Existence & uniqueness of consistent conjectural variation equilibrium in electricity markets

The real electricity markets are usually oligopoly, where market suppliers (generators) will have some market power and can adopt strategic bidding strategies for maximum profits. Generally, the game-theory based methods are the natural way to analyze the market equilibrium and study the strategic behaviors. As a widely studied method in game theory, the conjecture variation technique is reported to model the strategic behavior in deregulated electricity markets recently. Unfortunately, the conjecture variation models have been criticized for the drawback of logical inconsistence and abundant equilibria. Aim for this, the existence and uniqueness of consistent conjectural variation equilibrium in the electricity markets are investigated. Due to some good characteristics of electricity markets and using an infinite horizon optimization model, it is shown that the consistent conjecture variation will satisfy a coupled nonlinear equation system and there is only one equilibrium. © 2005 IEEE.published_or_final_versio

Information requirements for strategic decision making: energy market

Over the last two decades, the electricity sector has been involved in a challenging restructuring process in which the vertical integrated structure (monopoly) is being replaced by a horizontal set of companies. The growing supply of electricity, flowing in response to free market pricing at the wellhead, led to increased competition. In the new framework of deregulation, what characterizes the electric industry is a commodity wholesale electricity marketplace. This new environment has drastically changed the objective of electricity producing companies. In the vertical integrated industry, utilities were forced to meet all the demand from customers living in a certain region at fixed rates. Then, the operation of the Generation Companies (GENCOs) was centralized and a single decision maker allocated the energy services by minimizing total production costs. Nowadays, GENCOs are involved not only in the electricity market but also in additional markets such as fuel markets or environmental markets. A gas or coal producer may have fuel contracts that define the production limit over a time horizon. Therefore, producers must observe this price levels in these other markets. This is a lesson we learned from the Electricity Crisis in California. The Californian market\u27s collapse was not the result of market decentralization but it was triggered by other decisions, such as high natural gas prices, with a direct impact in the supply-demand chain. This dissertation supports generation asset business decisions -from fuel supply concerns to wholesale trading in energy and ancillary services. The forces influencing the value chain are changing rapidly, and can become highly controversial. Through this report, the author brings an integrated and objective perspective, providing a forum to identify and address common planning and operational needs. The purpose of this dissertation is to present theories and ideas that can be applied directly in algorithms to make GENCOs decisions more efficient. This will decompose the problem into independent subproblems for each time interval. This is preferred because building a complete model in one time is practically impossible. The diverse scope of this report is unified by the importance of each topic to understanding or enhancing the profitability of generation assets. Studies of top strategic issues will assess directly the promise and limits to profitability of energy trading. Studies of ancillary services will permit companies to realistically gauge the profitability of different services, and develop bidding strategies tuned to competitive markets

Oligopolistic and oligopsonistic bilateral electricity market modeling using hierarchical conjectural variation equilibrium method

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel UniversityAn electricity market is very complex and different in its nature, when compared to other commodity markets. The introduction of competition and restructuring in global electricity markets brought more complexity and major changes in terms of governance, ownership and technical and market operations. In a liberalized electricity market, all market participants are responsible for their own decisions; therefore, all the participants are trying to make profit by participating in electricity trading. There are different types of electricity market, and in this research a bilateral electricity market has been specifically considered. This thesis not only contributes with regard to the reviewing UK electricity market as an example of a bilateral electricity market with more than 97% of long-term bilateral trading, but also proposes a dual aspect point of view with regard to the bilateral electricity market by splitting the generation and supply sides of the wholesale market. This research aims at maximizing the market participants’ profits and finds the equilibrium point of the bilateral market; hence, various methods such as equilibrium models have been reviewed with regard to management of the risks (e.g. technical and financial risks) of participating in the electricity market. This research proposes a novel Conjectural Variation Equilibrium (CVE) model for bilateral electricity markets, to reduce the market participants’ exposure to risks and maximize the profits. Hence, generation companies’ behaviors and strategies in an imperfect bilateral market environment, oligopoly, have been investigated by applying the CVE method. By looking at the bilateral market from an alternative aspect, the supply companies’ behaviors in an oligopsony environment have also been taken into consideration. At the final stage of this research, the ‘matching’ of both quantity and price between oligopolistic and oligopsonistic markets has been obtained through a novel-coordinating algorithm that includes CVE model iterations of both markets. Such matching can be achieved by adopting a hierarchical optimization approach, using the Matlab Patternsearch optimization algorithm, which acts as a virtual broker to find the equilibrium point of both markets. Index Terms-- Bilateral electricity market, Oligopolistic market, Oligopsonistic market, Conjectural Variation Equilibrium method, Patternsearch optimization, Game theory, Hierarchical optimization metho

Analysis of futures and spot electricity markets under risk aversion.

We analyze the procurement problem in the electricity supply chain, focusing on the interaction between futures and spot prices. The supply chain network analyzed in our study includes risk-averse generators and retailers, both with the ability to use conditional value at risk (CV@R) in their decision processes. In this supply chain, the futures price is computed to clear the futures market, without imposing the constraint that the expected spot price equals the futures price. As major methodological contributions: we compute the Nash equilibrium of the problem using CV@R and considering conjectural variations; we derive analytical relationships between the futures and the spot market outcomes and study the implications of demand and marginal cost uncertainty, as well as the level of the players' risk aversion, on market equilibrium; we introduce the concept of risk-adjusted expectation to derive the futures market price as a function of the players' expected losses or profits in the spot market; and we use consistent spot and wholesale price derivatives to calculate the players' reaction functions. Finally, we illustrate our model with several numerical examples in the context of the Spanish electricity market, studying how the shape of the forward curve and the relationship between spot and futures prices depend on seasonality, risk aversion, generators' market power, and hydrological resources. Surprisingly we observed that risk aversion increases the profit and reduces firms' risk, and that the consumer utility is higher in the scenarios in which retailers behave a la Cournot in the wholesale market

Analysis of collusion and competition in electricity markets using an agent-based approach

As a result of liberalization, deregulated electricity markets were formed to provide affordable electricity for consumers through promoting competition. Although the new market is expected to serve this purpose, even the earliest deregulated electricity markets are prone to threats that may disrupt the competition. While the independent system operator, responsible for administering the electricity markets, aims to provide the consumer with the lowest possible electricity price, lack of competition may increase prices. We consider the effect of three major factors hand-in-hand on that may affect the level of competition in the market: the independent system operator’s market-clearing mechanism as a strategic choice, strategic bidding behavior of generation companies and the transmission network

Strategic Bidding of Offer Curves: An Agent-Based Approach to Exploring Supply Curve Equilibria

We model a market in which suppliers bid step-function offer curves using agent-based modeling. Our model is an abstraction of electricity markets where step-function offer curves are given to an independent system operator that manages the auctions in electricity markets. Positing an elementary and computationally accessible learning model, Probe and Adjust, we present analytic results that characterize both the behavior of the learning model and the properties of step-function equilibria. Thus, we have developed a framework for validating agent-based models prior to using them in situations that are too complicated to be analyzed using traditional economic theory. In addition, we demonstrate computationally that, by using alternative policies, even simple agents can achieve monopoly rewards for themselves by pursuing more industry-oriented strategies. This raises the issue of how participants in oligopolistic markets actually behave

Supply function equilibrium analysis for electricity markets

The research presented in this Thesis investigates the strategic behaviour of generating firms in bid-based electricity pool markets and the effects of control methods and network features on the electricity market outcome by utilising the AC network model to represent the electric grid. A market equilibrium algorithm has been implemented to represent the bi-level market problem for social welfare maximization from the system operator and utility assets optimisation from the strategic market participants, based on the primal-dual interior point method. The strategic interactions in the market are modelled using supply function equilibrium theory and the optimum strategies are determined by parameterization of the marginal cost functions of the generating units. The AC power network model explicitly represents the active and reactive power flows and various network components and control functions. The market analysis examines the relation between market power and AC networks, while the different parameterization methods for the supply function bids are also investigated. The first part of the market analysis focuses on the effects of particular characteristics of the AC network on the interactions between the strategic generating firms, which directly affect the electricity market outcome. In particular, the examined topics include the impact of transformer tap-ratio control, reactive power control, different locations for a new entry’s generating unit in the system, and introduction of photovoltaic solar power production in the pool market by considering its dependencyon the applied solar irradiance. The observations on the numerical results have shown that their impact on the market is significant and the employment of AC network representation is required for reliable market outcome predictions and for a better understanding of the strategic behaviour as it depends on the topology of the system. The analysis that examines the supply function parameterizations has shown that the resulting market solutions from the different parameterization methods can be very similar or differ substantially, depending on the presence and level of network congestion and on the size and complexity of the examined system. Furthermore, the convergence performance of the implemented market algorithm has been examined and proven to exhibit superior computational efficiency, being able to provide market solutions for large complex AC systems with multiple asymmetric firms, providing the opportunity for applications on practical electricity markets

"On a Level with Dentists?" Reflections on the Evolution of Industrial Organization

This essay provides a brief overview of the evolution of the field of industrial organization from its emergence to the present, and it offers some observations about the present state of the field. While there has been considerable progress in industrial organization over time, its uphill path has not been straight

Investigation of the impact of demand elasticity and system constraints on electricity market using extended Cournot approach

Includes bibliographical referencesIn today's electricity supply industry, demand side participation is considered an important factor that can influence the market performance and output effectively. Demand elasticity shows the sensitivity of demand side to the market price, and thus can provide potential adjustment of demand in the market. The purpose of this research is to study the impact of demand elasticity on power producers 'market competition output. An analytical model, called "Extended Cournot model" is developed in this thesis based on the classical Cournot model. Through the integration with conjectural variation model, in which power producers consider both the generation and price level, the extended Cournot model can analyze electricity market results under the conditions of different constraints. In the classical Nash Cournot model, capacity withdrawal exists in most cases especially when transmission constraint occurs. In contrast, the newly developed analytical model ensures that demand is always satisfied at all time. Demand elasticity is incorporated directly into the market results calculation instead of using the market clearing price. This approach enables the load demand to directly obtain the market results by tuning its demand elasticity. The intention is to show that demand side should be more encouraged to participate in the market competition. In the classical economic dispatch, the load demand is highly inelastic. From the load curve, there is only a change of physical volume of demand. The demand responsiveness, which is represented by demand elasticity, has been understated. In this thesis, the hypothesis is that demand elasticity and system constraint have critical influence on the power producers' competition results in terms of market clearing price, individual output and profit. Load demand can make use of demand elasticity to affect its final payment to the market. Such ability is expected to be limited in the case where system constraints, i.e. generation limits and transmission limits, exist. For simplicity, a small network and number of power producers are used in this thesis to investigate the effectiveness of the Extended Cournot model. However, this model can be applied to more complex networks with different market environments