Solar Energy Power Generation Research Articles

Dynamic characteristics and control method of the solar-coal energy complementary system

The solar-coal energy complementary technology is an effective way to use solar energy for power generation. In this work, a 330 MW coal-fired power generation unit, with an integrated solar field system, was studied to improve solar energy utilization efficiency and control performance. The dynamic mathematical model of the system was established using a lumped parameter method; the maximum relative error was found to be less than 5 %. Different coupling methods for the solar thermal system and coal-fired power unit were studied, and the dynamic characteristics of the unit under different solar radiation intensities were obtained. Finally, a coordinated control system was proposed based on the multiscale decomposition of load commands. The results show that the new coordinated control system showed more flexibility and less fluctuation of power during regulation. It has the best control effect, with the integral of the absolute value of the error criterion reaching 890.8 and 795 in step and slope experiments, respectively, and the integral of time multiplied by the squared error criterion reaching 4.172 × 105 and 3.043 × 105, respectively. This study successfully demonstrates the effective use of solar-coal energy complementary technology and provides an important reference for future work.

Model development and preliminary study of the concentrated-radiative cooling based thermoelectric generator

Photovoltaic (PV) cells, widely adopted in solar energy applications, achieve a maximum efficiency of only 30 % and remain inactive during nighttime. In contrast, solar-thermal power generation has surpassed 50 % efficiency. To address these limitations, we introduce the Solar- Radiative cooling -Thermoelectric system (Solar-RC-TE), integrating solar energy, radiative cooling (RC), and thermoelectric power generation. This system enhances energy density, reduces consumption, lowers costs, and minimizes environmental impact while enabling nighttime power generation. For the optimization of the Solar-RC-TE model to further improve power generation efficiency, we employ the comprehensive three-dimensional methodology of COMSOL, considering material properties, structural configurations, and environmental factors. Research findings reveal that a 710 mm × 710 mm radiative cooling film can generate 386.12 mV of voltage on the thermoelectric generator (TEG). Environmental factors, such as increased solar irradiance, lead to temperature elevation, affecting efficiency. Overheating and higher wind speeds also contribute to decreased TEG efficiency. Regarding materials, improving the thermoelectric figure of merit (ZT) and film emissivity positively impact power generation efficiency. Elevating the film emissivity from 0.7 to 0.89 significantly enhances performance by 1.2 %. These outcomes provide a tangible and practical solution for addressing energy crises and environmental concerns.

Enhanced Power Generation Using a Dual-Surface-Modified Hematite Photoanode in a Direct Glyphosate Photo Fuel Cell.

Given the current and escalating global energy and environmental concerns, this work explores an innovative approach to mitigate a widely employed commercial herbicide using a direct glyphosate (Gly) photocatalytic fuel cell (PFC). The device generates power continuously by converting solar radiation, degrading and mineralizing commercial glyphosate-based fuel, and reducing sodium persulfate at the cathode. Pristine and modified hematite photoanodes were coupled to Pt/C nanoparticles dispersed in a carbon paper (CP) support (Pt/C/CP) dark cathode by using an H-type cell. The Gly/persulfate PFC shows a remarkable current and power generation enhancement after dual-surface modification of pristine hematite with segregated Hf and FeNiOx cocatalysts. The optimized photoanode elevates maximum current density (Jmax) from 0.35 to 0.71 mA cm-2 and maximum power generation (Pmax) from 0.04 to 0.065 mW cm-2, representing 102.85 and 62.50% increase in Jmax and Pmax, respectively, as compared to pristine hematite. The system demonstrated stability over a studied period of 4 h; remarkably, the photodegradation of Gly proved substantial, achieving ∼98% degradation and ∼6% mineralization. Our findings may significantly contribute to reducing Gly's environmental impact in agribusiness since it may convert the pollutant into energy at zero bias. The proposed device offers a sustainable solution to counteract Gly pollution while concurrently harnessing solar energy for power generation.

Study on combined optimization technology of wind-solar-storage hybrid power generation based on electricity hydrogen complementarity

The wind-solar-storage hybrid power generation system is mainly composed of wind turbines, solar cell arrays, electrolytic cells, fuel cells, battery packs, intelligent controllers, multi-functional inverters, cables, supports and auxiliary parts to supply power to the load. The system utilizes wind and solar energy for power generation without an external power supply, and an energy storage module composed of an electrolytic cell, fuel cell, and battery is used to assist the power supply. In this paper, a fuel cell model, a wind power generation model and a solar power generation model are respectively constructed, and a small experimental platform was built to validate the model. The pulse width modulation (PWM) control method, combined with the auxiliary regulation of the system by the battery, reduces the impact of the volatility of wind power generation on the electrolytic cell and fuel cell, and makes the load current more stable under different working conditions. The simulation results show that the system has good compression resistance, fast response and good stability.

Implementing a Digital Twin-based fault detection and diagnosis approach for optimal operation and maintenance of urban distributed solar photovoltaics

Over the next decades, solar energy power generation is anticipated to gain popularity because of the current energy and climate problems and ultimately become a crucial part of urban infrastructure. Furthermore, in order to facilitate the rapid deployment of solar production in sustainable cities, solar technologies must be digitalized and smart. This will increase their reliability and ensure their optimal performance. This work fits into this perspective and focuses on the effectiveness of processing data using the Digital Twin (DT) framework as a state-of-art information technology for urban distributed solar PV systems. Accordingly, the present paper deals with the DT of five Building-added Photovoltaic (BAPV) systems installed at the solar village in Benguerir city, Morocco. The 3D models were generated in the Rhinoceros platform, the solar AC electrical production of each photovoltaic system is calculated by the ladybug-plugin-integrated statistical model, within the grasshopper environment. Additionally, data assessment and visualization are processed through Python. Then, a hybrid model-based and data-driven fault detection and diagnosis (FDD) approach is proposed to identify and isolate anomalies for decentralized solar PV systems at the urban scale using monitoring and inspection techniques, namely Remote Sensors (RS) and real-time solar production monitoring system. The application of the DT concept for complex dynamic systems has shown its effectiveness in ensuring optimal operating conditions for the energy systems by measuring the spatiotemporal energy performance of distributed solar PV systems at an urban scale, evolving with the changing environment, and identifying degradation based on anomalies occurrence; Only then when the physical models need to be amended. Therefore, the main goal behind this work is to advance knowledge regarding research on condition monitoring of solar systems in cities while considering issues related to anomalies like the degradation phenomenon in PV modules over time. The findings of this study have proved that the state of health and monitoring of PV systems could be successfully detected and efficiently monitored using the combination of real time monitoring and remote aerial sensing.

Study on structure design and control of concentrating germanium solar power system

In the solar energy application system, in order to improve the efficiency of solar cells and the utilization of light energy, the paper studies the solar tracking system with concentrating device and using germanium solar cells. This paper compares the differences between germanium cells and silicon cells in terms of photoelectric conversion efficiency and output characteristics, and demonstrates the superiority of germanium solar cells. Several common types of concen-trating devices such as Fresnel lenses, trough concentrators, tower concentrators and disc con-centrators were listed, and the disc concentrator was finally selected considering the concen-trating performance and cost. The paper also analyzes the solar operation law and the charac-teristics of various tracking devices, and on the basis of comprehensive analysis of the ad-vantages and disadvantages of various tracking devices, a hybrid tracking scheme is proposed. After completing the design of the system structure, the efficiency and cost of the traditional fixed solar system and the concentrated germanium solar power generation sunny system are compared and analyzed by SIMULINK modeling, and the results show that the solar energy utilization rate and power generation efficiency of the system designed in this paper are greatly improved, which verifies the effectiveness and economy of the system. The concentrating germanium solar power generation system not only adopts germanium cells with better photo-electric characteristics, but also adds a concentrating device and a sun tracking device, which greatly improves the efficiency of solar power generation. And the volume of the device is not large, which can realize the promotion of small home solar energy systems.

Technical Simulation for the Hydromagnetic Rotating Flow of Carreau Fluid with Arrhenius Energy and Entropy Generation Effects: Semi-Numerical Calculations

The present study aimed to investigate the influence of activation energy on the MHD Boundary layer of Carreau nanofluid using a semi-numerical/analytical technique. The governing formulated system of partial differential equations (PDEs) subject to appropriate boundary conditions is shortened to ordinary differential equations (ODEs) by convenient transformations. Generalized Differential Transform (GDTM) is used and compared with the Runge–Kutta Dahlberg method to find the results of the proposed system. GDTM is chosen to cure and overcome the highly non-linear differentiation parts in the present system of ODEs. Gradients of velocity, temperature, and concentration are computed graphically with different values of physical parameters. The solutions are offered in two cases, the first in the case of non-Newtonian fluid (We=0.2) and the other in the case of base fluid (We=0.2), which is concluded in the same figure. The accuracy of GDTM is tested with many existing published types of research and found to be excellent. It is worth-mentioned that the distribution of velocity growths at high values of power index law relation. This fluid model can be applied in solar energy power generation, ethylene glycol, nuclear reactions, etc.

Methanol steam reforming reactor with fractal tree-shaped structures for photovoltaic–thermochemical hybrid power generation

The photovoltaic–thermochemical (PVTC) hybrid system converts thermal energy dissipated by concentrating photovoltaic cells to gain in power generation via the endothermic methanol steam reforming (MSR) reaction. Conventional MSR reactors are challenged by undesirable performances in heat transfer and methanol conversion, impacting the performances of power generation and energy storage of PVTC systems. In this work, an innovative fractal tree-shaped structure is introduced into the flow channels configuration of an MSR reactor to enhance heat transfer performance and methanol conversion. The methanol conversion of the novel reactor is experimentally assessed, which is 12.1 percentage points (relative improvement of 26.5%) higher than that of conventional reactors with serpentine flow channels design. A 3-D multiphysics model of the MSR reactors coupling heat transfer, gas flow, and chemical reaction is developed to reveal the mechanism of methanol conversion improvement. The fractal tree-shaped structure can improve the net solar-electric efficiency of the photovoltaic–thermochemical hybrid system by 5.6–7.5% (up to 36.6%). The efficient solar energy power generation of the PVTC system with energy storage ratio ensures considerable dispatchability for hybrid solar power generation.

High resolution photovoltaic power generation potential assessments of rooftop in China

Rooftop photovoltaic system plays an important role in solar energy power generation especially in urban. In this paper, we present an assessment method for the PV power generation potential of rooftop in China. Using machine learning model processes the big data that consists of the gross domestic product, building footprint, road length and population, at a high geographic resolution of 10 km by 10 km. The result shows that the rooftop generation potential in China is 3.27×109 MWh annually, which is close to half of the total electricity generation of China mainland in 2020, and will contribute to 2.41×109 tons of CO2 emission reduction per year. The regional results are counted by provinces and cities, showing Shandong province is the one with highest potential of 0.275×109 MWh. On the whole, the western region covers a large area with sufficient solar radiation, while the eastern region has greater photovoltaic power generation potential because of its available roof resources. The development potential of first tier, new first tier and second tier cities is generally greater than that of third and fourth tier cities.

Influence mechanism of solder aging and thermal network model optimization of multi-chip IGBT modules

With the continuous increase in the scale of new energy grid-connected, high-power converter IGBT modules are widely used in wind, solar, and other new energy power generation systems. The safe and reliable operation of IGBT modules with parallel chips is becoming more and more important. In the multi-chip module, uneven solder aging will increase the thermal resistance of some chips, which will lead to an inaccurate estimation of the junction temperature of the multi-chip IGBT power module. To this end, this paper proposes to use the reconstructed thermal impedance matrix to modify the multi-chip thermal network model and estimate the junction temperature. By analyzing the nonlinear accelerated deterioration law between the aging degree of the solder layer and the self-thermal impedance and coupled thermal impedance of the IGBT module, the influence mechanism of different solder layer aging degrees inside the module on the thermal conduction radius and thermal diffusion angle is clarified. The thermal impedance matrix is reconstructed with the modified thermal diffusion angle, thus realizing the optimization of the thermal network model of the multi-chip IGBT module. The experimental results show that the junction temperature calculation results of the improved multi-chip IGBT module thermal network model are more in line with the finite element simulation than the traditional unimproved method, thus verifying the validity and accuracy of the model, and laying a solid foundation for the large-scale integrated multi-chip thermal analysis. Theoretical basis.

Solar photovoltaic program helps turn deserts green in China: Evidence from satellite monitoring

Solar energy is considered one of the key solutions to the growing demand for energy and to reducing greenhouse gas emissions. Thanks to the relatively low cost of land use for solar energy and high power generation potential, a large number of photovoltaic (PV) power stations have been established in desert areas around the world. Despite the contribution to easing the energy crisis and combating climate change, large-scale construction and operation of PV power stations can change the land cover and affect the environment. However, few studies have focused on these special land cover changes, especially vegetation cover changes, which hinders understanding the effects of the extensive development of solar energy. Here, we used Continuous Change Detection and Classification - Spectral Mixture Analysis (CCDC-SMA) based on Landsat images to monitor changes in vegetation abundance before and after the PV power stations deployment. To reduce the interference of PV shading on vegetation abundance estimation, we improved the vegetation (VG) fraction from SMA and developed the Photovoltaics-Adjusted Vegetation (PAVG) fraction for vegetation abundance measurements in PV power stations. Results show that PV power stations in China's 12 biggest deserts expanded from 0 to 102.56 km2 from 2011 to 2018, mainly distributed in the central part of north China. The desert vegetation in the deployment area of PV power stations presented a significant greening trend. Compared to 2010, the greening area reached 30.80 km2, accounting for 30% of the total area of PV power stations. Overall, the large-scale deployment of PV power stations has promoted desert greening, primarily due to government-led Photovoltaic Desert Control Projects and favorable climatic change. This study shows the great benefits of PV power stations in combating desertification and improving people's welfare, which bring sustainable economic, ecological and social prosperity in sandy ecosystems.

Selection Criteria for the Implementation of a Power Generation Cycle Using Carbon Dioxide as Working Fluid and Solar Thermal Energy

The increase in energy demand and the high levels of pollution are high impact factors nowadays. Therefore, there is an interest in using energy like sources of waste heat and renewable energy. This paper describes a method for selecting solar-powered power cycles that use carbon dioxide as a working fluid. The method considers factors such as ambient conditions, reliability, capital investment, and maintenance costs. An analytic hierarchy process is used to determine the weighting factors for each criterion and the option weights for each cycle. The results show that the most important aspects of solar energy power generation are the ambient conditions and reliability. The significance of this research is that it provides some fundamental criteria for selecting and implementing power generating cycles that use CO2 as a working fluid and solar thermal energy.

Multi-criteria modeling and assessment of PV system performance in different climate areas of Iran

Although the use of solar energy for power generation has grown significantly in recent years, due to its location-oriented nature, choosing the best location for the development of a PV system is of great importance. This paper evaluates the performance of a PV system in five different cities of Iran with diverse climatic conditions in order to investigate the effect of weather and climatic conditions on the efficiency and performance of PV panels. Numerous studies on this topic have been conducted in order to find the greatest and most cost-effective geographic location for employing PV systems in various industries. Using a mathematical model, the effect of temperature and radiation on PV system performance has been investigated. Then, by defining various performance indicators, using the SMART method, the studied cities are ranked in a multi-criteria decision-making process. Finally, in order to evaluate the model, its outputs have been validated using System Advisor Model software. According to the research outputs, the city of Yazd has provided the best performance, followed by Isfahan, Bandar Abbas, Tabriz and Tehran. The data show that the amount of energy produced per year and average annual calculated efficiency in the city of Yazd, as the best city, is equal to 8,184.59 (kWh) and 18.24%, respectively. This led to a capacity factor of 23.57 and performance ratio of 0.887 for this city.

Optimization of wind solar and battery hybrid renewable system using backtrack search algorithm

<p>Penetration of renewable sources to the grid is always a problem for electrical engineers, apart from reliability and efficiency, cost optimization is also a big concern among them. Wind, solar and battery hybrid combinations (WSB-HPS) are also very common among hybrid systems, but this WSBHPS combines wind and solar energy power generation reduces the charge and discharge time of the battery. Therefore, this system improves the reliability of the power supply by fully utilizing the wind and solar power generation and improves the charging and discharging state of the battery and hence reduces the whole cost as the investment in battery is reduced. backtrack search algorithm (BSA) is the highly efficient and powerful algorithm to solve combinatorial optimization problems. In this paper an attempt is made to optimize the hybrid combination using BSA in the matrix laboratory (MATLAB) environment and comparable study is made using HOMER. A complete optimised data is generated for a particular area in Manipur and reduced cost is suggested.</p>

CFD Simulations for Performance Enhancement of a Solar Chimney Power Plant (SCPP) and Techno-Economic Feasibility for a 5 MW SCPP in an Indian Context

The use of solar energy for power generation using the innovative solar chimney concept has been explored by many researchers mostly with the help of analytical models as well as CFD simulations while experimental studies for a pilot and bench scale facilities have been carried out. The efficiencies of these chimneys, however, are less than 1% (~0.07% for 50 kW pilot plant similar to Manzanares plant in Spain). In the present study, an effort has been made to make modifications in the chimney design to improve the efficiency of the chimney in terms of power generation. CFD simulations have been carried out for this modified design and the efficiency is seen to improve to 0.12% for a 50 kW chimney. Furthermore, a techno-economic feasibility analysis has been carried out for a conventional 5 MW solar power plant which can be installed on the western part of India, which receives good solar irradiation throughout the year. Two cases with and without government subsidies have been considered. It is observed that a high rate of return (~20.4%) is obtained for a selling price of electricity of Rs 5 per kWh with government subsidy, while a rate of return of ~19% is obtained for Rs 10 per kWh without government subsidy.

Energy-Exergy Analysis of Solarized Triple Combined Cycle Having Intercooling, Reheating and Waste Heat Utilization

Heliostat-based solar thermal power system consisting of a combination of the Brayton cycle, Rankine cycle, and organic Rankine cycle is a potential option for harnessing solar energy for power generation. Among different options for improving the performance of solarized triple combined cycle the option of introducing intercooling and reheating in the gas turbine cycle and utilizing the waste heat for augmenting the power output needs investigation. Present study considers a solarized triple combined cycle with intercooling and reheating in gas turbines while using the heat rejected in intercooling in heat recovery vapour generator and heat recovery steam generator separately in two different arrangements. A comparison of two distinct cycle arrangements has been carried out based on Ist law and IInd law of thermodynamics with the help of thermodynamic parameters. Results show that triple combined cycle having intercooling heat used in heat recovery vapour generator offers maximum energy efficiency of 63.54% at 8 CPR & 300K ambient temperature and maximum exergetic efficiency of 38.37% at 14 CPR & 300 K. While the use of intercooling heat in heat recovery steam generator offers maximum energy and exergetic efficiency of 64.15% and 39.72% respectively at 16 CPR & 300 K ambient temperature.

Solar energy forecasting using intelligent techniques: A step towards sustainable power generating system

The rapid advancements in the technology, increase in comfort levels, movement of population to urban areas, depletion of fossil fuels and increasing greenhouse gas emissions have invigorated the use of renewable energy resources for power generation in the last few years. The major renewable energy resources which have potential to fulfill the requirements includes solar energy, wind energy, small hydro and biomass etc. Among these major resources, solar energy-based technology is considered as one of the fastest growing technology because of its various advantages and ubiquitous availability of the resources. However, there are certain challenges in the utilization of solar energy for power generation because of various uncertainties in the atmosphere. As a result, the power generated from solar based power plants is fluctuating in nature which is not desirable. Therefore, the utilities are adopting the smart grid approach which has ability to integrate the solar power plants efficiently and the solar energy forecasting is one of the essential tools for this new model. In this paper, AI based techniques are utilized to forecast solar energy using high quality measured solar irradiance data. The forecasting accuracy of the developed models is evaluated based on statistical indices such as absolute relative error and mean absolute percentage error. The results obtained from the developed models are compared to observe the forecasting ability and performance with the high-quality measured data and found accurate.

Operation strategy and dynamic performance study of integrated solar combined-cycle system

Integrated solar combined-cycle (ISCC) system has better thermal performance than the original gas steam combined-cycle system and a lower initial investment than stand-alone solar thermal plants. However, due to the uncertainty of meteorological conditions, the operation condition of the ISCC system changes continuously. In this study, a dynamic model of the ISCC system is built, and the operation strategies of two ISCC systems with and without the heat storage system are proposed. Accordingly, the dynamic performances of these two ISCC systems on a typical day are compared and analyzed, and the response characteristics of main operation parameters, such as main steam parameters and solar energy power generation, concerning direct normal irradiance (DNI) are obtained. The results show that the stability and security of the ISCC system with a heat storage system are superior to those without the heat storage system during the operation. To verify whether the operation strategy of the ISCC system with heat storage system is universally adaptable under different meteorological conditions, the dynamic performances of the ISCC system are further studied on a good-weather day with a strong DNI and a bad-weather day with weak DNI, respectively.

Open‐circuit fault diagnosis method for three‐level neutral point clamped inverter based on instantaneous frequency of phase current

Because the three-level neutral point clamped (NPC) inverter has the advantages of a large output capacity and high output voltage, it is widely used in wind energy and solar energy power generation. Unfortunately, the three-level NPC inverter often suffers from open-circuit faults, which leads to system security problems and great economic losses. To guarantee the secure operation of the three-level NPC inverter, an open-circuit fault diagnosis method for a three-level NPC inverter based on the instantaneous frequency (IF) of the phase current is proposed here. First, different open-circuit fault signals of the NPC inverter are analysed. Then, the IF of the phase current is used to obtain the fault diagnosis variables. Simultaneously, the Hilbert transform (HT) is used to estimate the IF of the phase current, which carries the information of open-circuit faults. Meanwhile, the average value of the normalised current is provided to locate faulty switches. Finally, by combining the diagnostic variables with the identification threshold, the detection and localisation of open-circuit faults in the NPC three-level inverter are determined. Compared to other fault diagnosis methods, the proposed method is more stable and makes it easier to diagnose open-circuit faults. The correctness and robustness of the method are verified by simulation results.

Novel method to operation conditions identification of high-order power converters

IntroductionIntermittent solar energy causes different operational modes of power converters including continuous current modes (CCMs) and discontinuous current modes (DCMs), which need appropriate control strategies and parameters assignment to ensure the functionality of the overall solar energy power generation system. Hence, it is important to identify suitable operation modes for a high-order converter system. However, for a high-order power converter (HOPC), traditional time-domain analysis method and bifurcation analysis are inapplicable, since this requires comprehensive analysis and sophisticated control design. ObjectivesTo improve reliability and reduce mathematical complexity, this paper focuses on the operation mode derivation of HOPCs to well identify its boundary conditions and provide industry standards for converter applications. MethodsWith complex operation modes, 3-Z-network converter is analysed as a typical example and its derivations of boundary conditions are elaborated. In detail, the equilibrium points and boundary conditions of each operation modes are first derived; then with the guidance of boundary conditions, unexpected operation modes can be avoided by parameters reassignment. ResultsSimulations and experimentation on the newly established system prototype are conducted to validate the effectiveness of the proposed approach. It demonstrates that the theoretical and experimental boundary conditions are in good agreement. ConclusionThis paper provides equilibrium points and boundary conditions, and obtains deeper insights into the behaviors of the 3-Z-network converter. The derivations of four operation modes and the boundary condition of each mode has been conducted and provided for the large-signal averaged model of the converter, which provides guidance for engineers to adjust the system parameters so as to realize required operation modes. Simulation and experimentation have verified the accuracy and effectiveness of the proposed identified operation boundaries.