Benefits of demand-side response in providing frequency response service in the future GB power system

The demand for ancillary service is expected to increase significantly in the future Great Britain (GB) electricity system due to high penetration of wind. In particular, the need for frequency response, required to deal with sudden frequency drops following a loss of generator, will increase because of the limited inertia capability of wind plants. This paper quantifies the requirements for primary frequency response and analyses the benefits of frequency response provision from demand-side response (DSR). The results show dramatic changes in frequency response requirements driven by high penetration of wind. Case studies carried out by using an advanced stochastic generation scheduling model suggest that the provision of frequency response from DSR could greatly reduce the system operation cost, wind curtailment, and carbon emissions in the future GB system characterized by high penetration of wind. Furthermore, the results demonstrate that the benefit of DSR shows significant diurnal and seasonal variation, whereas an even more rapid (instant) delivery of frequency response from DSR could provide significant additional value. Our studies also indicate that the competing technologies to DSR, namely battery storage, and more flexible generation could potentially reduce its value by up to 35%, still leaving significant room to deploy DSR as frequency response provider

Review of trends and targets of complex systems for power system optimization

Optimization systems (OSs) allow operators of electrical power systems (PS) to optimally operate PSs and to also create optimal PS development plans. The inclusion of OSs in the PS is a big trend nowadays, and the demand for PS optimization tools and PS-OSs experts is growing. The aim of this review is to define the current dynamics and trends in PS optimization research and to present several papers that clearly and comprehensively describe PS OSs with characteristics corresponding to the identified current main trends in this research area. The current dynamics and trends of the research area were defined on the basis of the results of an analysis of the database of 255 PS-OS-presenting papers published from December 2015 to July 2019. Eleven main characteristics of the current PS OSs were identified. The results of the statistical analyses give four characteristics of PS OSs which are currently the most frequently presented in research papers: OSs for minimizing the price of electricity/OSs reducing PS operation costs, OSs for optimizing the operation of renewable energy sources, OSs for regulating the power consumption during the optimization process, and OSs for regulating the energy storage systems operation during the optimization process. Finally, individual identified characteristics of the current PS OSs are briefly described. In the analysis, all PS OSs presented in the observed time period were analyzed regardless of the part of the PS for which the operation was optimized by the PS OS, the voltage level of the optimized PS part, or the optimization goal of the PS OS.Web of Science135art. no. 107

The status of river water quality in some rural areas, in state of Johor and its effects to life

Water is a basic requirement of human and other life. Water resources stems from rivers, streams, drains, ponds and so forth. The river is the natural water resources are very important for a human habitat. Malaysian water quality assessment is determined by the water quality Index (IKA) issued by the Department of environment (DOE) based on class I, II, III and IV. Now a water pollution also occurs in rural areas has affected the water quality and marine life. The objective of this writing is to determine river water quality in rural areas based on IKA. Kajian telah dijalankan di beberapa batang sungai di kawasan luar bandar di negeri Johor bermula dari bulan Februari sehingga April 2015. Water quality sampling was done three times in four different study locations. Determination of water quality involves measurement parameters pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammoniacal nitrogen (AN) and suspended solids (SS). The Measurements are made IKA the total calculated and used to classify the river either as untainted, slightly polluted moderately polluted, contaminated and polluted. The study found the status of three rivers polluted level contaminated (class IV) and a river are classified at the level of medium-polluted (class III). Deterioration of the status of IKA for all rivers surveyed not only affects marine life, even limiting water use to humans, for example, to daily activities

Operating Risk Assessment of Modern Power System in Presence of Flywheel Energy Storage

Stochastic perturbations in supply and demand during power system operations have always been a concern for power system operators and/or planners. These concerns have been aggravated in the past decade with large-scale integration of renewable energy sources (RES) such as wind and photovoltaics. The impacts of load fluctuations and/or random outages of major system components during the operation, such as loss of generating unit(s) and transmission line(s) are further aggravated due to increasing addition of intermittent RES in the system. Energy storage systems (ESS) can act as a buffer to maintain the supply-demand balance, and are therefore, gaining considerable attention in modern power system planning. It is important to have the ability to make quantitative assessment of associated risks in the system operation and to explore the potential of suitable resources such as ESS in mitigating these risks. A reliability model of flywheel energy storage system (FESS) suitable for power system operational risk evaluation was developed in the research work presented in this thesis. Appropriate reliability assessment frameworks for different hierarchical levels of power system reliability evaluation were also introduced. The proposed frameworks and models were applied to the IEEE reliability test system and a modified Roy Billinton test system through several case studies. This thesis presents a novel approach to quantify the impact of growing wind penetration on power system operational reliability and quantify the implications of implementing flywheel energy storage systems in mitigating these concerns. The work presented in this thesis provides methodology and indicators that will be valuable in developing operating policies for sustainable wind energy for the future

Electromechanical Dynamics of High Photovoltaic Power Grids

This dissertation study focuses on the impact of high PV penetration on power grid electromechanical dynamics. Several major aspects of power grid electromechanical dynamics are studied under high PV penetration, including frequency response and control, inter-area oscillations, transient rotor angle stability and electromechanical wave propagation.To obtain dynamic models that can reasonably represent future power systems, Chapter One studies the co-optimization of generation and transmission with large-scale wind and solar. The stochastic nature of renewables is considered in the formulation of mixed-integer programming model. Chapter Two presents the development procedures of high PV model and investigates the impact of high PV penetration on frequency responses. Chapter Three studies the impact of PV penetration on inter-area oscillations of the U.S. Eastern Interconnection system. Chapter Four presents the impacts of high PV on other electromechanical dynamic issues, including transient rotor angle stability and electromechanical wave propagation. Chapter Five investigates the frequency response enhancement by conventional resources. Chapter Six explores system frequency response improvement through real power control of wind and PV. For improving situation awareness and frequency control, Chapter Seven studies disturbance location determination based on electromechanical wave propagation. In addition, a new method is developed to generate the electromechanical wave propagation speed map, which is useful to detect system inertia distribution change. Chapter Eight provides a review on power grid data architectures for monitoring and controlling power grids. Challenges and essential elements of data architecture are analyzed to identify various requirements for operating high-renewable power grids and a conceptual data architecture is proposed. Conclusions of this dissertation study are given in Chapter Nine

A comprehensive review of electricity storage applications in island systems

Electricity storage is crucial for power systems to achieve higher levels of renewable energy penetration. This is especially significant for non-interconnected island (NII) systems, which are electrically isolated and vulnerable to the fluctuations of intermittent renewable generation. This paper comprehensively reviews existing literature on electricity storage in island systems, documenting relevant storage applications worldwide and emphasizing the role of storage in transitioning NII towards a fossil-fuel-independent electricity sector. On this topic, the literature review indicates that the implementation of storage is a prerequisite for attaining renewable penetration rates of over 50% due to the amplified requirements for system flexibility and renewable energy arbitrage. The analysis also identifies potential storage services and classifies applicable storage architectures for islands. Amongst the available storage designs, two have emerged as particularly important for further investigation; standalone, centrally managed storage stations and storage combined with renewables to form a hybrid plant that operates indivisibly in the market. For each design, the operating principles, remuneration schemes, investment feasibility, and applications discussed in the literature are presented in-depth, while possible implementation barriers are acknowledged. The literature on hybrid power plants mainly focuses on wind-powered pumped-hydro stations. However, recently, PV-powered battery-based hybrid plants have gained momentum due to the decreasing cost of Li-ion technology. On the other hand, standalone storage establishments rely heavily on battery technology and are mainly used to provide flexibility to the island grid. Nevertheless, these investments often suffer from insufficient remunerating frameworks, making it challenging for storage projects to be financially secure.Comment: 55 pages, 10 figure