The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

J K Kaldellis - One of the best experts on this subject based on the ideXlab platform.

  • energy balance analysis of wind based pumped hydro storage systems in remote island Electrical networks
    Applied Energy, 2010
    Co-Authors: J K Kaldellis, M Kapsali, K A Kavadias
    Abstract:

    Abstract The introduction of pumped hydro storage (PHS) systems in isolated Electrical Grids, such as those found in island regions, appears to be a promising solution that is able to face both the high electricity production cost and the continuously increasing power demand encountered in these areas. In this context, the current work presents a methodology for the sizing of PHS systems that exploit the excess wind energy amounts produced by local wind farms, otherwise rejected due to imposed Electrical grid limitations. The methodology is accordingly applied to the Greek island of Lesbos. Initially, a calculation of the wind power penetration ability to the local grid is carried out and the corresponding curtailments of existing and future wind farms are determined. An integrated computational algorithm is then presented which simulates the operation of the system during an entire year and gives in detail the hourly operational status as well as the various energy losses of the system main components. Based on the application results obtained, the ability of the wind energy to remarkably contribute to the electrification of the remote islands becomes evident.

  • the wind potential impact on the maximum wind energy penetration in autonomous Electrical Grids
    Renewable Energy, 2008
    Co-Authors: J K Kaldellis
    Abstract:

    According to long-term wind speed measurements the Aegean Archipelago possesses excellent wind potential, hence properly designed wind energy applications can substantially contribute to fulfill the energy requirements of the island societies. On top of this, in most islands the electricity production cost is extremely high, while significant insufficient power supply problems are often encountered, especially during the summer. Unfortunately, the stochastic behaviour of the wind and the important fluctuations of daily and seasonal electricity load pose a strict penetration limit for the contribution of wind energy in the corresponding load demand. The application of this limit is necessary in order to avoid hazardous electricity grid fluctuations and to protect the existing thermal power units from operating near or below their technical minima. In this context, the main target of the proposed study is to present an integrated methodology able to estimate the maximum wind energy penetration in autonomous Electrical Grids on the basis of the available wind potential existing in the Aegean Archipelago area. For this purpose a large number of representative wind potential types have been investigated and interesting conclusions have been derived.

  • maximum wind energy contribution in autonomous Electrical Grids based on thermal power stations
    Applied Thermal Engineering, 2007
    Co-Authors: J K Kaldellis
    Abstract:

    Greek islands cover their continuously increasing electricity demand on the basis of small autonomous thermal power stations. This electrification solution is related with increased operational cost and power insufficiency, especially during summer. On the other hand, the stochastic behaviour of the wind and the important fluctuations of daily and seasonal electricity load in almost all Greek islands pose a substantial penetration limit for the exploitation of the high wind potential of the area. In this context, the present study is concentrated on developing an integrated methodology which can estimate the maximum wind energy contribution to the existing autonomous Electrical Grids, using the appropriate stochastic analysis. For this purpose one takes into account the Electrical demand probability density profile of every island under investigation as well as the operational characteristics of the corresponding thermal power stations. Special attention is paid in order to protect the existing internal combustion engines from unsafe operation below their technical minima as well as to preserve the local system active power reserve and the corresponding dynamic stability. In order to increase the reliability of the results obtained, one may use extensive information for several years. Finally, the proposed study is integrated with an appropriate parametrical analysis, investigating the impact of the main parameters variation on the expected maximum wind energy contribution.

Konstantin Turitsyn - One of the best experts on this subject based on the ideXlab platform.

  • micro water energy nexus optimal demand side management and quasi convex hull relaxation
    IEEE Transactions on Control of Network Systems, 2019
    Co-Authors: Ameena Saad Alsumaiti, Konstantin Turitsyn
    Abstract:

    In some countries and regions, water distribution and treatment consume a considerable amount of electric energy. This paper investigates the water network's potential ability to provide demand response services to the power grid for the management of renewable resources under the framework of a distribution-level water–energy nexus (micro WEN). In particular, the hidden controllable water loads, such as irrigation systems, were closely studied as virtual energy storage to improve the flexibility of Electrical Grids. An optimization model is developed for the demand-side management (DSM) of micro WEN, and the simulation results assert that grid flexibility indeed benefits from taking controllable water loads into account. Although the proposed optimal DSM model is a computationally intractable mixed-integer nonlinear programming (MINLP) problem, quasi-convex hull techniques were developed to relax the MINLP into a mixed-integer convex programming (MICP) problem. The numerical study shows that the quasi-convex hull relaxation is tight and that the resulting MICP problem is computationally efficient.

  • micro water energy nexus optimal demand side management and quasi convex hull relaxation
    arXiv: Optimization and Control, 2018
    Co-Authors: Ameena Saad Alsumaiti, Konstantin Turitsyn
    Abstract:

    This paper investigates the water network's potential ability to provide demand response services to the power grid under the framework of a distribution-level water-energy nexus (micro-WEN). In particular, the hidden controllability of water loads, such as irrigation systems, was closely studied to improve the flexibility of Electrical Grids. A optimization model is developed for the demand-side management (DSM) of micro-WEN, and the simulation results assert that grid flexibility indeed benefits from controllable water loads. Although the proposed optimal DSM model is an intractable mixed-integer nonlinear programming (MINLP) problem, quasi-convex hull techniques were developed to relax the MINLP into a mixed-integer convex programming (MICP) problem. The numerical study shows that the quasi-convex hull relaxation is tight and that the resulting MICP problem is computationally efficient.

G Marangoni - One of the best experts on this subject based on the ideXlab platform.

  • including system integration of variable renewable energies in a constant elasticity of substitution framework the case of the witch model
    Energy Economics, 2017
    Co-Authors: Samuel Carrara, G Marangoni
    Abstract:

    The penetration of Variable Renewable Energies (VREs) in the electricity mix poses serious challenges in terms of management of the Electrical Grids, as the associated variability and non-dispatchability are in contrast with the requirement that the load be instantaneously equalized by the generation. One of the goals of Integrated Assessment Models (IAMs) is to simulate the evolution of electricity demand and generation mix over time, therefore a proper modeling of VRE system integration is crucial. In this paper we discuss how different modeling mechanisms can profoundly impact the evolution of the electricity mix, and specifically renewable penetration. In particular, we focus on the effects of introducing a set of explicit system integration constraints in a model, WITCH, characterized by a Constant Elasticity of Substitution (CES) framework.

  • including system integration of variable renewable energies in a constant elasticity of substitution framework the case of the witch model
    Energy Economics, 2017
    Co-Authors: Samuel Carrara, G Marangoni
    Abstract:

    Abstract The penetration of variable renewable energies (VREs) in the electricity mix poses serious challenges in terms of management of the Electrical Grids, as the associated variability is in contrast with the requirement that the load be instantaneously equalized by the generation. One of the goals of Integrated Assessment Models (IAMs) is to simulate the evolution of electricity demand and generation mix over time, therefore a proper modeling of VRE system integration is crucial. In this paper we discuss how different modeling mechanisms can profoundly impact the evolution of the electricity mix, and specifically renewable penetration. In particular, we focus on the effects of introducing a set of explicit system integration constraints in a model, WITCH, characterized by a Constant Elasticity of Substitution (CES) framework. The role of the implementation of storage is discussed as well.

Ameena Saad Alsumaiti - One of the best experts on this subject based on the ideXlab platform.

  • micro water energy nexus optimal demand side management and quasi convex hull relaxation
    IEEE Transactions on Control of Network Systems, 2019
    Co-Authors: Ameena Saad Alsumaiti, Konstantin Turitsyn
    Abstract:

    In some countries and regions, water distribution and treatment consume a considerable amount of electric energy. This paper investigates the water network's potential ability to provide demand response services to the power grid for the management of renewable resources under the framework of a distribution-level water–energy nexus (micro WEN). In particular, the hidden controllable water loads, such as irrigation systems, were closely studied as virtual energy storage to improve the flexibility of Electrical Grids. An optimization model is developed for the demand-side management (DSM) of micro WEN, and the simulation results assert that grid flexibility indeed benefits from taking controllable water loads into account. Although the proposed optimal DSM model is a computationally intractable mixed-integer nonlinear programming (MINLP) problem, quasi-convex hull techniques were developed to relax the MINLP into a mixed-integer convex programming (MICP) problem. The numerical study shows that the quasi-convex hull relaxation is tight and that the resulting MICP problem is computationally efficient.

  • micro water energy nexus optimal demand side management and quasi convex hull relaxation
    arXiv: Optimization and Control, 2018
    Co-Authors: Ameena Saad Alsumaiti, Konstantin Turitsyn
    Abstract:

    This paper investigates the water network's potential ability to provide demand response services to the power grid under the framework of a distribution-level water-energy nexus (micro-WEN). In particular, the hidden controllability of water loads, such as irrigation systems, was closely studied to improve the flexibility of Electrical Grids. A optimization model is developed for the demand-side management (DSM) of micro-WEN, and the simulation results assert that grid flexibility indeed benefits from controllable water loads. Although the proposed optimal DSM model is an intractable mixed-integer nonlinear programming (MINLP) problem, quasi-convex hull techniques were developed to relax the MINLP into a mixed-integer convex programming (MICP) problem. The numerical study shows that the quasi-convex hull relaxation is tight and that the resulting MICP problem is computationally efficient.

Adriano Carvalho - One of the best experts on this subject based on the ideXlab platform.

  • controllable hybrid power system based on renewable energy sources for modern Electrical Grids
    Renewable Energy, 2013
    Co-Authors: J E Paiva, Adriano Carvalho
    Abstract:

    Abstract This paper analyses and proposes a different role for small distributed generation (DG) systems based on renewable sources, in the context of modern Electrical Grids. The main purpose of the system is to act as a grid services provider and not as a stochastic and dynamically unpredictable energy generator. Simulation models are defined and integrated in a hybrid renewable energy system (HRES) with storage, to study its behavior under suitable operation strategies. Being a small system with a production cost higher than a conventional one, its operation as a grid services provider, rather than only an energy generator, is proposed and analyzed firstly by simulation then validated by results from an experimental setup. Carried out results allow concluding that this a suitable system in the current context, either for distributed and smart Grids, or for Electrical market.