Serbestleşme sürecindeki bir elektrik piyasasında faaliyet gösteren piyasa gücü bulunan bir firmanın piyasa takas fiyatları üzerindeki etkilerinin araştırılması

For many years, electricity power industry has been controlled and managed by public utilities in many countries. Generation, transmission, distribution and retail of electricity were under the responsibility of government-owned companies. Over the last few decades, electricity industry are being liberalized and deregulated and has experienced significant changes. Although countries have preferred different strategies and approaches in privatization program and deregulation of electricity markets, common goal of them is to have a sustainable, effective and well-functioning electricity market. Few large firms are dominant in oligopoly market and these large firms may have tendency to use their market power typically by changing their offer quantities or prices. Interaction among such producers in the market also necessitates considering each effect of participants' offer strategies on market-clearing prices. In the thesis, the impacts of dominant firm's bidding strategies on market-clearing prices is investigated. Day-ahead market is modeled under some assumptions. Supply and demand are taken from various sources to be able to run the simulation. Hypothetical power producers are set up to be able to show how the model works. The model consists of two main parts, which are obtaining of reduced demand curve and formation of aggregated supply curve. Three different cases are analyzed, which are uncoordinated simulation without manipulation, coordinated simulation with capacity withdrawal and coordinated simulation with intervention. In first case, uncoordinated simulation is carried out. In this simulation, each power plant submits its offer individually based on its own marginal production cost. The results of first simulation give reference market-clearing prices, which are going to use by evaluating the effects of bidding strategies of dominant firm. Second case is a coordinated simulation and power producers submit their offers by considering all their power plants, which they have. In this simulation active player's bidding strategies are taken into account by using game theory. It is aimed to investigate the impact of capacity withdrawal on market-clearing prices. In this circumstance, dominant firm tries to find out its optimum offer strategy by considering all their power plants and the strategies of other power producers. In the third case, dominant firm is modeled as a firm trying to reduce market-clearing prices as low as possible by running all their power plants. Some power plants of the dominant firm run below their marginal costs. In this case, dominant firm submits its offers without considering its losses. To have a well-designed market, privatization program should be carefully carried out to protect price increase/decrease or volatility arisen from market power. Privatization program should not serve to generate new dominant firm or contribute dominant firm's market power. In conclusion, electricity prices should be determined in competitive market conditions without manipulation. Abuse of market power should be monitored and prevented.