Browsing by Author "Çelebi, Emre"

Now showing 1 - 17 of 17

Citation - WoS: 14
Citation - Scopus: 15
Alternative models for markets with nonconvexities
(Elsevier Science Bv, 2017) Fuller, J. David; Çelebi, Emre
In many electricity markets, the market operator solves a social welfare maximization (SW) model to determine market prices and generation (and consumption) "dispatch" instructions to firms participating in the market. When generation costs (or consumption benefits) are described as mixed integer programs, linear prices cannot, in general, be found such that all market participants are satisfied that the operator's dispatch instructions maximize profits, i.e., they perceive an opportunity cost. Often, "make whole" payments are made to market participants to bring negative profits up to zero, but not to adjust positive, nonoptimal profits. Make whole payments are added to "uplift" charges to customers for various non market services provided by market participants. In previous research, "uplift" is extended to include the entire opportunity costs, and prices are adjusted to minimize the part of uplift that is due to discrete variables, while keeping the SW quantity instructions. We show that the SW instructions must be modified if the non-dispatchable demand is price sensitive; to allow for this, we define a model that minimizes total opportunity cost (MTOC), and we compare it to three other models - SW, SW with non-negative profit constraints, and a minimum complementarity (MC) model recently proposed by Gabriel et al. We show that the MC model approximates the MTOC model. Two unit commitment problems illustrate the models. In an online appendix, we also present small MTOC and MC two-commodity models for which an SW model cannot be formulated due to nonintegrability of demand. (C) 2017 Elsevier B.V. All rights reserved.
Co-Optimization Models of Generation and Transmission Investments With Market-Clearing Equilibrium
(Kadir Has Üniversitesi, 2018) Uyan, Zeki; Çelebi, Emre
Methods for co-optimizing transmission and generation investments including bi-level or multi-level problems consider trade-offs with market operations and interactions in electric power supply and demand. Under fairly general conditions it is known that simultaneous solution of these multi-level models using complementarity problems can give more useful results than iterative optimization methods or single-level optimization of generation or transmission expansion alone. Hence in this thesis we provide mixed complementarity problem formulations for transmission and generation expansion models with electricity market-clearing models. in this study we have considered co-optimization models formulated as bi-level programming problems as well as single-level mixed complementarity problems. in the upper level of the bi-level problem the system operator decides on the transmission expansion plans while anticipating the decisions in the lower level of the problem. The lower level problems present models of generation expansion and oligopolistic competition among power generators in the market where we examine perfect competition models to Cournot game among generators. This model is essentially an economic equilibrium problem for electricity markets that is defined by the optimality conditions that examine system operator’s and generators’ expansion behavior along with supply-demand balance in the market. These models will be handful for planning generation/transmission expansions and analyzing the relations between these expansions and the market outcomes. We have simulated market outcomes and expansion decisions in a 6-bus test system and a realistic Turkish electricity market under two different market structures (perfect competition and Nash-Cournot). Furthermore four different scenarios considering carbon costs and feed-in-tariffs (FiT) for Turkish electricity market for December 2020 are simulated and results are examined. Scenario considering both carbon costs and FiT have provided relatively better results in terms of social welfare.
A Comparative Study of Energy Models for Turkish Electricity Market Using Leap
(IEEE Computer Society, 2019) Massaga, Daniel Julius; Kirkil, Gökhan; Çelebi, Emre
Fossil fuel thermal power plants constitute a large part of the Turkish electricity generation capacity. Turkish government has been developing several energy policy documents to evaluate how various renewable energy sources of the country can be utilized optimally in the generation of electricity within the next 30 years. This study considers three scenarios in the transition to renewable energy for Turkey; the business as usual (BAU), energy conservation (EC) and renewable energy (REN) scenarios. EC scenario considers the use of energy-efficient appliances and imposing a carbon tax, whereas REN scenario considers increasing the share of the renewable energy sources as much as possible in the power generation mix. These scenarios were evaluated in terms of cost and environmental impact. The LEAP (Long-range Energy Alternatives Planning Model) was used in the research. The REN scenario has been shown to be the optimal energy policy option for Turkey in terms of cost and environmental impact.
Determination of Time-Of Prices in Electricity Markets Using Clustering Analyses
(Kadir Has Üniversitesi, 2016) Hussain, Mohsan; Çelebi, Emre
in this thesis a clustering analysis to determine the blocks (clusters) of hours for time-of-use (TOU) pricing scheme is proposed and different clustering algorithms are compared using different measures i.e. change in overall revenue mean absolute percent error and adjusted coefficient of determination (R2) from multiple linear regression analyses. Hourly electricity price and demand (load) data for two seasons (winter and summer) from Pennsylvania-New Jersey-Maryland (PJM) wholesale electricity market for 2014-2015 is used and based on detailed descriptive analyses and observations three blocks of hours (off-peak mid-peak and on-peak) are presented. in R software two clustering algorithms (agglomerative hierarchical and k-means) are employed and several clusters for summer and winter weekday hours are formed. The average of the hourly electricity prices in the same cluster for off-peak mid-peak and on-peak hours determines the TOU pricing scheme (hours in each cluster and prices for each clusters). These prices are compared to real-time pricing (RTP) rates in terms of change in overall revenue collected (price*load) and mean absolute percent error with respect to RTP rates. Finally in order to measure the significance of the TOU price and the demand relationship multiple linear regression analyses are performed. in the regression models dependent variable is the TOU price (or logarithm of it) and independent variables are the average load (or logarithm of it) of the TOU block of hours lagged TOU price and lagged TOU average load as well as categorical variables for off-peak mid-peak and on-peak hours for each TOU pricing scheme. Using Minitab software different regression models are built and adjusted R2 significance of regression coefficients and the significance of the overall model are computed. The significant models (with 95% confidence) are reported and the TOU clusters with higher adjusted R2 values are determined. Moreover in order to measure the autocorrelation effect Durbin-Watson statistics for each significant regression model are calculated and positive correlation among dependent and independent variables are reported. These analyses can be used by electricity market retailers distribution companies as well as regulatory bodies in determining TOU time blocks (clusters) and prices.
Electricity Market Equilibrium Models With Dynamic Demand Functions
(2013) Çelebi, Emre
Many electricity market models have either mostly ignored the demand response to changing prices (e.g. day-ahead models with mostly fixed demand) or at the other extreme they assumed that the full demand response occurred within one hour. Moreover the capital stock adjustment and the forward-looking nature of consumers are usually omitted. In this paper we propose variational inequality models for electricity markets with dynamic demand models where the intertemporal nature of consumption (i.e. the current consumption decision affects capital stock/habits and thus the future preferences and demand) is recognized. It is intended that the proposed models would develop a framework for electricity market equilibrium models that incorporate the dynamics of the demand side. © 2013 IEEE.
Citation - WoS: 6
Citation - Scopus: 6
Gamma-Robust electricity market equilibrium models with transmission and generation investments
(SPRINGER HEIDELBERG, 2021) Çelebi, Emre; Krebs, Vanessa; Schmidt, Martin
We consider uncertain robust electricity market equilibrium problems including transmission and generation investments. Electricity market equilibrium modeling has a long tradition but is, in most of the cases, applied in a deterministic setting in which all data of the model are known. Whereas there exist some literature on stochastic equilibrium problems, the field of robust equilibrium models is still in its infancy. We contribute to this new field of research by considering Gamma-robust electricity market equilibrium models on lossless DC networks with transmission and generation investments. We state the nominal market equilibrium problem as a mixed complementarity problem as well as its variational inequality and welfare optimization counterparts. For the latter, we then derive a Gamma-robust formulation and show that it is indeed the counterpart of a market equilibrium problem with robustified player problems. Finally, we present two case studies to gain insights into the general effects of robustification on electricity market models. In particular, our case studies reveal that the transmission system operator tends to act more risk-neutral in the robust setting, whereas generating firms clearly behave more risk-averse.
Citation - WoS: 2
Citation - Scopus: 2
Generation/Transmission Investment Planning Integrated With Market Equilibrium Models in Electricity Markets
(IEEE Computer Society, 2017) Çelebi, Emre
This paper introduces integrated models for transmission investments anticipating the generation investments and market-clearing equilibrium. Market-clearing models for deregulated electricity markets can inform decision makers on price signals formed in the competitive market other investor's and/or generator's behaviors underlying these price signals and new generation/transmission investment decisions. Bi-level programming problems are formed for this integrated models and reformulated by using mathematical programs with equilibrium constraints (MPEC). A simultaneous optimization model (as mixed complementarity problem-MCP) is proposed to compute the same equilibrium solution of the MPEC problem. The proposed MCP model is found to be computationally more efficient than the traditional MPEC reformulations on a simple 3-bus example. These models will be useful in planning generation/transmission investments and analyzing the relations among these investments and the market outcomes. © 2017 IEEE.
Market Price Simulations for Turkish Electricity Market Using Equilibrium Models
(Kadir Has Üniversitesi, 2014) Çakır, Hande; Çelebi, Emre
Electrical energy which is known as secondary energy sources is generated by the conversion of renewable energy sources to potential and chemical energy or is generated by variety processes of fossil fuels. Electricity is an important product in an economy and an important input for production of most of the goods and services. Electricity has unique properties such as non-storability and it has no full substitute and therefore the electricity industry is different from classical competitive industries. During the last decade new regulations and developments in the world have initiated various reform movements and a new action plan in Turkey to create a competitive market. The relevant legislation and procedures is created and specific markets are designed within this plan and vertically integrated structure of generation transmission and distribution activities are separated in this restructuring process. in this study we focus on many examples and applications in the world about electricity market equilibrium models. Since there is no market model applied in this way in Turkey it is created to simulate market prices by using GAMS software and adoption of market price simulations to Turkey's electricity markets are examined. Finally we have performed price-cost analyses and observe the welfare effects of different market structures. -- Abstract'tan.
Market-Clearing Simulations and Analyses for Turkish Electicity Market Market
(Kadir Has Üniversitesi, 2017) Şentürk Eker, Cansu; Çelebi, Emre
in this thesis current market structure of the Turkish electricity market which uses a uniform pricing system is analyzed and new market-clearing mechanisms (e.g. single or nodal pricing) are investigated for the market requirements. This has led to the development of different market-clearing models and market-price simulations that can be encountered in transition to a regional pricing model which provides market participants with greater transparency and simplicity in forecasting market outcomes. in the proposed models Turkish electricity market has been analyzed by using nine regional control areas (zones) pre-specified by Turkish Electricity Transmission Company (TETC). Based on Energy Exchange Ýstanbul transparency platform and TETC reports installed generation capacities are calculated for each region according to thirteen fuel types and seven different types of ownership. Different scenarios (e.g. seasonal peak mid-peak and off-peak) and data sets (e.g. capacity and load factors for weekdays and weekends as well as price-elastic linear demand function parameters for each region) are formed and different pricing models are formulated using a mixed complementarity problem (MCP) framework. Operation maintenance and fuel costs for each generation facility are obtained from international cost survey studies. The effects on social welfare and electricity price levels for the pricing models are examined in details using different market structures (e.g. perfectly competitive and Nash-Cournot). in MS EXCEL regional maps containing nine control areas of the transmission network are created and the results obtained from GAMS software are summarized using macros (e.g. visual basic for applications –VBA codes). in the literature such models appear for different regions and countries however it is a major shortcoming for Turkish electricity market. Hence the proposed models of this thesis will enable the analyses of decision-making process of market participants and their short/medium/long-term decisions as well as future investment plans and their impact on the market.
Citation - WoS: 8
Citation - Scopus: 8
Master Problem Approximations in Dantzig-Wolfe Decomposition of Variational Inequality Problems With Applications To Two Energy Market Models
(Pergamon-Elsevier Science Ltd, 2013) Çelebi, Emre; Fuller, David J.
In this paper a modification to Dantzig-Wolfe (DW) decomposition algorithm for variational inequality (VI) problems is considered to alleviate the computational burden and to facilitate model management and maintenance. As proposals from DW subproblems are accumulated in the DW master problem the solution time and memory requirements are increasing for the master problem. Approximation of the DW master problem solution significantly reduces the computational effort required to find the equilibrium. The approximate DW algorithm is applied to a time of use pricing model with realistic network constraints for the Ontario electricity market and to a two-region energy model for Canada. In addition to empirical analysis theoretical results for the convergence of the approximate DW algorithm are presented. (C) 2013 Elsevier Ltd. All rights reserved.
Models for Long-Term Electricity Price Forecasting for Turkish Electricity Market
(Kadir Has Üniversitesi, 2017) Özçelik, Sirun; Çelebi, Emre
in this study we have developed models for long-term electricity price forecasts for Turkish electricity market using multiple regression and time series forecasting methods. For the regression models we have firstly obtained the monthly data for demand weighted average of market-clearing electricity price (dependent variable) electricity demand hydro power production wind power production and population as well as yearly gross domestic product (GDP) and human development index (HDi) as independent variables for Turkey between December 2009 and September 2016 from the market operator's transparency database and other data sources. Secondly we have examined the effect of each of these independent variables on market-clearing electricity price and then by using time-series models long-term forecasts are obtained for all independent variables. Finally multiple-linear regression models are used to obtain forecasts for the monthly demand weighted average of electricity prices. in addition to multiple regression models several time series models such as exponential moving average (Holt-Winters model) seasonal autoregressive integrated moving average (SARiMA) and Artificial Neural Network (ANN) models are also developed. in setting up forecasting models R statistical packages and forecast tools as well as MATLAB (for ANN) are used. Long-term forecasts are made for the next 24 months starting from October 2016. Model results are evaluated according to mean absolute percentage error (MAPE) mean square error (MSE) and mean error (ME) which are commonly used error measures for evaluating forecasting results. We have found that on average around 8% of MAPE can be achieved through ANN method. This study would be useful for producers' investment decisions as well as market operator's long-term policy decisions.
Citation - WoS: 3
Citation - Scopus: 6
Reformulations of a Bilevel Model for Detection of Tacit Collusion in Deregulated Electricity Markets
(IEEE Computer Society, 2019) Çelebi, Emre; Şahin, Güvenç; Esmaeili Aliabadi, Danial
In this study, we consider a collusion model for competitive pool based electricity markets operated by an independent system operator (ISO), where it aims to prevent tacit collusion among generators. In order to determine the existence of tacit collusion in the market, we have employed the the game-Theoretic bilevel optimization model proposed by [1]. This model represents the market clearing mechanism, where generators determine their bids in order to maximize their profit while the system operator allocates power and determine locational electricity prices. The resulting optimization problem is a bilevel multi-criteria problem with non-linear terms, which is already complex and difficult to solve. We provide reformulations and linearization methods to obtain equivalent problems, e.g., a mathematical problem with equilibrium constraints (MPEC), a mixed integer non-linear problem (MINLP) and a mixed integer problem (MIP). A simple 6-bus system is used to test the rate of detection for collusive states for the reformulations and the results are presented. We have found that MIP models and reformulations detect strong collusive states. This model can guide ISOs in identifying and preventing cases of generator collusion.
Citation - WoS: 41
Citation - Scopus: 50
A 'regional Energy Hub' for Achieving a Low-Carbon Energy Transition
(Elsevier Sci Ltd, 2018) Güler, Burak; Çelebi, Emre; Nathwani, Jatin
The transition to a low-carbon energy economy will remain a cornerstone of national energy policies of countries committed to the climate change accord for decades to come. We think that transmission investment is one key policy instrument amongst other to help with this transition. We propose an enhanced role for investing in transmission capacity for inter-regional trade to allow effective fuel switching among countries through a physically connected market. We develop a conceptual framework of "Regional Energy Hubs" and propose a cost minimization model in support of a transmission investment strategy that integrates: (i) a key geopolitical parameter for countries that are geographically close in a region but under different political jurisdictions, judged as stable and receptive to firm trading arrangements, (ii) an economic parameter related to the fuel mix where the differences in a country's supply and demand characteristics are significant enough for allow mutual benefits to be realized through cost reduction, (iii) an environmental parameter linked to a country's carbon intensity that could benefit from the resources of a neighboring jurisdiction with lower intensities, and (iv) a financial parameter for each country within a region capable of attracting investment capital. A connected 'Regional Energy Hub' offers large economic and environmental benefit for transition to a low-carbon energy economy.
Risk Constrained Self-Scheduling for a Power Producer Using Power To Hydrogen Storage in Day-Ahead Markets
(Kadir Has Üniversitesi, 2019) Nur Küçük, Nida; Çelebi, Emre
In this thesis, optimal weekly self-schedule of a natural gas power plant with a hydrogen storage system is determined by using a stochastic model with risk constraints in a day-ahead electricity market. Different electricity price scenarios have been created for a weekly schedule where each scenario represents a certain month in a year. The risk associated with this scheduling decision is characterized by a conditional value at risk (CVaR) measure and a trade-off between this risk and operation profit is considered. The storage facility would allow electrical energy to be stored via hydrogen gas through electrolysis (power-to-gas, P2G, process) when the electricity prices are low or scheduled generation is more than required. On the other hand, stored hydrogen gas can be converted to electricity when the electricity prices are high or generation is less than required (gas-to-power, G2P, process). The self-scheduling model with risk trade-off has been formulated as a mixed integer linear program and a realistic case study that uses the proton exchange membrane (PEM) technology with eighty percent efficiency for electrolysis has been solved using GAMS program and CPLEX solver. This hybrid system case study shows that this risk constrained method helps to improve generation scheduling and increases the overall profit and trade-off with risk.
Citation - Scopus: 1
Turkey - Romania Subsea Transmission Cable Investment: Time for Reconsideration?
(2013) Guler, Burak; Fuller, David J.; Çelebi, Emre; Nathwani, Jatin S.
Transmission investment is important for integrating electricity markets operated by different countries/transmission system operators (TSOs). Turkey and Romania have proposed a transmission cable linking the transmission network between two countries under the Black Sea but this investment has been found infeasible due to the insufficient technical and financial benefits to the countries/TSOs. Now there may be a case for revisiting this project given emerging national and global policy frameworks leading to a 'shadow price' for carbon requiring decision analysis for investments to be guided by an explicit accounting of carbon-constraints. We propose a method that estimates the overall net benefit investing in this project by evaluating the project from the following perspectives: (1) economics where the energy resources of both countries are better utilized by evaluating the electricity supply and demand of each country (2) financial where the additional access to European electricity markets brings more trades in when the two promising markets are physically coupled (3) environmental where the effect of emission constraints are introduced. © 2013 IEEE.
Citation - WoS: 35
Citation - Scopus: 41
Turkish Public Preferences for Energy
(Elsevier Science, 2018) Ediger, Volkan S.; Kirkil, Gökhan; Çelebi, Emre; Ucal, Meltem Şengün; Kentmen-Cin, Çiğdem
Public concern over energy supplies prices sustainability and efficiency has emerged as a major issue around the world. Yet most of what we know regarding public opinion on energy comes from North America and Europe. This paper presents the results from the 2016 Turkish Public Preferences for Energy Survey which included 1204 respondents and examined Turkish residents' household energy consumption energy policy preferences and environmental concerns. The main findings were that Turkish citizens consider natural gas and electricity highly expensive view dependence on imported energy as Turkey's most pressing energy challenge and recognize the problem of climate change. This lends public support for wind and solar power but at the same time energy issues and the environment policies of political parties do not affect voting choices and political preferences.
Türkiye Elektrik Piyasası İçin Ekonomik Denge Modelleri: Piyasa Denge Modelleri İle Üretim/iletim Yatırım Modellerinin Bütünleştirilmesi
(2018) Uyan, Zeki; Eker, Cansu Şentürk; Çelebi, Emre
Dünya ve Türkiye elektrik piyasalarındaki yeniden yapılanma (ve de serbestleşme) sürecinde, tekelci ve dikey yapıdaki kamu elektrik şirketi yerini özel üretim/dağıtım şirketleri ile düzenleyici ve denetleyici üst kurumların piyasa kurallarını belirlediği ve bağımsız sistem işletmecisinin organize ettiği çok oyunculu yeni bir piyasa yapısına bırakmıştır. Bu bağlamda, Türkiye elektrik piyasasında yeni üretim/iletim kapasite yatırım kararlarını, rekabetçi piyasada oluşacak fiyat sinyallerini ve fiyat sinyalinin altında yatan diğer yatırımcı ve/veya üreticilerin davranışlarını, yakıt maliyetleri ve talep artışı gibi arz-talep dinamiğine bağlı belirsizlikleri dikkate alabilen ekonomik denge modelleri ile tahminler ve planlamalar yapabilmek için piyasa-takas veya piyasa fiyatı benzetim modellerine ihtiyaç duyulmaktadır. Bunun yanısıra, piyasa modelleri ile planlama ve geleceğe dönük kestirimler yapılabileceğinden, yatırım kararları ile bütünleşik bu tarz modellere (şirketlerin ve tüketicilerin piyasadaki davranışlarını, denetleyici ve düzenleyici kurumun piyasa izleme/denetleme faaliyetlerini ve sistem işletmecisinin piyasayı ve sistemi gözlemleme ve işletme görevlerini analiz edebilecek) ihtiyaç kaçınılmazdır. Bu projede, Türkiye elektrik piyasası için piyasa-takas/piyasa fiyatı benzetim modeli oluşturulmuş ve bu modele üretim/iletim yatırım modelleri eklenmiştir. Bu bağlamda, yatırımcılar için büyük önem arz eden çok çeşitli etkenlerin (örneğin piyasa gücü, iletim kısıtlılıkları, üretimdeki belirsizlikler, talep tepkisi ve belirsizlikleri gibi) piyasa fiyatı sinyali üzerindeki etkileri simüle edilmiştir. Ayrıca önerilen bütünleşik modeller, hem geleceğe dönük yatırım planları açısından hem de bunların piyasaya etkileri ve piyasa oyuncularının karar verme süreçlerindeki sonuçları bakımından oldukça faydalı sonuçlar sunmaktadır. Bu projede geliştirilen bütünleşik modeller tek-seviyeli ve iki-seviyeli olarak formüle edilmiş ve oldukça genel koşullar altında bu modellerin tamamlayıcılık problemleri kullanılarak etkin bir şekilde çözülebildiği görülmüştür. Bunun yanısıra ikili tamsayı kısıtlı karışık tamamlayıcılık problemlerinin bu yapı altında çözülebildiği bir test sistemi üzerinde gösterilmiştir. Bu modellerin Türkiye elektrik piyasasındaki uygulamalarından ise etkin bir politika analiz aracı olarak kullanılabileceği ve çeşitli senaryolar ile piyasa dinamiklerini analiz edebileceği görülmüştür.