The integrated planning of the natural gas and electricity systems under market conditions

The international environment has changed dramatically since the beginning of the 1990s. Emphasis has been put on the necessary deregulation of the electrical system as a means to achieve greater economic efficiency than in the past centralized and often monopolistic environment. However, the need for planning does not disappear with the outcome of a liberalized market. On the contrary, the competitive operation and location of generation capacities require efficient and up-to-date planning tools for their economic appraisal. Adequate market analysis is especially required in a competitive market when decisions must be taken in an environment that goes global with companies acting on a continental scale. Locating the assets where their production will be valued best is of uttermost importance for the companies' future return on investments. Fuel sources such as natural gas as well as generation capacities have to be taken simultaneously into account. Moreover, the market involves many competitors and the investment decisions taken by other parties are susceptible to influence the future of each company's assets. Decisions must be taken in a relatively short time, based on clear-cut analyses of electricity generation and transmission systems, often mixed with constraints issued from the gas supply and transportation system. All this implies the use of a comprehensive methodology, either for investment planning or for medium term evaluation of the operation of those systems. The PRELE model, developed by Tractebel Energy Engineering, is a comprehensive tool that tackles both problems in an efficient way. This tool allows simultaneous analysis of electricity and gas markets, on a geographical basis and with an adequate time framework. It also allows defining particular operating conditions for each of the systems, to give due consideration, for instance, to seasonal peculiarities or probabilistic unavailability of key equipment.