I. Introduction
Electric load forecasting has been an important topic for electric utilities. With the growing penetration of variable power generation and demand response projects in the context of smart grids, there is a pressing need for better load forecasting. This will help system operators to better accommodate fluctuating wind and solar power generations which effectively changes the “net load” behavior. Over the years, regression-based and artificial neural network-based forecasting methods have been widely adopted in utility industry. Multiple linear regression method has been used for electric load forecasting, considering the interactions between variables that affect electric load behaviors [1]–[3]. The method is based on the general linear regression model. By introducing quantitative, qualitative, and transformed variables, complex relationship between forecast output (load) and input variables can be captured by polynomial regression model. The model has satisfactory accuracy, which is comparable to ANN based method.