In the first chapter, we propose a new method for modeling competition in electricity spot markets, namely, by approximating the supply functions of the competitors with cubic splines. We argue that this method is preferable to approximation by linear or piecewise-affine functions, which have been the main approaches to date. We apply our method to the firms competing in the Texas market. We also show that, more often than not, we will observe that the marginal revenue functions of the firms will have increasing segments which may lead to multiple profit-maximizing optima for a firm. In the second chapter, we model the effects of forward contracting on power prices in wholesale electricity markets. In contrast to most of the previous literature, we explicitly model power retailers, and introduce risk aversion. As expected, increasing the number of players have pro-competitive effects on the spot price of electricity. We also find that as the generators bid more competitively, spot and forward prices converge. Our model also captures the effects of level and variability of power demand on the players' contracting decisions. In the final chapter, we depart from equilibrium approach and utilizing agent-based modeling, analyze the effects of increased power demand price sensitivity on the level and volatility of power prices. We find that as the price sensitivity increases at the demand side, power price as well as its volatility decrease significantly. We also argue that the celebrated Herfindahl-Hirschman Index to measure market concentration is not a suitable metric for power markets.

Die vorliegende Arbeit beschaeftigt sich mit Gleichgewichtsproblemen unter Gleichgewichtsrestriktionen, sogenannten EPECs (Englisch: Equilibrium Problems with Equilibrium Constraints). Konkret handelt es sich um gekoppelte Zwei-Ebenen-Optimierungsprobleme, bei denen Nash- Gleichgewichte fuer die Entscheidungen der oberen Ebene gesucht sind. Ein Ziel der Arbeit besteht in der Formulierung dualer Stationaritaetsbedingungen zu solchen Problemen. Als Anwendung wird ein oligopolistisches Wettbewerbsmodell fuer Strommaerkte betrachtet. Zur Gewinnung qualitativer Hypothesen ueber die Struktur der betrachteten Modelle (z.B. Inaktivitaet bestimmter Marktteilnehmer) aber auch fuer moegliche numerische Zugaenge ist es wesentlich, EPEC-Loesungen explizit bezueglich der Eingangsdaten des Problems zu formulieren. Der Weg dorthin erfordert eine Strukturanalyse der involvierten Optimierungsprobleme (constraint qualifications, Regularitaet), die Herleitung von Stabilitaetsresultaten bestimmter mengenwertiger Abbildungen und die Nutzung von Transformationsformeln fuer die sogenannte Ko-Ableitung. Weitere Schwerpunkte befassen sich mit der Beziehung zwischen verschiedenen dualen Stationaritaetstypen (S- und M-Stationaritaet) sowie mit stochastischen Erweiterungen der betrachteten Problemklasse, sogenannten SEPECs. / This thesis is concerned with equilibrium problems with equilibrium constraints or EPECs. Concretely, we consider models composed by coupling together two-level optimization problems, the upper-level solutions to which are non-cooperative (Nash-Cournot) equilibria. One of the main goals of the thesis involves the formulation of dual stationarity conditions to EPECs. A model of oligopolistic competition for electricity markets is considered as an application. In order to profit from qualitative hypotheses concerning the structure of the considered models, e.g., inactivity of certain market participants at equilibrium, as well as to provide conditions useful for numerical procedures, the ablilty to formulate EPEC solutions in relation to the input data of the problem is of considerable importance. The way to do this requires a structural analysis of the involved optimization problems, e.g., constraints qualifications, regularity; the derivation of stability results for certain multivalued mappings, and the usage of transformation formulae for so-called coderivatives. Further important topics address the relationship between various dual stationarity types, e.g., S- and M-stationarity, as well as the extension of the considered problem classes to a stochastic setting, i.e., stochastic EPECs or SEPECs.

This dissertation assesses the evolving structure and performance of the electricity supply industry (ESI) in Queensland following the restructuring and deregulation process undertaken in 1997 and 1998 respectively. This microeconomic reform process essentially replaced a vertically integrated electricity monopoly with an oligopolistic electricity market. In theory at least, restructuring a monopoly generator, and deregulating the product and capacity markets, should lead to lower electricity production costs, more cost-reflective wholesale electricity prices, and a generation plant expansion path that reflects the least-cost, optimal mix of baseload, intermediate and peaking technologies. In economic terms, the deregulated electricity market should deliver improvements in productive, allocative and dynamic efficiency. However, a likely side effect is a deterioration of ESI environmental performance, since the minimization of production costs are of paramount importance in a competitive market. This research has utilized historic data, direct comparisons to southern market outcomes, economic theory and the development and adaptation of a suite of economic cost and generation system simulation models to test the stated hypotheses of expected improvements in productive, allocative and dynamic efficiency, and a deterioration in environmental performance. This research has not had the availability of extensive historical market data upon which to draw. When research first commenced, less than six months of historical market data were available. At the time of completion of this dissertation, only three full financial years of data existed. Consequently, this research necessarily relied upon complex simulation models of economic cost and electricity generation systems, coupled with economic theory, to forecast market outcomes. The short history of market data is examined and tentative conclusions are drawn from this, which are integrated with the outputs of the simulation models. Simulation experiments have been conducted to identify the theoretically optimal market outcome, that is, the least-cost generation plant mix that would best meet the Queensland load curve, subject to a reliability constraint. This forms the 'base case', and represents that which would reasonably be expected to emerge under a centrally planned monopoly regime with a welfare maximization objective, characterised by perfect information and zero political intervention. Such a scenario establishes efficient generation system costs, prices and plant capacity mix. The 'base case' or centrally planned scenario is contrasted with forecast 'market scenarios'. Performance of the generation system is explored under specified scenarios using the economic cost and generation system simulation models, publicly available information about committed and expected future investment in plant capacity, incumbent generator trends and behavioural assumptions consistent with oligopolistic market theories. The analysis indicates that productive efficiency, or cost efficiency, is enhanced as a result of restructuring the monopoly generator into competing entities since competitive pressures force the generators to reduce costs in order to survive. Allocative efficiency, or price efficiency, declined during the first three years of the market, with all generators earning positive economic rents. The presence of these economic rents, coupled with conventional oligopolistic strategies associated with the theory of barriers to entry, resulted in a rush to commission new baseload capacity. Not surprisingly, dynamic efficiency appears to be deteriorating, with the market-induced capacity augmentation proving to be far greater than that considered optimal. Modelling results indicate that the oversupply of baseload capacity is expected to place considerable downward pressure on electricity prices, and thus allocative efficiency is forecast to improve in the intermediate run, much to the benefit of electricity consumers. In the long run, the oversupply of baseload capacity and subsequent low market price can be expected to frustrate the timely entry of new peaking or intermediate plant capacity, which will ultimately be required by the Queensland ESI given the strong electricity demand growth. What does appear to be emerging is a five or seven year electricity generation business cycle. Modelling results from this research also point to alarming environmental implications, with the general levels of greenhouse gas emissions of the electricity system increasing. While system thermal efficiency is declining, the rush of new, low-cost coal-fired capacity represents an inferior outcome to the alternative (i.e. efficient combined cycle gas plant) because the volume of greenhouse emissions is markedly higher. The outlook for Queensland's greenhouse gas emissions from electricity generation, in the absence of coincident environmental policies, is that they will more than double between the 1990 emission baseline, and the commencement of the Kyoto commitment period in 2008. Some clear warnings emerge from this research. The structure and performance of an ESI prior to deregulation is important if microeconomic reforms are to be successful. Too little generation capacity or transmission capacity is unlikely to provide a robust foundation for wholesale market implementation. To ensure that adequate competition will prevail, it will be necessary to restructure monopoly generators. The existing ESI needs to be characterised by ‘inefficiency’ if gains from trade are to be capitalized. An efficient centrally planned ESI is unlikely to benefit greatly from deregulation, particularly given that implementing a product market is likely to be a costly process. And finally, competitive markets deliver lowest cost, which is usually inconsistent with the most environmentally responsible outcome. As a result, if the environment is considered a policy imperative, it will be critical that ESI deregulation be complemented by coincident environmental regulations.