A simulation tool for studying the day-ahead energy market: the case of Italy

Many challenging issues arise in the newly deregulated competitive electric power markets worldwide. Instead of centralized decision-making in a monopolistic environment, as in the past, many parties with different goals are now involved and competing in the market. Key questions to address include how to predict load and market clearing price (MCP). In this paper a simulation tool for investigating the wholesale energy market in a compulsory power exchange/ISO environment is proposed. For each generator (customer) a multi-stage nondecreasing (nonincreasing) bidding curve is considered, based on an appropriate set of quantity/price pairs. The proposed approach allows the analysis of several crucial aspects which may significantly influence MCP, profits and market shares. Using published and estimated data, the simulation tool is applied to investigate the main features of the Italian wholesale energy market that involves five main companies, represented by a specific set of generation technologies.