Analysis of the Nonlinear Response of Electricity Prices to Fundamental and Strategic Factors

This paper seeks to characterize the nonlinear effects of exogenous factors on wholesale electricity price formation. Using a special type of regime-switching, the logistic smooth transition regression model, we capture the mean-reverting and spiky characteristics of spot prices, and at the same time, estimate their rather complex relationships to fundamentals. We show that for different trading periods within the day, prices can be a function of fundamentally different drivers. In addition to including the usual fuel price, demand and reserve margin drivers, this analysis tests whether a market concentration variable is as significant in the high-frequency context as it is known to be over the longer term. The analysis is also innovative in testing the nonlinear influence of carbon emission trading.