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In this paper, we formulate and solve a real life coal blending problem using a Column Generation Approach. The objective of the model is to prescribe optimal mixes of coal to produce coke. The problem is formulated as a mixed integer program. It involves various types of constraints arising from technical considerations of the blending process. The model also incorporates nonlinear constraints. It results in a large-scale problem that cannot be solved by classical operations research methods. Defining three heuristic methods based on column generation techniques, this paper proposes reasonable solutions for the industry. [ABSTRACT FROM AUTHOR]

The extreme volatility of electricity prices makes their financial derivatives important instruments for asset managers. Even if the volume of derivative contracts traded on Power Exchanges has been growing since the inception of the restructuring of the sector, electricity remains considerably less liquid than other commodity markets. This paper assesses the effect of limited liquidity in power exchanges using an equilibrium model where agents cannot hedge up to their desired level. Mathematically, the problem is formulated as a two stage stochastic Generalized Nash Equilibrium with possibly multiple equilibria. Computing a large panel of solutions, we show how the risk premium and players profits are affected by illiquidity. We also show that the illiquidity in the FTR market affects the trades in the electricity futures market. [ABSTRACT FROM AUTHOR]

This paper addresses a problem that is typical of multi-period capacity expansion equilibrium models: plants or sectors have different risk exposures that may warrant different costs of capital. The paper examines modifications of a capacity expansion model interpreted in equilibrium terms to account for asset-specific costs of capital. [ABSTRACT FROM AUTHOR]

We take advantage of the interpretation of stochastic capacity expansion problems as stochastic equilibrium models for assessing the risk exposure of new equipment in a competitive electricity economy. We develop our analysis on a standard multistage generation capacity expansion problem. We focus on the formulation with nonanticipativity constraints and show that their dual variables can be interpreted as the net margin accruing to plants in the different states of the world. We then propose a procedure to estimate the distribution of the Lagrange multipliers of the nonanticipativity constraints associated with first stage decisions; this gives us the distribution of the discounted cash flow of profitable plants in that stage. [ABSTRACT FROM AUTHOR]

'Market Coupling' is currently seen as the most advanced market design in the restructuring of the European electricity market. Market Coupling, by construction, introduces what is generally referred to as an incomplete market: it leaves several constraints out of the market and hence avoids pricing them. This may or may not have important consequences in practice depending on the case on hand. Quasi-Variational Inequality problems and the associated Generalized Nash Equilibrium can be used for representing incomplete markets. Recent papers propose methods for finding a set of solutions of Quasi-Variational Inequality problems. We apply one of these methods to a subproblem of market coupling namely the coordination of counter-trading. This problem is an illustration of a more general question encountered, for instance, in hierarchical planning in production management. We first discuss the economic interpretation of the Quasi-Variational Inequality problem. We then apply the algorithmic approach to a set of stylized case studies in order to illustrate the impact of different organizations of counter-trading. The paper emphasizes the structuring of the problem. A companion paper considers the full problem of Market Coupling and counter-trading and presents a more extensive numerical analysis. [ABSTRACT FROM AUTHOR]

Although there are mechanisms to control market power in the spot market, withholding investments can still increase profits and hamper adequate capacity expansion. We examine the effect on investment of one suggested approach to reducing market power, contracting longer term. We construct a stylized model of an energy-only market where two firms, each specializing in one technology, invest in a first stage, contract part of their production in the second stage and sell the rest in the spot market in the third stage. We compare this model to one of an energy-only market having two stages, investment and a spot market. We find cases where the contracts change neither capacity nor peak prices, where the foreclosing effect of one player blocking the other from contracts markets increases investments and reduces prices, and where the opportunity to foreclose the market can incentivize one firm to lower its investment and increase its pricing power to the detriment of consumers. The model relies on the simplest possible assumptions of imperfect competition (subgame perfect equilibria with Cournot agents). We illustrate the different outcomes in a numerical example with two load steps (peak and off-peak) where we change one parameter, the height of the off-peak time segment. We find cases with increased and decreased capacity as well as no change in capacity. Since there is no general characterization of the consequences of contracts in this simple example, there can be no characterization in more complicated models that contain the market structures included here, and regulators or competition authorities cannot rely on contracts to induce sufficient capacity expansion by reducing market power. One other market mechanism that has been proposed to induce investment, a capacity auction with predetermined capacity requirements, is a potential alternative to limit market power that deserves further exploration to determine the extent to which it can provide an adequate incentive to invest in the presence of market power. [ABSTRACT FROM AUTHOR]

Cross-border trade remains a contentious issue in the restructuring of the European electricity market. This paper analyzes the cross-border trade problem through a set of models that represent different degrees of coordination both between the energy and the transmission markets and among national Transmission System Operators (TSOs). We first present a nodal price-like organization of the system, where Power Exchanges (PXs) and Transmission System Operators are integrated to operate the energy and transmission markets. This system is not implemented in Europe but its success elsewhere makes it the natural reference for the study. We then move to a more realistic representation of the European electricity market based on the so-called market coupling design where energy and transmission are operated separately by PXs and TSOs. We consider different degrees of coordination of the national TSOs' activities to assess the range of inefficiencies that the lack of integration can lead to. The paper supposes price taking agents and hence leaves aside the incentive to game the system induced by zonal systems. [ABSTRACT FROM AUTHOR]

We cast models of the generation capacity expansion type formally developed for the monopoly regime into equilibrium models better adapted for a competitive environment. We focus on some of the risks faced today by investors in generation capacity and thus pose the problem as a stochastic equilibrium model. We illustrate the approach on the problem of the incentive to invest. Agents can be risk neutral or risk averse. We model risk aversion through the CVaR of plants' profit. The CVaR induces risk-adjusted probabilities according to which investors value their plants. The model is formulated as a complementarity problem (including the CVaR valuation of investments). An illustration is provided on a small problem that captures several features of today's electricity world: a choice often restricted to coal and gas units, a peaky load curve because of wind penetration, uncertain fuel prices, and an evolving carbon market. We assess the potential of the approach by comparing energy-only and capacity market organizations in this risky environment. Our results can be summarized as follows: a deterministic analysis overlooks some changes of capacity structure induced by risk, whether in the capacity market or energy-only organizations. The risk-neutral analysis also misses a shift towards less capital-intensive technologies that may result from risk aversion. Last, risk aversion also increases the shortage of capacity compared to the risk-neutral view in the energy-only market when the price cap is low. This may have a dramatic impact on the bill to the final consumer. The approach relies on mathematical programming techniques and can be extended to full-size problems. The results are illustrative and may deserve more investigation. [ABSTRACT FROM AUTHOR]

Allaz and Vila made the seminal contribution that forward contracts mitigate market power on the spot market. This result is widely quoted and elaborated in studies of restructured power markets, where generators can potentially exploit the special characteristics of this industry in order to extract higher prices. Allaz-Vila established their result under the assumption that the production capacities of the players are infinite. We show that the Allaz-Vila result does not hold when capacities are endogenous and constraining generation. Specifically, a forward market can enhance or mitigate market power when capacities are endogenous and demand is unknown at the time of investment. We also show that forward markets do not mitigate market power when capacities are endogenous and demand is known at the time of investment. Our results complement other work that shows that forward markets systematically enhance market power in some symmetric capacity-constrained markets. [ABSTRACT FROM AUTHOR]

The inception of the emission trading scheme in Europe has contributed to power price increases. Energy intensive industries have reacted by arguing that this may affect their competitiveness and will induce them to leave Europe. Taking up a proposal of these industrial sectors, we explore the possible application of special contracts, where electricity is sold at average generation cost to mitigate the impact of CO2 cost on power prices. The model supposes fixed generation capacities. We first consider a reference model representing a perfectly competitive market where all consumers (industries and the rest of the market) are price-takers and buy electricity at short-run marginal cost. We then change the market design by assuming that energy intensive industries pay power either at a regional or at a zonal average cost price. The analysis is conducted with simulation models applied to the Central Western European power market. The models are implemented in GAMSIPATH. [ABSTRACT FROM AUTHOR]

We consider three models of investments in generation capacity in restructured electricity systems that differ with respect to their underlying economic assumptions. The first model assumes a perfect, competitive equilibrium. It is very similar to the traditional capacity expansion models even if its economic interpretation is different. The second model (open-loop Cournot game) extends the Cournot model to include investments in new generation capacities. This model can be interpreted as describing investments in an oligopolistic market where capacity is simultaneously built and sold in long-term contracts when there is no spot market. The third model (closed-loop Cournot game) separates the investment and sales decision with investment in the first stage and sales in the second stage--that is, a spot market. This two-stage game corresponds to investments in merchant plants where the first-stage equilibrium problem is solved subject to equilibrium constraints. We show that despite some important differences, the open- and closed-loop games share many properties. One of the important results is that the prices and quantities produced in the closed-loop game, when the solution exists, fall between the prices and quantities in the open-loop game and the competitive equilibrium. [ABSTRACT FROM AUTHOR]

Abstract: An efficient congestion management system is a necessary condition to remove obstacles to the cross-border trade of electricity in Europe and hence to move towards an internal electricity market. Locational marginal pricing (LMP) is progressively becoming the benchmark of congestion management in the United States. It is conceptually simple, compatible with basic economic theory and physical realities, and effective in practice. Proposals for congestion management in Europe depart in several ways from this benchmark. We discuss these proposals and illustrate some of their inefficiencies. A special emphasis is placed on the restrictions to trade implied by the implementation of zonal approaches. [Copyright &y& Elsevier]

The paper extends our previous analysis of market incompleteness to the case where there exist both a forward and real time market. The discussion is conducted with reference to a two-stage framework commonly used in stochastic programming and finance, but also familiar to the power industry. The paper considers two market designs. The first organization assumes that physical transmission services are auctioned in the forward market. The second organization supposes a financial market of transmission services. We recover the known perfect hedging property of nodal pricing and show that the flowgate model does not share this property. A standard proposition in finance is that market completeness requires that the number of tradable instruments is equal to or exceeds the number of risk factors. We show that none of the nodal or flowgate models satisfy this property. Other instruments, of the option type, should thus be introduced in these systems in order to better trade risk and complete the market. [ABSTRACT FROM AUTHOR]

The paper analyses various proposals for the organization of regional electricity transmission in terms of the market incompleteness that they may implicitly assume. Elementary notions of variational inequalities constitute the analytical tool used throughout the paper. The discussion is conducted with reference to the flowgate debate in the US and European proposals for the organization of cross border electricity trade. This first part of the paper discusses market incompleteness in the forward (day ahead) market. The main results can be summarized as follows. An energy market without a market for transmission services is incomplete and hence inefficient. The nodal and flowgate models complete the market when one does not consider contingencies. One can define a notion of transmission capacity (called an extended flowgate) by aggregating line capacities using spot prices. This transmission capacity completes the market and reduces the number of necessary flowgates (possibly to one). But these extended flowgates have variable capacities. As in the case of the nodal model, extended flowgates can accommodate contingencies in the forward market. [ABSTRACT FROM AUTHOR]

Different equilibrium concepts have been proposed by various authors (Schweppe et al., Hogan et al., Chao and Peck, Wu et al.) to analyse competitive electricity systems. We establish correspondences between these different models through a single framework and provide additional interpretations of these equilibrium concepts. This unifying conceptual view also provides a computationally feasible approach to simulate the market. It also opens the way to the modeling of some imperfect markets. [ABSTRACT FROM AUTHOR]

The problem of distributing gas through a network of pipelines is formulated as a cost minimization subject to nonlinear flow-pressure relations, material balances, and pressure bounds. The solution method is based on piecewise linear approximations of the nonlinear flow-pressure relations. The approximated problem is solved by an extension of the Simplex method. The solution method is tested on real-world data and compared with alternative solution methods. [ABSTRACT FROM AUTHOR]

An oligopoly with spatially dispersed generators and consumers and with multi-period demand is modeled in this paper. The producers are assumed to behave in a Cournot manner with regulated transmission prices. A (generalized) Nash equilibrium is sought. The story of the game is as follows. Each generator takes its rivals' output (generation, supply, and flows) and the prices for transmission services as fixed when it decides upon its output to maximize its profit; the transmission firm takes the quantities of transmission services demanded by the generators as fixed when it determines the transmission prices according to certain regulatory rules. An equilibrium of the model is a set of generation output at which no generator will obtain more profit if it unilaterally modifies its output from this set, and a set of transmission prices satisfying certain regulatory requirements. A variational inequality approach is used for computing the equilibria of the model. Using the same approach, two variants of the model, respectively based on average-cost and marginal-cost pricing for transmission services, are also formulated. This model is applied to simulate a long-run electricity market where transmission prices are regulated. [ABSTRACT FROM AUTHOR]

Discusses the decision process driving the reorganization of the electricity and gas systems in the European Community. Common rules in the reorganization of the markets; Approach to used in restructuring; Impact of industrial economics and computation of economic equilibrium on the industries; Applications of the Cournot and Bertrand paradigms in ex ante analysis of the markets.

The article discusses various reports published within the issue, including a case study of distributed electricity generation in Australia, a definition of distributed resources (DR) planning and the use of DR in risk management due to demand uncertainty.