scholarly journals Performance Modeling of the Weather Impact on a Utility-Scale PV Power Plant in a Tropical Region

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ajith Gopi ◽  
K. Sudhakar ◽  
Ngui Wai Keng ◽  
Ananthu R. Krishnan ◽  
S. Shanmuga Priya

Solar photovoltaics and the associated applications are now considered the most promising technologies for a sustainable future. The performance of the PV power plants is not studied in detail with respect to the influence of various weather parameters like rain, relative humidity, and atmospheric pressure on energy generation. The objective of this research work is to analyze and model the weather impact of a utility-scale PV power plant in a tropical region. The methodology involves the detailed analysis of the PV plant performance for various weather seasons and modeling the energy generation based on important weather parameters obtained from a Solar Radiation Resource Assessment (SRRA) station installed at the PV power plant location itself. Solar generation and its performance are affected during the rainy seasons, and it turns out to be a typical phenomenon in the humid tropical region. A regression model of solar generation for all the weather seasons is generated based on different weather parameters.

Author(s):  
Shane E. Powers ◽  
William C. Wood

With the renewed interest in the construction of coal-fired power plants in the United States, there has also been an increased interest in the methodology used to calculate/determine the overall performance of a coal fired power plant. This methodology is detailed in the ASME PTC 46 (1996) Code, which provides an excellent framework for determining the power output and heat rate of coal fired power plants. Unfortunately, the power industry has been slow to adopt this methodology, in part because of the lack of some details in the Code regarding the planning needed to design a performance test program for the determination of coal fired power plant performance. This paper will expand on the ASME PTC 46 (1996) Code by discussing key concepts that need to be addressed when planning an overall plant performance test of a coal fired power plant. The most difficult aspect of calculating coal fired power plant performance is integrating the calculation of boiler performance with the calculation of turbine cycle performance and other balance of plant aspects. If proper planning of the performance test is not performed, the integration of boiler and turbine data will result in a test result that does not accurately reflect the true performance of the overall plant. This planning must start very early in the development of the test program, and be implemented in all stages of the test program design. This paper will address the necessary planning of the test program, including: • Determination of Actual Plant Performance. • Selection of a Test Goal. • Development of the Basic Correction Algorithm. • Designing a Plant Model. • Development of Correction Curves. • Operation of the Power Plant during the Test. All nomenclature in this paper utilizes the ASME PTC 46 definitions for the calculation and correction of plant performance.


Author(s):  
Komandur S. Sunder Raj

The objectives of an effective power plant performance monitoring program are several-fold. They include: (a) assessing the overall condition of the plant through use of parameters such as output and heat rate (b) monitoring the health of individual components such as the steam generator, turbine-generator, feedwater heaters, moisture separators/reheaters (nuclear), condenser, cooling towers, pumps, etc. (c) using the results of the program to diagnose the causes for deviations in performance (d) quantifying the performance losses (e) taking timely and cost-effective corrective actions (f) using feedback techniques and incorporating lessons learned to institute preventive actions and, (g) optimizing performance. For the plant owner, the ultimate goals are improved plant availability and reliability and reduced cost of generation. The ability to succeed depends upon a number of factors such as cost, commitment, resources, performance monitoring tools, instrumentation, training, etc. Using a case study, this paper discusses diagnostic techniques that might aid power plants in improving their performance, reliability and availability. These techniques include performance parameters, supporting/refuting matrices, logic trees and decision trees for the overall plant as well as for individual components.


Author(s):  
Selorme Agbleze ◽  
Fernando V. Lima ◽  
Natarianto Indrawan ◽  
Rupendranath Panday ◽  
Paolo Pezzini ◽  
...  

Abstract Due to the increased penetration of renewable power sources into the electric grid, the current number of existing coal-fired power plants shifting from baseload to load-following operations has also increased. This shift creates challenges especially for the power industry as coal-fired power plants were not designed for ramping situations, leading to added stress on major components of these plants. This stress causes the system to degrade over time and eventually develop faults. As boilers are still the primary component that fails and causes forced outages, accurate characterization of faults and fractures of boilers is now becoming increasingly critical to reduce plant downtime and extend the plant life during cycling operations. This work focuses on modeling sections of a subcritical coal-fired power plant and proposes algorithms for fault detection in MATLAB/Simulink. The developed model simulates the process dynamics including steam and feedwater flow regulating valves, drum-boiler, and heat rate on the regulation of pressure, drum level and production of saturated steam. The model also simulates the dynamics of superheaters for increasing the energy content of steam, and a spray section for regulating the temperature of steam upstream of the high-pressure turbine to allow for power output adjustment within a given valve operating range. Furthermore, an extension to a leak detection framework proposed by co-authors in previous work is explored. The new framework includes a modification to the threshold analysis portion of the previous work. The extended framework is then applied to a subcritical coal-fired power plant model for leak detection. In particular, this framework analyzes mismatches or deviations in expected plant dynamics with an identified transfer function model. The mismatch is flagged after it exceeds a threshold. The developed algorithm thus aids in rapid detection of faults to reduce impeded plant performance. The results of this work will support real plant operations by providing an accurate characterization of faults in the operation of coal-fired power plants.


Author(s):  
Aleksandr E. Kishalov ◽  
Almir A. Zinnatullin

Every year, the share of decentralized energy generation in Russia is increasing. The following factors contribute to the development of this scenario: increased wear of the country’s energy system equipment, energy shortages, and lack of centralized energy supply in a number of regions and constantly rising tariffs. One of the methods of decentralized energy generation is the use of low-capacity power plants based on the Rankine cycle with an organic working fluid. The operation of such plants requires cooling and condensation of the working fluid by transferring its heat to the environment. This study discusses the design of such a power plant and the heat removal system to a cold source. is the authors consider the design of a condenser which is a horizontal pipeline placed in the ground. Seasonal fluctuations of the soil temperatures affect the operation of the condenser. Thereby, to ensure the stable operation of the power plant, it is necessary to quantitatively assess the effect of the annual dynamics of the soil temperature state on cooling and condensation of the coolant. The study of the temperature fields of the soil, pipeline and working fluid, as well as the lengths required for cooling and condensation of the working fluid, was carried out in the ANSYS CFX software package for numerical hydrodynamic modeling. A homogeneous flow model was chosen to simulate the momentum and condensation of a vapor-liquid medium. Also, the calculations were conducted in a one-dimensional formulation using an engineering method. A methodology for modeling complex processes of heat transfer to the soil using numerical modeling has been developed and verified. 12 calculations were made; the distributions of the steam dryness and temperature in the simulated region depending on the time of the year were obtained. The functions of the total length of the pipeline, cooling and condensation lengths on the soil temperature are analyzed. It has been established that the harmonic change in the temperature of the soil set as the initial condition determines a similar change in the lengths required for cooling and condensation of the working fluid. Using this technique, it is possible to calculate pipelines of more complex shapes. The obtained temperature distributions in cross sections allow to establish the optimal distance between the axes of the pipes when designing a condenser in the form of a bundle of horizontal pipes or a bent pipeline.


Author(s):  
Ana R. Diaz

The tendency in the world energy demand seems clear: it can only grow. The energetic industry will satisfy this demand-despite all its dialectic about new technologies-at least medium term mostly with current fossil fuel technologies. In this picture from an engineer’s point of view, one of the primary criterions for mitigating the effects of increasing atmospheric concentration of CO2 is to restrict the CO2 fossil fuel emissions into the atmosphere. This paper is focused on the analysis of different CO2 capture technologies for power plants. Indeed, one of the most important goal to concentrate on is the CO2 capture energy requirements, as it dictates the net size of the power plant and, hence, the net cost of power generation with CO2 avoidance technologies. Here, the Author presents a critical review of different CO2 absorption capture technologies. These technologies have been widely analyzed in the literature under chemical and economic points of view, leaving their impact on the energy power plant performance in a second plan. Thus, the central question examined in this paper is the connection between abatement capability and its energetic requirements, which seriously decrease power generation efficiency. Evidencing that the CO2 capture needs additional technical effort and establishing that further developments in this area must be constrained by reducing its energy requirements. After a comprehensive literature revision, six different chemical absorption methods are analyzed based on a simplified energetic model, in order to account for its energetic costs. Furthermore, an application case study is provided where the different CO2 capture systems studied are coupled to a natural gas cogeneration power plant.


Author(s):  
S. Can Gülen

In 1992, United States Department of Energy's (DOE) Advanced Turbine Systems (ATS) program established a target of 60% efficiency for utility scale gas turbine (GT) power plants to be achieved by the year 2000. Although the program led to numerous technology breakthroughs, it took another decade for an actual combined cycle (CC) power plant with an H class GT to reach (and surpass) the target efficiency. Today, another target benchmark, 65% efficiency, circulates frequently in trade publications and engineering journals with scant support from existing technology, its development path as well as material limits, and almost no regard to theoretical (e.g., underlying physics) and practical (e.g., cost, complexity, reliability, and constructability) concerns. This paper attempts to put such claims to test and establish the room left for gas turbine combined cycle (GTCC) growth in the next two decades. The analysis and conclusions are firmly based on fundamental thermodynamic principles with carefully and precisely laid out assumptions and supported by rigorous calculations. The goal is to arm the practicing engineer with a consistent, coherent, and self-standing reference to critically evaluate claims, predictions, and other futuristic information pertaining to GTCC technology.


Author(s):  
S. Can Gülen ◽  
Indrajit Mazumder

Cost of electricity (COE) is the most widely used metric to quantify the cost-performance trade-off involved in comparative analysis of competing electric power generation technologies. Unfortunately, the currently accepted formulation of COE is only applicable to comparisons of power plant options with the same annual electric generation (kilowatt-hours) and the same technology as defined by reliability, availability, and operability. Such a formulation does not introduce a big error into the COE analysis when the objective is simply to compare two or more base-loaded power plants of the same technology (e.g., natural gas fired gas turbine simple or combined cycle, coal fired conventional boiler steam turbine, etc.) and the same (or nearly the same) capacity. However, comparing even the same technology class power plants, especially highly flexible advanced gas turbine combined cycle units with cyclic duties, comprising a high number of daily starts and stops in addition to emissions-compliant low-load operation to accommodate the intermittent and uncertain load regimes of renewable power generation (mainly wind and solar) requires a significant overhaul of the basic COE formula. This paper develops an expanded COE formulation by incorporating crucial power plant operability and maintainability characteristics such as reliability, unrecoverable degradation, and maintenance factors as well as emissions into the mix. The core impact of duty cycle on the plant performance is handled via effective output and efficiency utilizing basic performance correction curves. The impact of plant start and load ramps on the effective performance parameters is included. Differences in reliability and total annual energy generation are handled via energy and capacity replacement terms. The resulting expanded formula, while rigorous in development and content, is still simple enough for most feasibility study type of applications. Sample calculations clearly reveal that inclusion (or omission) of one or more of these factors in the COE evaluation, however, can dramatically swing the answer from one extreme to the other in some cases.


2014 ◽  
Vol 25 (8) ◽  
pp. 1148-1173 ◽  
Author(s):  
Shyong Wai Foon ◽  
Milé Terziovski

Purpose – The purpose of this paper is to examine the impact of operations and maintenance (O&M) practices, individually and collectively, on power plant performance. Design/methodology/approach – Data were collected from more than 100 power plants in Australia and Malaysia. The reliability and validity (content, construct, and criterion) of the practice and performance measures were evaluated. Findings – Committed leadership and maintenance-oriented practices as part of a total productive maintenance (TPM) philosophy were found to be the main differentiators between high and low performing plants. Research limitations/implications – The research is cross-sectional in nature, therefore, it does not permit us to account for the lag between implementation and performance. Second, the performance measures are subjective and may be subject to response bias. Practical implications – The implication of the research findings for plant managers is that they need to allocate more “softer” resources to the O&M function if they expect high plant availability. Social implications – Apart from capacity and fuel cost, operating costs are an important source of differentiation for power plants. The implication is that reduction in operating costs is directly related to the reduction of consumer power bills. Originality/value – The reader will learn from this paper that committed leadership and maintenance-oriented practices have greater explanatory power in the regression models than employee involvement, customer focus, strategic planning, and knowledge management. This knowledge is important because it emphasises that in addition to quality management practices, which are focussed on the development of the people aspects of the organization, the plant equipment and physical assets should also be given equal emphasis, in order to improve operational performance of power plants.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Rajive Ganguli ◽  
Sukumar Bandopadhyay

The impact of particle size distribution (PSD) of pulverized, low rank high volatile content Alaska coal on combustion related power plant performance was studied in a series of field scale tests. Performance was gauged through efficiency (ratio of megawatt generated to energy consumed as coal), emissions (SO2,NOx, CO), and carbon content of ash (fly ash and bottom ash). The study revealed that the tested coal could be burned at a grind as coarse as 50% passing 76 microns, with no deleterious impact on power generation and emissions. The PSD’s tested in this study were in the range of 41 to 81 percent passing 76 microns. There was negligible correlation between PSD and the followings factors: efficiency, SO2,NOx, and CO. Additionally, two tests where stack mercury (Hg) data was collected, did not demonstrate any real difference in Hg emissions with PSD. The results from the field tests positively impacts pulverized coal power plants that burn low rank high volatile content coals (such as Powder River Basin coal). These plants can potentially reduce in-plant load by grinding the coal less (without impacting plant performance on emissions and efficiency) and thereby, increasing their marketability.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3798
Author(s):  
Hamid Iftikhar ◽  
Eduardo Sarquis ◽  
P. J. Costa Branco

Existing megawatt-scale photovoltaic (PV) power plant producers must understand that simple and low-cost Operation and Maintenance (O&M) practices, even executed by their own personal and supported by a comparison of field data with simulated ones, play a key role in improving the energy outputs of the plant. Based on a currently operating 18 MW PV plant located in an under-developing South-Asia country, we show in this paper that comparing real field data collected with simulated results allows a central vision concerning plant underperformance and valuable indications about the most important predictive maintenances actions for the plant in analysis. Simulations using the globally recognized software PVSyst were first performed to attest to the overall power plant performance. Then, its energy output was predicted using existing ground weather data located at the power plant. Compared with the actual plant’s annual energy output, it was found that it was underperforming by −4.13%, leading to a potential monetary loss of almost 175,000 (EUR)/year. Besides, an analysis of the O&M power plant reports was performed and compared to the best global practices. It was assessed that the tracker systems’ major issues are the forerunner of the most significant PV power plant underperformance. In addition, issues in inverters and combiner boxes were also reported, leading to internal shutdowns. In this case, predictive maintenance and automated plant diagnosis with a bottom-up approach using low-cost data acquisition and processing systems, starting from the strings level, were recommended.


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