Modeling maximum day-ahead market price using circular statistical methods

Electricity day-ahead market price and traded quantity present a distinct pattern between peak and off-peak hours, following a pattern that tends to repeat over a 24-hour time cycle. The cyclic nature of these variables enables the use of circular statistics. Circular statistics is a set of techniques for modelling the random nature of directional data, which are typically expressed as angular measurements, which can be used to analyze any kind of data that are cyclic in nature, such as time-of-day data measured on a 24h clock. In this study, the circular statistical methods are used for analyzing the maximum values of day-ahead market price in the Iberian Electricity Market (MIBEL). The data considered in this study refer to the hourly price of electricity observed in the MIBEL, for Portugal and Spain. Also, variables that have influence on the electricity market prices such as demand, production by technology, namely hydro, coal, CCGT and Special Regime Production (production from CHP, wind, photovoltaic, small hydro, etc.) and the strategic behavior of market participants are also analyzed using circular statistics methods. The analysis performed allowed to conclude that circular statistical methods are a powerful tool to understand market price behavior.