combined with passive cooling using the rectangular finned aluminum heat sink. In the experiment setup, temperature and liquid flow were measured using radiation, electrical sensors, and other measuring instruments. The data obtained from the measurements were used to compare the increases in electrical power and efficiency of the panels. The electrical power increase and efficiency were calculated as follows: in the hybrid method, it was found to be 4.7% and 0.84%, respectively, while in the active method, it was 2.94% and 0.52%, respectively. The energy consumed in the study was provided by wind energy

Controlling and Modelling a Grid Connected Photovoltaic System for Performance Investigation Purpose

The world restriction of fossil power sources reserves and its side effect on the environmental pollution have impelled strongly using the photovoltaic technology as alternative renewable energy sources. The essential problem is the difficulty of importing and installing solar panels without having a fully knowledge about its effectiveness in the climatic conditions of the university site. Hence, the motivation of this study is to investigate the operational efficiency of the PV system in the Iraqi environmental conditions by modelling, controlling, and simulating the system using MATLAB/Simulink program. The proposed model has been driven based on the principle mathematical equations that depict the behaviour of the PV solar system. The proposed model is designed to affect with the sunlight irradiance, ambient temperature, AC loss, DC loss, the temperature of the panels’ surfaces, and the efficiency of the used inverter. Preliminary results showed a strong correlation between sunlight irradiance and ambient temperature with the power generated by solar panels. Thus, these two parameters are chosen as the major inputs to the model. While, the electrical output power and the accumulative energy are set as the output of the simulated model. The study investigates the performance of the proposed model at the hottest day and coldest day throughout the year 2022. The results proved that the system generates more energy during the summer than in the winter due to the strength and a long period of the radiation falling on the ground during this season. Moreover, the investigation study evidenced that the system efficiency decreases as ambient temperatures increase. As the results, the cumulative energy during one day decreased by around 41.366% from the summer to winter. Finally, the authors recommend installing the suggested solar cell system in Iraq because its effectiveness was theoretically proved.

Self-powered ocean buoy using a disk-type triboelectric nanogenerator with a mechanical frequency regulator

Triboelectric nanogenerator (TENG) systems have been demonstrated to generate power with high density. However, the electrical output power obtained from wave energy harvesting using TENG systems is typically limited to several milliwatts. To address this limitation and support various ocean buoy systems, an efficient method to scale-up TENG systems is required. In this paper, we present a self-powered ocean buoy (SPOB) incorporating a disk-type, soft-contact, mechanical frequency regulator TENG (DSMFR-TENG). The mechanical frequency regulator (MFR) enables the conversion of low-frequency wave energy to high-speed mechanical rotation, facilitating high power generation with the disk-type TENG. The SPOB was tested in a wave tank, reaching a peak power output of 470 mW and an average power output of 130 mW after the MFR released the rotational energy. To further enhance the functionality of the buoy, the DSMFR-TENG and a microcontroller, temperature sensor, and acoustic transmitter were integrated with the SPOB. The acoustic transmitter successfully transmitted signals 7, 23, and 30 times over a one-minute period at wave frequencies of 0.33 Hz, 0.5 Hz, and 1 Hz, respectively, thereby demonstrating the power supply capability of the TENG system for ocean buoys.