Equilibrium Predictions in Wholesale Electricity Markets

We review supply function equilibrium models and their predictions on market outcomes in the wholesale electricity auctions. We discuss how observable market characteristics such as capacity constraints, number of power suppliers, load distribution and auction format affect the behavior of suppliers and performance of the market. We specifically focus on the possible market power exerted by pivotal suppliers and the comparison between discriminatory and uniform-price auctions. We also describe capacity investment behavior of electricity producers in the restructured industry.Electricity markets; Supply function equilibrium; Markov perfect equilibrium; electricity auctions; pivotal suppliers; capacity investment.

Two-Dimensional Product Differentiation Under Duopoly: An Application to Product and Service Reliability

Under oligopoly firms are often observed to specialise their production, with some firms producing highly reliable output and offering good warranty deals, while others produce less reliable output and offer less attractive warranties, but charge a lower price. This paper develops an approach to product/service reliability which provides an alternative to the conventional analysis based on the characteristics approach. The model of this paper defines reliability as the objective probability of product failure, not as a characteristic of individual goods. Reliability, thus defined, is treated as a choice variable of the firm, and consumers’ preferences are partially endogenised. This approach to reliability is incorporated into a duopoly model which explains the phenomenon of specialisation described above. The model is applicable to the markets for consumer durables, some intermediate goods and some services.Reliability, duopoly.

The Question of Generation Adequacy in Liberalised Electricity Markets

This paper presents an overview of the reasons why unregulated markets for the production of electricity cannot be expected to invest sufficiently in generation capacity on a continuous basis. Although it can be shown that periodic price spikes should provide generation companies with sufficient investment incentives in theory, there are a number of probable causes of market failure. A likely result is the development of investment cycles that may affect the adequacy of capacity. The experience in California shows the great social costs associated with an episode of scarce generation capacity. Another disadvantage is that generation companies can manipulate price spikes. This would result in large transfers of income from consumers to producers and reduce the operational reliability of electricity supply during these price spikes. We end this paper by outlining several methods that have been proposed to stabilise the market, which provide better incentives to generation companies and consumers alike.Generation adequacy, Liberalised electricity market

A game theoretic model for generation capacity adequacy in electricity markets: A comparison between investment incentive mechanisms

Working Paper GATE 2009-05In this paper we study the problem of long-term capacity adequacy in electricity markets. We implement a dynamic model in which operators compete for investment and electricity production under imperfect Cournot competition. The main aim of this work is tocompare three investment incentive mechanisms: reliability options, forward capacity market - which are both market-based - and capacity payments. Apart from the oligopoly case, we also analyze collusion and monopoly cases. Stochastic dynamic programming is used to deal with the stochastic environment of the market (future demand) and mixed complementarityproblem formulation is employed to find a solution to this game. The main finding of this study is that market-based mechanisms would be the most cost-efficient mechanism for assuring long-term system adequacy and encouraging earlier and adequate new investments in the system. Moreover, generators would exert market power when introducing capacity payments. Finally, compared with a Cournot oligopoly, collusion and monopolistic situations lead to more installed capacities with market-based mechanisms and increase end-users' payments

Three Essays on Decision Making under Uncertainty in Electric Power Systems

This thesis consists of three essays, discussing three different but connected problems on decision making under uncertainty in electricpower systems.The first essay uses a system model to examine how various factors affect the market price of electricity, and decomposes the price toquantitatively evaluate the contributions of individual factors as well as their interactions. Sensitivity analysis results from a parametric quadratic program are applied in the computation.The second essay formulates the well studied security constrained economic dispatch (SCED) problem as a Markov decision process model,where the action space is a polyhedron defined by linear generation and transmission constraints. Such a model enables the decision maker to accurately evaluate the impact of a dispatch decision to the entire future operation of the electric power system.The third essay examines the effect of demand and supply side uncertainties on the exercise of market power. Solutions under Bertrand, Cournot, and linear supply function equilibrium (LSFE)models are derived and compared.The three problems studied in the essays are a unique representation of different levels of the decision making process in a sophisticated deregulated electric power system, using techniques from both mathematical programming and probability/statistics

The Elmar model: output and capacity in imperfectly competitive electricity markets

With the ongoing liberalization and integration of European energy markets and the increasing worries about security of supply, the need for thorough economic analysis of electricity markets is growing. Elmar is a model for the European electricity market, taking into account imperfect competition through conjectural variations, as well as imperfect international competition due to import capacity restrictions. The model distinguishes between competition on the output market and competition in capacity investments. We find that the least competitive of these determines wholesale prices.

A Review of the Monitoring of Market Power The Possible Roles of TSOs in Monitoring for Market Power Issues in Congested Transmission Systems

The paper surveys the literature and publicly available information on market power monitoring in electricity wholesale markets. After briefly reviewing definitions, strategies and methods of mitigating market power we examine the various methods of detecting market power that have been employed by academics and market monitors/regulators. These techniques include structural and behavioural indices and analysis as well as various simulation approaches. The applications of these tools range from spot market mitigation and congestion management through to long-term market design assessment and merger decisions. Various market-power monitoring units already track market behaviour and produce indices. Our survey shows that these units collect a large amount of data from various market participants and we identify the crucial role of the transmission system operators with their access to dispatch and system information. Easily accessible and comprehensive data supports effective market power monitoring and facilitates market design evaluation. The discretion required for effective market monitoring is facilitated by institutional independence.Electricity, liberalisation, market power, regulation

A game theoretic model for generation capacity adequacy in electricity markets: A comparison between investment incentive mechanisms

In this paper we study the problem of long-term capacity adequacy in electricity markets. We implement a dynamic model in which operators compete for investment and electricity production under imperfect Cournot competition. The main aim of this work is tocompare three investment incentive mechanisms: reliability options, forward capacity market - which are both market-based - and capacity payments. Apart from the oligopoly case, we also analyze collusion and monopoly cases. Stochastic dynamic programming is used to deal with the stochastic environment of the market (future demand) and mixed complementarityproblem formulation is employed to find a solution to this game. The main finding of this study is that market-based mechanisms would be the most cost-efficient mechanism for assuring long-term system adequacy and encouraging earlier and adequate new investments in the system. Moreover, generators would exert market power when introducing capacity payments. Finally, compared with a Cournot oligopoly, collusion and monopolistic situations lead to more installed capacities with market-based mechanisms and increase end-users' payments.Electricity markets; capacity adequacy; dynamic programming; Nash-Cournot model; mixed complementarity problem

Restructuring Electricity Markets when Demand is Uncertain: Effects on Capacity Investments, Prices and Welfare

We examine the effects of restructuring electricity markets on capacity investments, retail prices and welfare when demand is uncertain. We study the following market configurations: (i) integrated monopoly, (ii) integrated duopoly with wholesale trade, and (iii) separated duopoly with wholesale trade. Assuming that wholesale prices can react to changes in retail prices (but not vice versa), we find that generators install sufficient capacity to serve retail demand in each market configuration, thus avoiding blackouts. Furthermore, aggregate capacity levels and retail prices are such that the separated (integrated) duopoly with wholesale trade performs best (worst) in terms of welfare.electricity; investments; generating capacities; vertical integration; monopoly and competition