I. Introduction
IN recent years, the deregulation of power systems is widely spread in the world. The power market becomes more competitive so that the market players are interested in the maximization of profit and the minimization of risk. As a result, electricity price forecasting is one of the most important tasks under new environment of the deregulated power systems. It is related to the complicated nonlinearity due to the load demand, weather conditions such as temperature, amount of available generations, etc. The volatility of electricity price is much higher than the foreign exchange, the interest rate, the stock prices, etc. Also, it has a feature that the electricity is not stored unlike other commodities. As a result, the behavior is hard to predict. The conventional studies on electricity price forecasting may be classified into the following:
statistical model [1], [2], [6]
artificial neural networks (ANN) [3]–[8]