Large Power Plants Research Articles

Dynamic Risk Assessment of Landslide Hazard for Large-Scale Photovoltaic Power Plants under Extreme Rainfall Conditions

Large-scale photovoltaic power plants located in highland mountainous areas are vulnerable to landslides due to extreme rainfall, posing a significant threat to the normal operation of photovoltaic power plants. However, limited research has been conducted on landslide risk assessment specifically tailored to large photovoltaic power plants, with most studies focusing on static assessments that lack long-term sustainability in risk assessment and prediction. In this paper, a dynamic study on landslide risk at a large photovoltaic power plant project under extreme rainfall conditions is conducted. Firstly, the factors in landslide susceptibility assessment based on typical landslide characteristics in the study area are selected and an assessment index database using mapping units to extract the relevant factors is established. Subsequently, the ANP-FBN model is employed to evaluate the landslide susceptibility of large photovoltaic power plant sites. Furthermore, an assessment index system for landslide hazard vulnerability is developed by considering population, economic, and material vulnerabilities, and the AHP method is adapted to assess landslides vulnerability in the study area. Finally, the landslide rainfall threshold with the susceptibility and vulnerability assessment results are coupled to achieve a dynamic assessment of landslide hazard risk at large photovoltaic power plant sites under extreme rainfall conditions. The findings highlight that the central valley and the eastern steep slope of the study area are the primary “high” and “very high” risk areas. Moreover, with the increase in rainfall duration, the risk level of landslide hazards in the study area also rises.

Rapid growth and high cloud-forming potential of anthropogenic sulfate aerosol in a thermal power plant plume during COVID lockdown in India

The COVID lockdown presented an interesting opportunity to study the anthropogenic emissions from different sectors under relatively cleaner conditions in India. The complex interplays of power production, industry, and transport could be dissected due to the significantly reduced influence of the latter two emission sources. Here, based on measurements of cloud condensation nuclei (CCN) activity and chemical composition of atmospheric aerosols during the lockdown, we report an episodic event resulting from distinct meteorological conditions. This event was marked by rapid growth and high hygroscopicity of new aerosol particles formed in the SO2 plume from a large coal-fired power plant in Southern India. These sulfate-rich particles had high CCN activity and number concentration, indicating high cloud-forming potential. Examining the sensitivity of CCN properties under relatively clean conditions provides important new clues to delineate the contributions of different anthropogenic emission sectors and further to understand their perturbations of past and future climate forcing.

Approaches for smart linear regression in a difficult quasi economic dispatch problem

<span lang="EN-US">Traditional methods indispensably necessitate monotonically increasing characteristic for fuel cost of generators in a thermal power plant. However, in medium and large thermal power plants, this condition is a dream to accomplish. So, to meet out these exigencies heuristic methods like swarm optimization technique, genetic algorithm technique and bee colony based hybrid solar thermal technology (BHSTT) are used to realize the practical nonlinearities associated with valve point loading emanated out of multi-valving effect, associated with power station. However, the heuristic methods too face challenges arising out of bulky thermal power plants adopting cubic cost functions and possessing stringent non-convex economic dispatch problem following multi-valving and erratic behavior of nonlinear loads at the load center. So, at its favor function evaluation method dealing with cubic cost function is attempted in this dissertation to yield a satisfactory optimal solution for economic dispatch problem. This method deals with the real power generation of producing units as well as the complex power of units, as well as dealing with severe nonlinear stringent fuel cost characteristics that are prevalent in today’s bulky thermal power plants. In comparison to previous approaches, the findings achieved are highly encouraging.</span>

Comparison of harmonic emission in LV side of a large grid connected PV power plant

The use of solar photovoltaic (PV) in distribution networks has increased considerably in recent years. Although they have many advantages, PV systems can also result in complex power quality issues in distribution networks, like harmonic distortion, that can interfere with loads and controllers. Harmonic emission from different inverters and their aggregation is thus of interest. In this work, harmonic emission of two PV string inverters and two substations operating in a large PV power plant is presented. The distribution of the full range of current harmonics is analyzed, as well as the correlation between the values of each harmonic and the power level produced, by the inverter or substation, and the correlation between voltage and current harmonics. Significant differences are observed in the harmonic emission of the inverters, despite being under the same operating loading and grid conditions. The results obtained for the substations are in line to those for the inverters. This study was performed in a grid connected 12 MW PV power plant operating in Europe.

40MW급 디젤 발전 장비의 실용적인 축계정렬 연구

Diesel power plants come in a variety of shapes, from moveable mini-power plants installed in 40-feet standard container boxes to large capacity power plants. The world's largest diesel power plant listed in the Guinness Book of World Records is Jordan's Amman Asian power plant, which produces a total of 573 MW of electric power. It consists of 38 units of 15MW capacity, and KEPCO achieved high profitability through the power plant. If a large capacity of 40MW clsss is applied, it will be newly listed in the Guinness Book of World Records even if only 15 units are constructed. Therefore, large-scale overseas orders for diesel power plants that require large capacity are expected in the future. The purpose of this study is to derive a practical offset by performing the shaft alignment analysis for large capacity 40MW shaft system, and to infer the change of offset for larger capacity shaft system through the comparison with the 30MW shaft alignment which is the result of the previous research. As a result, the practical offset of shaft system for the 40MW diesel power generation equipment was derived through the bearing influence assessment. From the comparison of shaft alignment between 30MW and 40MW, it is considered to be a complex offset to calculate the height of the engine bearing from 50MW class.

Simple Chargers for a Small DC Micro-Grid for a Home Emergency Power System

Recently, the danger of a long blackout is discussed in Europe. Blackouts can be caused by failures in the energy distribution, errors in large power plants or even cyber-attacks. This can lead to a chain reaction and a disintegration of the mains. Longer blackouts have an extreme impact on the economy as a whole and on local households. Therefore, a small local grid at home which can supply the most important loads over some time has garnered increasing interest. With a small direct current (DC) grid, critical loads such as for deep freezers and refrigerators can be supplied, and some LED lights can be used in the evening or at night. Solar generators (panels) can be used to charge energy storage devices, e.g., batteries. A DC grid can not only be used in the case of an emergency, but can also be used to reduce energy consumption out of the public mains and reduce energy bills. The architecture of the household emergency DC grid is discussed; suggestions for batteries are given; two simple chargers, based on DC-DC-converters like the Buck (step-down) and on the Boost (step-up) converters, are shown; dimensioning suggestions are given; and simple, robust controllers, a P-controller with disturbance feedforward and a hysteresis controller, are treated and tested via simulations. The goal of the paper is to show a simple autonomous home energy system without an external fieldbus, LAN or internet connection with special focus on simple charger topologies.

Economic analysis of a large scale solar updraft tower power plant

This research article provides an economic analysis of a large-scale solar updraft tower power plant (SUTPP) having 100 MW capacity and installed in Udat, Rajasthan, India, with position coordinates of 27° 35′ and 72° 43′ for meteorological conditions. A cost model developed for optimized parametric values, received from thermal and dimensional optimization of previous study, to analyse the optimized cost of electricity generation and revenue analysis with the consideration of electricity selling, carbon credits, and the levelized electricity cost. The results of the analysis suggest that the proposed plant has a higher capital and operating cost than photovoltaic and wind energy, but it also has a lower levelized cost of electricity generation. As, for a fixed power output, the optimized cost of electricity generation is inversely proportional to Rcollector and Rtower, and obtained an optimum value between ₹9.16 to ₹10.57 for power plants ranging from 100 MW to 200 MW. The results also show that the cost of construction of such a power plant largely depends on plant configuration and can lie between ₹4.5cr. to ₹12cr. per MW, which indicates that a large-scale SUTPP can be installed economically. Although the optimum values of optimized cost of electricity generation came with larger dimensional values of the power plant, that also create challenges during the construction and operation of the power plant. Based on these findings, the authors conclude that, with proper subsidies and support, a large-scale SUTPP can be considered a promising renewable energy technology for power generation.

Model Design of Helical Type Vertical Shaft Wind Turbine with Capacity of 5 W

A vertical axis wind turbine (VAWT) is a power generator that uses wind power to generate torque. The VAWT can be pointed in any direction, meaning it doesn't need to be pointed into the wind to generate power. Thus, there is potential for large power plants using VAWTs as their size can be significantly increased. However, there are also some drawbacks to the VAWT. VAWT has the characteristics of self-starting. But still, an additional power source is needed to start the turbine rotation until a certain rotation speed is reached or it must operate at high wind speeds. The main objective of our work is to create a 5 W VAWT model (helical type) to optimize self-starting of vertical axis wind turbines. The outline of this report is regarding the design of our VAWT model, which will have self-starting characteristics. To increase the self-starting status, our efforts are to optimize the type, dimensions and material of the turbine blades. We also optimized the rotor dimensions. As a result, a model helical three-blade turbine was built and tested. The blade turbine made of composites has been balanced with the rotor prior to testing. The test uses 2 fans with a speed of 3-5m/s, the test is carried out to obtain wind turbine performance data.

Exergo-economic and exergo-environmental assessment of two large CHP geothermal power plants

An Exergo-Economic and Exergo-Environmental Analysis is presented for two large geothermal power plants located in Iceland – Hellisheidi and Nesjavellir. The latest configuration of the power plants - including for Hellisheidi acid gas removal and Carbon capture - is analyzed. Cost and LCA data available within the EU H2020 GECO project were processed with an exergy approach, with the purpose to identify the major points of cost build-up or environmental impact along the energy conversion process. A considerable relevance of the cost and impact due to the activity of wells drilling was confirmed for geothermal energy systems; within the operation of the plant, the major effects of exergy destruction are found at the turbines and condensers. The inefficiencies and the buildup of cost and environmental impact along the energy conversion chain are highlighted and the outcomes are discussed with a comparison between the two plants. These are confirmed as performing very well both from the economics and sustainability points of view: recent and foreseen improvements for emissions and carbon capture will not change substantially the economics and will be very effective from the point of view of environmental performance.

Arundhati Roy’s Critique of Big Projects: An Eco-critical Perspective

The present article endeavors to analyze Arundhati Roy’s critique of big dams and projects. An attempt is made to bring home various dimensions and commitments that inform her critique of the big dams which cause more damage and devastation than serving the needs of the people at large. The primary focus is on Ms. Roy’s participation in the Narmada Bachao Andolan which is an Indian resistance movement that tries to prevent building of large dams, reservoirs and power plants. As the building of projects may lead to evacuation of villages and to lose immovable properties numerous environmentalists, humanists, activists and other personalities also have condemned the government for the decisions and implementations. Arundhati Roy is one among them who raises awareness of dangers of massive dams, of resulting forced relocation of people and of damage to environment. The present article is going to discuss the tireless and selfless service of Arundhati Roy and the NBA to tens of thousands of farmers, Adivasis and common people who are participating in the protest to oppose the aforementioned large structures constructed by the Narmada Valley Development Authority (NVDA). In conclusion, the article also attempts to bring out the various aspects and convictions that informed Roy’s critique of big projects.

Analysis energy production design from grid connected 40 MW large PV power plant

Electricity is an important source of energy in everyday life. In recent decades, growing energy demand worldwide has significantly fueled energy production, leading to environmental impacts such as global warming and ozone depletion. it has also endangered the species. Hence, the whole world has started shifting towards green energy generation, eliminating all the negative impacts on the environment. Solar energy is the most CO2 emission save compared to non-renewable energy sources. A photovoltaic generator is useful in areas well exposed to the sun. This paper is aimed the total amount of energy generated by the solar system connected to the grid on the 230 kV transmission line. This result was conducted by comparing the energy generated with tilt angle of 15°,20°,25°,30°and 35°. The most energy generated is produced with 25° of tilt angle according to the simulation result in this paper. The result was simulated by using PVsyst. This paper presents energy production of a 40-MW grid connected photovoltaic system located at Minbu Township in Myanmar. The simulation is carried out in order to get maximum energy production and the incident radiation, performance ratio, energy into the grid and energy output at array and losses. Based on the simulation result, it is concluded that maximum energy production and performance ratio are 75730 MWh and 81% through the year. The CO2 emission was saved 424781.5 tons per year. The incident energy in collector plane is 5.220kWh/m2/day. This research is only conducted for analysis on existing grid connected utility scale solar PV system and not provided for advanced techniques.

Laboratory studies of fish entrainment sampling using a screw centrifugal impeller pump

AbstractObjectiveRegulatory legislation in both the United States and Canada requires water users with medium to high intake volumes to monitor entrainment losses to determine effects and to assess potential mitigation strategies to reduce harm to fish. Recent studies have recommended the use of both increased sampling frequency and sampling volume to characterize fish entrainment for large power plants on the Great Lakes. There is little doubt that increasing the flow rate and volume of water collected for sampling reduces the uncertainty in estimates of annual entrainment. Depending on the type of pump and the pumping flow rate used for entrainment sampling, considerable damage to fish larvae can occur. A screw‐type centrifugal pump has many qualities that make it ideal for entrainment sampling, but it has not yet been used as a sampling device for fish entrainment applications at power plants or other large industrial water users. The objective of this study was to determine mortality of entrainable fish eggs and larvae due to passage through a screw‐type centrifugal pump.MethodsIn a laboratory setting, Lake Trout Salvelinus namaycush eggs and larvae, Lake Whitefish Coregonus clupeaformis eggs, and Rainbow Trout Oncorhynchus mykiss juveniles were passed through a screw‐type centrifugal pump at three treatment flow rates: 39.5, 47.3, and 59.1 m3/h. Fish and eggs were monitored for mortality posttreatment and again at 24 and 48 h.ResultAcross treatments, very few mortalities were observed. Species specific moralities were four larval Lake Trout, one Lake Whitefish egg, and one juvenile Rainbow Trout. No mortality was observed for Lake Trout eggs.ConclusionThe present study identified high egg and larval survival (≥99%) after passage through a screw‐type centrifugal pump. High survival reduces error associated with identification and counting of entrained organisms, which provides more accurate estimates of annual entrainment losses.

A reference architecture for orbiting solar reflectors to enhance terrestrial solar power plant output

Orbiting reflectors offer the possibility of illuminating large terrestrial solar power plants to enhance their output, particularly at dawn and dusk when their output is low but energy spot prices can be high. While the concept of orbiting solar reflectors has been considered in various forms in the past, there is now a timely overlap of rapidly growing global demand for clean energy services, falling launch costs through reusability and the emergence of in-orbit manufacturing technologies to enable the fabrication of large, ultra-lightweight space structures. This paper provides an end-to-end analysis of a possible minimum initial architecture to deliver such global clean energy services. The analysis will cover orbit selection, attitude control requirements, structural analysis and economical viability, followed by a discussion on regulatory issues, future improvements and further applications.

Flexible solar cells based on foldable silicon wafers with blunted edges

Flexible solar cells have a lot of market potential for application in photovoltaics integrated into buildings and wearable electronics because they are lightweight, shockproof and self-powered. Silicon solar cells have been successfully used in large power plants. However, despite the efforts made for more than 50 years, there has been no notable progress in the development of flexible silicon solar cells because of their rigidity1–4. Here we provide a strategy for fabricating large-scale, foldable silicon wafers and manufacturing flexible solar cells. A textured crystalline silicon wafer always starts to crack at the sharp channels between surface pyramids in the marginal region of the wafer. This fact enabled us to improve the flexibility of silicon wafers by blunting the pyramidal structure in the marginal regions. This edge-blunting technique enables commercial production of large-scale (>240 cm2), high-efficiency (>24%) silicon solar cells that can be rolled similarly to a sheet of paper. The cells retain 100% of their power conversion efficiency after 1,000 side-to-side bending cycles. After being assembled into large (>10,000 cm2) flexible modules, these cells retain 99.62% of their power after thermal cycling between −70 °C and 85 °C for 120 h. Furthermore, they retain 96.03% of their power after 20 min of exposure to air flow when attached to a soft gasbag, which models wind blowing during a violent storm.

Using GPUs to simulate photovoltaic power plants: Special cases of performance loss

The installed capacity of renewable energy is soaring, and Photovoltaic Power is a sizeable part of it. Photovoltaic panels are being installed on both buildings and in large Photovoltaic Power Plants (PVPPs), reaching up to 2 GW of installed capacity. We need to perform simulations of the state of PVPPs to ensure the stability of the power system and their profitability. Traditional simulations that take into consideration each panel can accurately predict the generated power but are too computationally taxing. To lower the computing cost of these simulations, a GPU-based solver that processes the dynamic model of a PVPP connected to a power system has been developed. It simulates the output of the whole photovoltaic power plant down to the photovoltaic panel level. The characteristics of the power system to be simulated were analyzed in order to parallelize the system. The two-diode model is used for the PV panels, and this model was linearized, resulting in a large sparse matrix with millions of columns that must be solved. Our proposal can simulate a model of the PVPP with both accuracy and low computational cost with no PV panel aggregation required. The system was solved using an adaptive step and helper conductances to aid convergence of the matrix. Parallel column factorization and column grouping is key to achieving a high performant simulation, which makes it feasible to simulate events such as cloud occlusion efficiently. We also studied how the wiring of PV panels affects the global power plant output when panels are shaded and/or broken. It was found that the aggregated model returns a higher generated output, which is key to predicting its output and its profitability. PVPP simulations on the GPU solver are up to 14.3 times faster than on the CPU.

Review of Deep Reinforcement Learning and Its Application in Modern Renewable Power System Control

With the ongoing transformation of electricity generation from large thermal power plants to smaller renewable energy sources (RESs), such as wind and solar, modern renewable power systems need to address the new challenge of the increasing uncertainty and complexity caused by the deployment of electricity generation from RESs and the integration of flexible loads and new technologies. At present, a high volume of available data is provided by smart grid technologies, energy management systems (EMSs), and wide-area measurement systems (WAMSs), bringing more opportunities for data-driven methods. Deep reinforcement learning (DRL), as one of the state-of-the-art data-driven methods, is applied to learn optimal or near-optimal control policy by formulating the power system as a Markov decision process (MDP). This paper reviews the recent DRL algorithms and the existing work of operational control or emergency control based on DRL algorithms for modern renewable power systems and control-related problems for small signal stability. The fundamentals of DRL and several commonly used DRL algorithms are briefly introduced. Current issues and expected future directions are discussed.

Design of heat pipe cooled microreactor based on cycle analysis and evaluation of applicability for remote regions

In spite the efforts to specify the design of heat pipe cooled microreactors, there are lack of conclusive information on microreactors based on cycle analysis. To provide a design guideline for power conversion systems and management, large nuclear power plants (NPPs) were compared in terms of electricity transmission and distribution (T&D) losses and the microreactors were assessed for transportability. To this end, a cycle code was developed, and a thermodynamic analysis and an economic evaluation were conducted. Two different operating conditions with a maximum cycle efficiency of 52.0% and a minimum levelized cost of electricity (LCOE) of 81.82 USD/MWh were derived using the developed code. The best economic microreactor cycle condition was compared with a commercial large NPP. When considering T&D losses, the microreactor seemed more economical if operated for more than 4.3y in Hungary, where the T&D losses are high, and for 13.8y in Germany, where the electricity cost is high. However, the microreactor is more economical than the large NPP only for short period because the designed lifetime of microreactors is currently being investigated. We also designed small power generation systems for microreactor’s transportability; the small power generation systems with the microreactor demonstrated better economics compared with other small power generation systems when using oil, ammonia, and Liquefied Natural Gas (LNG) as fuels to evaluate the availability of the microreactor in the remote regions. The findings indicate that the microreactor could be more economical when generating the same amount of electricity compared to that using power generation systems if the detailed designs satisfy the design points developed from the cycle analysis.

Holistic scan optimization of nacelle-mounted lidars for inflow and wake characterization at the RAAW and AWAKEN field campaigns

In this article, we provide a methodological framework for designing the scanning strategies of nacelle-mounted scanning lidars for wind energy field experiments, and apply it at two major experimental field campaigns. For the Rotor Aerodynamics, Aeroelastics, and Wake project (RAAW), we leverage two scanning lidars on one turbine to characterize the incoming turbulence and the turbine wake. For the American WAKE experimeNt (AWAKEN), we use four scanning lidars on top of four turbines in a large wind power plant to investigate both individual wakes and wind-plant-scale flow features.

Study on Control System of Bridge-Type Grab Ship Unloader

In order to improve the automation degree and unloading efficiency of the ship unloading control system of the large coal-fired power plant, the structure, operation principle and workflow of the bridge-type grab ship unloader in a coal-fired power along the river are analysed, and the control system of ship unloader software based on PLC is studied and designed. The designed control system of bridge grab ship unloader is convenient to operate under different working conditions and improves the automation degree and efficiency of coal unloading and also provides an application example for the development of ship unloader control research.

Development Economics of Irrigated Agriculture in Ukraine

The development of irrigated agriculture is a strategic direction of sustainable development of the agrarian sector of economy, ensuring national food security, increasing export potential and efficient use of land and resource potential. The purpose of the article is to systematically analyze the economic framework for the development of irrigated agriculture in Ukraine. The methodological basis of the study is a systematic approach, within which the following general scientific and special methods have been used: analysis, synthesis, generalization, abstraction, historical and comparative analysis, monographic and systemic analysis, formalization, and graphing. The historical and economic background of the development of irrigated agriculture in Ukraine has been analyzed, with five stages of its genesis identified: 1840–1917 (the beginning of irrigation and justification of its feasibility on the ground); 1918–1941 (construction of the first irrigation systems, collective and state farm amelioration networks); 1946–1960 (post-war reconstruction of irrigation systems and construction of large hydroelectric power plants and reservoirs); 1961–1990 (construction of large state and inter-farm irrigation systems, active development of irrigated agriculture); 1991–2021 (gradual decline of the state irrigation network; development of drip irrigation). The size and structure of sown areas on irrigated lands in Ukraine, the structure of sown areas under drip irrigation, and the comparative yield of major crops in agricultural enterprises of Ukraine under irrigation conditions have been systematically studied. It has been shown that economic efficiency in irrigated agriculture is formed under the influence of cost and price mechanisms, and investment decisions are based on the programmability of the yields obtained and the payback of costs by increasing production, and the development of micro-irrigation is economically feasible in small areas of high-intensity crops