Efficiency Of Power Generation System Research Articles

A novel proposal of using solar panels mounted on wind turbines for enhancement of power generation

To increase power generation, the next generation wind turbines are focusing more on hybrid systems. There is always a demanding need for more efficient wind power generation systems. In view of the improvements in the known types of turbines now available in the prior art, the present work proposes a novel hybrid wind and solar turbine construction wherein the same can be utilized for generating additional electrical power. A practical and feasible combination of wind turbine and solar panels has been designed. In this proposed novel arrangement, solar panels are secured to the surface of nacelle heli-hoist to supplement the power generation of a wind turbine.

Design Of A Hybrid Power Generation System in Cipatujah Tasikmalya Regency

The escalating daily demand for electricity, propelled by technological advancements and the pervasive use of electronic devices, accentuates the imperative for a dependable and sustainable power generation system. Renewable energy sources emerge as a viable solution to address the electricity needs in Indonesia, particularly in remote areas where access to the main grid is challenging. Tasikmalaya Regency, situated in West Java Province and defined by its geographical coordinates between 7°02' 29" - 7°49' 08" South Latitude and 107°54' 10" - 108°25' 52" East Longitude, presents a promising setting for the implementation of such sustainable energy solutions. The coastal area of Tasikmalaya, specifically Cipatujah Subdistrict, exhibits substantial renewable energy potential, including wind, solar radiation, and ocean waves. This research endeavors to design an efficient hybrid power generation system in Cipatujah Subdistrict using HomerPro software. The methodology involves crafting various models to determine the most economically efficient generation strategy. The study utilizes electricity consumption data sourced from the Karangnunggal Tasikmalaya Substation, situated in the southern coastal region of Tasikmalaya, particularly in Cipatujah Subdistrict, with a daily consumption of 20.6917 MW. By addressing the specific energy needs of the region, the research aims to make a positive contribution to the development of renewable energy and, concurrently, serve as a guiding framework for similar system designs in locations sharing comparable characteristics. This multifaceted approach underscores the significance of tailoring sustainable energy solutions to the unique requirements of diverse regions, fostering a broader transition towards a reliable and environmentally conscious energy future.

Implementation Joule Thief Buck-Boost Converter in A Neodymium Wind Power Plant

Wind power generation is gaining popularity as an environmentally friendly renewable energy source. However, the output voltage of a wind generator usually varies according to the wind speed, requiring a power converter to produce a stable DC voltage. The author of this research aims to implement a Joule Thief Buck-Boost Converter on a neodymium wind power generation system. Joule Thief is a DC-DC converter that has the ability to convert a low input voltage into a higher output voltage, and can maintain a relatively stable output voltage despite changes in the input voltage. In this study, a Joule Thief buck-boost converter is used to regulate the output DC voltage of the neodymium wind generator to remain stable despite the changing wind speed. System testing is done by measuring the output voltage of the neodymium wind power plant. The test results show that the Joule Thief Buck-Boost Converter can maintain the output DC voltage at a stable value of 14V at input voltages above 3V, so the implementation of this converter in neodymium wind power plants is proven effective in producing a stable DC voltage. This research is expected to contribute to the development of a more efficient and reliable wind power generation system.

Analysis of the thermodynamic performance of the SOFC-GT system integrated solar energy based on reverse Brayton cycle

Efficient power generation systems are an essential way to reduce carbon emissions. To avoid the complex effects of high-pressure conditions on the solid oxide fuel cell (SOFC) and gas turbine (GT) hybrid systems, while further improving energy efficiency. A SOFC-GT hybrid system based on the reverse Brayton cycle (RBC) is proposed, in which the SOFC operates at near atmospheric pressure conditions and GT expands below atmospheric pressure. Solar energy is integrated to further enhance system performance. Rigorous assessments of the novel system and the pressurized system are conducted utilizing energy, exergy and economic analysis. The sensitivity analysis of environmental parameters on the novel system's performance is performed. The results show that the novel system generates power and efficiency better than the conventional system when the GT compression ratio is 3 and 6, respectively. The power generation and exergy efficiency of the novel system at the design point is 60.47 % and 58.57 %, respectively. The largest exergy destruction occurred in the SOFC. The lowest exergy efficient components are the parabolic dish collector (PDC) and heat exchanger 2. The novel system is more cost-effective due to the higher lifetime of the SOFC, with the levelized cost of energy (LCOE) is 0.1418 $/kWh.

ML Assisted Foot Step Power Generation using Piezoelectric Sensors

In our rapidly evolving world, the escalating demand for energy coupled with the finite nature of traditional resources underscores the imperative for sustainable, pollution-free, and inexhaustible energy solutions. This paper introduces a pioneering approach to harnessing the kinetic energy expended during human locomotion through the innovative use of piezoelectric sensors. Leveraging the piezoelectric effect, these sensors efficiently convert mechanical energy generated by footstep pressure into electrical energy, thereby mitigating wastage and addressing the increasing energy needs. Our model advocates for the deployment of an extensive sensor network along footpaths, complemented by an RFID-based mobile charging system for enhanced convenience and functionality. Moreover, we introduce an innovative method integrating Machine Learning (ML) techniques to enhance power generation efficiency through intelligent modulation of piezoelectric element resistance. Additionally, we leverage ML algorithms to enhance the requisite daily footstep count necessary to fulfill the energy demands of specific areas. This proactive approach ensures optimal deployment of footstep power generation devices based on actual foot traffic patterns. Our research underscores the significance of this technology in the context of urban energy sustainability, particularly in densely populated regions like China and India, where foot traffic is abundant. By harnessing mechanical energy and leveraging advanced ML algorithms, our approach promises to revolutionize energy harvesting paradigms, paving the way for greener and more efficient power generation systems

Design and analysis of solitary AC–AC converter using reduced components for efficient power generation system

Considering different applications that require varied power and voltage conversion levels between AC grids and AC loads, AC–AC power conversion between AC grids has become an inevitable technology of energy management systems. An isolated converter for performing AC-to-AC transmission is proposed with minimal components for reduced losses and enhanced system efficiency. Single-phase direct buck-boost AC to AC converter with minimum components constituted with two dual IGBT control units (IGBT 1–IGBT 4), inductor (Lf), and capacitor (Cf) is proposed in this work. The MATLAB/Simulink platform is used to provide in-depth analysis of the circuit and components along with the design guidelines, and simulation outcomes of this proposed model. The voltage gains of G = 2.13, power factor of 0.97, and overall efficiency of 98% are achieved in the proposed system with minimum components of 4 switches, 2 conductors, and 1 capacitor and inductor respectively. The obtained results are compared with existing technology to evaluate the proposed system.

Effect of operating regimes on the heat transfer and buoyancy characteristics of supercritical CO2 natural circulation loop - A numerical study

At present, 82% of global energy is generated by fossil fuels which produce substantial emissions and have a significant impact on the environment. Heat transfer devices play a vital role in enhancing the efficiency of power generation systems and mitigating environmental impact. Among various heat transfer devices, natural circulation loops (NCLs) assume significance due to their simplicity and safety. In the present study, numerical investigations were conducted on three-dimensional rectangular circular cross-section supercritical CO2-based NCL across three distinct operating regimes. These regions include the average temperature of NCL maintained near the widom line (near pseudo-critical region), away from the widom line (higher buoyancy region) and very far away from the widom line (deeply supercritical region). The results indicate that in all regions, there is an increase in both the mass flow rate and heat transfer rate as pressure increases. At a pressure of 14 MPa, the maximum heat transfer rate across all regions is observed. Although the higher buoyancy region exhibits a superior heat transfer rate, the near pseudo-critical region demonstrates efficient heat transfer capabilities. For example, at 11 MPa, the temperature difference in the higher buoyancy region exceeds that in the near pseudo-critical region by 73%. However, the reduction in heat transfer rate in the near pseudo-critical region is only 37% compared to the higher buoyancy regions. For low-temperature applications, the near pseudo-critical region effectively transfers heat. However, in high-temperature applications, the sink temperature should be kept in the liquid-like region to maximize system buoyancy.

Efficient water recovery and power generation system based on air-cooled fuel cell with semi-closed cathode circulation mode

Air-cooled proton exchange membrane hydrogen fuel cell with on-line hydrogen production by hydrolysis has potential for portable applications due to its high volumetric power density and self-humidification. However, plenty of reserve water significantly reduces the power density of fuel cell system. Moreover, water recovery from fuel cell tail gas is difficult, because the tail gas humidity is very low due to excess cathode air as coolant. In this work, the dead-ended anode and semi-closed cathode proton exchange membrane fuel cell is proposed to achieve efficient water recovery and energy conversion via semi-closed cathode circulation mode. In this mode, cathode O2-poor tail gas is recycled as coolant instead of fresh air, which helps to enlarge the tail gas humidity by reducing the stoichiometric ratio of cathode to anode gas. The system lumped model with detailed component description is developed for optimization. >96% water production can be recycled under atmosphere temperature. The demand of fresh air is greatly reduced from 56 to 2 times of the consumption. Besides, the multi-objective optimization between water recovery and electrochemical performance shows high-efficiency water recovery of 94.70% and high energy conversion efficiency of 54.82%.

An optimization of efficient combined cycle power generation system for fusion power reactor

Fusion power plants can meet the energy demands of the world. The high thermal performance of a power generation system is still a challenge and one of the developing trends with a fusion reactor due to the high outlet temperature. A combined cycle system has been optimized to work at high outlet temperature and pressure of fusion power reactor with thermal power of 2500 MWth and its input parameter has been optimized along with impact of partial load to achieve high thermal performance very first time. The combined cycle based on the concept of two stages of expansion in the closed-Brayton-cycle and two reheaters in the Rankine cycle named Schematic-IV with the higher thermal performance of 58.19% as compared to Schematic-I, II and III has been proposed for a fusion power reactor. The increase in more than one expansion stage and reheat stage is not economical because it increased the thermal performance by about half of performance as compared to one. The effect of isentropic efficiency of compressor and heat rate have been investigated to validate the thermodynamic model and calculations. The optimized thermal performance of the combined cycle is 58.19% at a feed water mass flow rate of 592 kgs−1 and steam outlet temperature of 277 °C in the combined cycle. The heat rate decreased and thermal performance increased with the mass flow rate verifying that the thermodynamic model is correct. The thermodynamic analysis of the combined cycle-based nuclear reactor provides insights for better system thermal performance and reveals the effect of key parameters on the system performance.

High efficiency energy supply in residential sector using Fuel Cells

Increasing the overall efficiency of power generation systems has become a priority of research in the field of energy. In this sense, a conventional thermal power plant is able to convert around 33% of the energy contained in the primary fuel into electricity. The rest of the unused energy corresponds to energy dissipated as heat. By contrast, the overall efficiency of polygeneration systems is within 80-90% of fuel utilization. This combined production of heat-cold and electricity can be applied in the residential, industrial and service sectors. Considering the increase in energy efficiency that cogeneration involves, this paper presents an analysis of the possibilities of PEM fuel cells for cogeneration applications. To do this, a set of experimental measurements on a real fuel cell (PEM HP600) has been developed, in order to identify its electrical and thermal aspects, for different loading rates.

Efficient coal-based power generation via optimized supercritical water gasification with chemical recuperation

Supercritical water gasification (SCWG) is promising as a clean coal technology and is an emerging topic of interest in sustainable energy. Here, we introduce a clean and efficient power generation system that optimizes SCWG of coal through chemical recuperation. Central to our approach is the innovative utilization of both exhaust and a portion of the syngas as dual heat sources for gasification, simultaneously producing the requisite supercritical water. This chemical recuperation strategy effectively enhances the transformation of coal chemical energy into syngas. The introduced system achieves power generation and exergy efficiencies of 56.64 and 55.30%, respectively, outperforming those of a baseline system by 8.43 and 8.23%, respectively. This gain is primarily attributed to the irreversible losses in the gasification, air separation, and heat-exchange processes of the introduced system, which were reduced by 8.75, 2.47, and 4.17%, respectively, compared with the corresponding values of the baseline system. In order to elucidate and validate the reduced irreversible losses in the introduced system compared with those in the baseline system, we incorporated the energy utilization diagram methodology into our analysis. In summary, the introduced system represents a pivotal advancement in clean and efficient coal-based power generation and underscores the need for continuous innovation in this sector.

Energy, exergy and economic analysis for a combined cooling heat and power system: A case study for a university campus

Efficient power generation systems are required because of the rapid increase in demand for energy in industry, commerce, and residence. Systems that produce power and heat can have higher efficiency. In this work, a Combined Cooling Heat and Power (CCHP) system with a gas turbine is used to produce electric power for chillers and hot water for a university campus. The current energy plant for the university is described, showing the annual cost for each sub-system, and the cooling and heating demands. Five gas turbines are analyzed and used with a heat exchanger to produce hot water in the CCHP system. A thermodynamic model has been developed based on the parameters given by gas turbine manufacturers for the energy, exergy, and economic analysis. The thermodynamic and exergy calculations are compared with literature to verify the results. The difference between the company data and the thermodynamic model is 6.9% for turbine outlet temperature, and 0.3% for thermal efficiency. The average exergetic efficiency of the proposed energy plant is 45%. Siemens – 5.4 MW has the lowest payback and the highest ROI with 2.54 and 7.48%, respectively. The annual fuel cost for the Solar – Taurus 60 is US$1.2 million.

A State-of-the-Art Review on Optimization Methods and Techniques for Economic Load Dispatch with Photovoltaic Systems: Progress, Challenges, and Recommendations

Fossil fuel is considered to be the primary power generation source. As this source is not that eco- and environmentally friendly, researchers are constantly searching for an alternative source for power generation. Renewable energy has drawn much attention in this regard in recent times. For solving economic load dispatch issues, numerous operational constraints must be considered. Due to the restructuring of the power sector, there is competition between different power systems organizations. Increasing fossil fuel costs drive power-producing utilities to adopt a cost-effective technique for dispatching actual power output. Due to the presence of nonlinearity and non-convexity in the fuel of cost function of generators, the economic load dispatch is often considered a complex optimization problem. Many researchers have been optimizing fuel costs to solve the economic power dispatch problem. This paper offers a critical analysis of ELD that takes into account both traditional and non-traditional energy sources. The review covers a variety of algorithms, including hybrid algorithms for integrating renewable energy sources (RES). The paper also focuses on several restricted optimization techniques and contemporary algorithms including PSO, Jaya, GWO, SMO, TLBO, Rao, MRao-2, and MFO to reduce the fuel cost of generation units using large-scale solar PV. Moreover, this paper provides a comprehensive overview of the current state of economic load dispatch and provides valuable insights for electricity researchers and practitioners. It also discusses future technologies and next steps in the field of ELD, emphasizing the need for more environmentally friendly and cost-effective power generation and distribution solutions. Overall, the paper demonstrates the benefits of renewable energy sources as well as optimization techniques for creating a more sustainable and efficient power generation system.

Bilayer Cell Model and System Design of Highly Efficient Protonic Ceramic Fuel Cells

A highly efficient power generation system was designed by minimizing leakage current in protonic ceramic fuel cells (PCFCs) using bilayer electrolytes. The best electrolyte designs are achieved by optimizing the cell efficiency based on the transport properties of electrolyte materials assuming hydrogen as fuel. In parallel, the effect of the electrodes on the overall cell performance was also considered. Additionally, a PCFC system was modeled using the designed cells. Two PCFC systems were investigated. One based on hydrogen as a fuel, and another based on methane as fuel. It was found that a bilayer electrolyte consisting of BaZr0.8Y0.2O3−δ (BZY) with a thin layer of lanthanum tungstate (La28-xW4+xO54+3x/2v2-3x/2) is the most effective at reducing leakage current at 600°C. For this cell, a system efficiency of 69% (LHV, DC) and 65% (LHV, AC) were obtained under the cell voltage of 0.93 V, with a leakage current ratio of less than 1%, and fuel utilization of 95% when using hydrogen as fuel. On the other hand, when methane was used as fuel, the efficiency increased up to 78% (LHV, DC) and 74% (LHV, AC).

Utilization of methane from municipal solid waste landfills

Here, we analyzed the utilization efficiency of methane (CH<sub>4</sub>) gas from landfill sites associated with its power generation potential in different systems; in addition, we analyzed the reduction in the amount of CH<sub>4</sub> emitted from landfills of untreated waste, proposed an effective method for site selection, and investigated the environmental issues caused by landfilling solid waste. Furthermore, we evaluated the geographical and chemical characteristics, iteration variables of landfill operations, application of CH<sub>4</sub>, efficiencies of energy-converting systems, and reduction in the CO<sub>2</sub> emissions from other energy sources, with the landfill gas (LFG) being considered as the fuel. For efficient and quality extraction of CH<sub>4</sub> from LFG, we investigated the ideal landfill conditions (e.g., construction, geometry, weather, temperature, moisture, pH, and biodegradable matter) and hydrogeological parameters that influence the generation of LFG and landfill leachate. The first order decay equation was used to predict the CH<sub>4</sub> generation from a single bulk municipal solid waste stream for various characteristic interims of geography and CH<sub>4</sub> generation capacity and potential. More CH<sub>4</sub> is generated in the conventional clean air act condition than wet and arid conditions. Based on the analysis, we suggest efficient and economical power generation systems for using the CH<sub>4</sub> emissions from landfills.

Research on the performance characteristics of an oil-free scroll expander that is applied to a micro-scale compressed air energy storage system

The oil-free scroll expander, which is the power component of the micro-scale compressed air energy storage (CAES) system, exhibits a satisfactory application prospect. The expander's performance directly influences the efficiency of the expansion power generation system. To enhance the work efficiency of the power generation system, we built a thermodynamic model that facilitates the oil-free scroll expansion mechanism by considering heat transfer and leakage; furthermore, for the micro-scale CAES, we constructed an experiment bench that utilizes air as the working fluid. Based on computational fluid dynamics (CFD), we conducted a three-dimensional unsteady numerical simulation of the fluid flow that occurs in the working chamber of the scroll expander. We observed that the suction pressure loss that occurs during the suction process, which is initiated by the scroll expander, leads to inlet pressure drop, and we noted that the suction pressure directly influences the work efficiency of the power generation system. When the setup is subjected to rotational speeds of 1200–3200 r/min, the difference between the theoretical and measured values of volumetric flow decreases from 0.0226 to 0.000527 m3/min. The pressure, velocity, and temperature distribution of the fluid that exists in the working chamber of the expander are not uniform, and the mass exchange that occurs between adjacent working chambers considerably impacts the distribution of velocity and temperature. As gas flows from the back-pressure chamber to the outlet pipe, most of it flows through the non-deforming domain before flowing into the outlet pipe. The fluid flow in the deforming domain is highly complicated, and even secondary flow can occur.

NaNO3-KNO3-KCl/K2CO3 with the elevated working temperature for CSP application: Phase diagram calculation and machine learning

Mixed nitrates with relative low melting point have widely been used as thermal storage medium in the concentrated solar power stations. However, their maximum working temperatures aren’t high enough to integrate with more efficient power generation systems such as the supercritical CO2 cycle. In the present work, mixed nitrates with elevated working temperature were obtained by adding KCl/K2CO3. With the help of FactSage software and back-propagation (BP) algorithm combined with genetic algorithm (GA), the eutectic compositions and melting points of NaNO3-KNO3-KCl and NaNO3-KNO3-K2CO3 were predicted, and the validity of BP algorithm combined with GA was verified. Based on DSC and TG curves, the melting points of the as-prepared NaNO3-KNO3-KCl and NaNO3-KNO3-K2CO3 are 206.12 °C and 207.24 °C, respectively, which are in agreement with predicted values. Moreover, their decomposition temperatures were increased to more than 640 °C. In addition, the specific heat capacity of both mixed molten salts was measured, and it also was calculated by using FactSage software. This work provides two new ternary molten salts based on nitrates with higher working temperature and develops the prediction method on phase diagram calculation and machine learning.

Concept design, parameter analysis, and thermodynamic evaluation of a novel integrated gasification chemical-looping combustion combined cycle power generation system

Integrated gasification chemical-looping combustion (IGCLC) is a potential combustion technology with innate CO2 separation for solid fuels. Coupling this technology with coal-fired power plants is expected to greatly alleviate the high efficiency penalty induced by CO2 capture. This study proposes an innovative system called integrated gasification CLC combined cycle (IGCLCCC) that highly integrates a gasification system, a CLC system, a combined cycle, an ultra-supercritical steam cycle, and a CO2 capture system. In the proposed system, the oxygen-depleted stream from air reactor and flue gas from fuel reactor enter the combined cycle and ultra-supercritical steam cycle, respectively, for power generation. The energy and mass balances of the proposed system are determined by process simulation. The relationship between the performance of subsystems and system efficiency is studied by parameter analysis. Results indicate that the net efficiency penalty (0.3 percentage points) of the proposed system is 4.3 to 13.2 percentage points less than those of the conventional CO2 capture power plants, and the power consumption of specific CO2 capture is minimized to 8.3 kWeh/t. Besides, its net efficiency is as high as 45.0%, which is comparable to that of the natural gas combined cycle power plant with a 90% CO2 capture rate. This work provides a new sight into the design of the low-carbon and efficient power generation system.

Integration of wind turbine with biomass-fueled SOFC to provide hydrogen-rich fuel: Economic and CO2 emission reduction assessment

Addressing the energy crisis and global warming issues would entail urgent development of efficient and environmentally-benign power generation systems to mitigate the future clean energy policies. The biomass-driven SOFC systems are considered in this regard as pioneer technologies to supply clean power, particularly for decentralized applications. However, enough biomass availability and supply is a main challenge to run these systems. In current research to reduce biomass consumption, the biomass-driven SOFC is hybridized with wind turbines to produce pure hydrogen via a PEM electrolyzer. Produced hydrogen is added to the anode of SOFC to enrich the hydrogen content of the synthesis gas fuel. Feasibility assessment of proposed hybrid SOFC/wind turbine structure is examined considering first and second laws. Then, comprehensive economic and environmental appraisals are considered to inspect trade-offs between increased costs (associated with wind turbine and electrolyzer) and increased power as well as decreased CO2 emission. Finally to determine the optimal conditions for proposed system operation, triple-objective optimization via genetic algorithm is implemented. Obtained results have revealed exergy efficiency enhancement by 7.3% and CO2 emission reduction by 13.0 %, via incorporation of wind turbine. These technical and environmental performance enhancements are achieved at the expense of around 6.4 % increase in unit electricity cost, due to the increment of capital expenditures associated with the wind turbine and water electrolyzer. From parametric analysis, it is found that, the proposed framework yields lower electricity price and CO2 emission under higher cell temperatures and lower fuel utilization factors.

Day-Ahead Operation Analysis of Wind and Solar Power Generation Coupled with Hydrogen Energy Storage System Based on Adaptive Simulated Annealing Particle Swarm Algorithm

As the low-carbon economy continues to evolve, the energy structure adjustment of using renewable energies to replace fossil fuel energies has become an inevitable trend. To increase the ratio of renewable energies in the electric power system and improve the economic efficiency of power generation systems based on renewables with hydrogen production, in this paper, an operation optimization model of a wind–solar hybrid hydrogen energy storage system is established based on electrochemical energy storage and hydrogen energy storage technology. The adaptive simulated annealing particle swarm algorithm is used to obtain the solution, and the results are compared with the standard particle swarm algorithm. The results show that the day-ahead operation scheme solved by the improved algorithm can save about 28% of the system operating cost throughout the day. The analytical results of the calculation example revealed that the established model had fully considered the actual operational features of devices in the system and could reduce the waste of wind and solar energy by adjusting the electricity purchased from the power grid and the charge and discharge powers of the storage batteries under the mechanism of time-of-use electricity price. The optimization of the day-ahead scheduling of the system achieved the minimization of daily system operation costs while ensuring that the hydrogen-producing power could meet the hydrogen demand.