Analysis and long term forecasting of electricity demand trough a decomposition model: A case study for Spain

Proper planning for the dimensions of an electricity production and transmission system requires the availability of medium- and long-term electricity demand projections that are sufficiently reliable. Generally, these projections are directly linked to the estimated growth for the whole real GDP (gross domestic product), although an in-depth historical evolution of this demand, as that given in this article, advises the explicit consideration of several determinants. The aim of this paper is to present an alternative analysis of the demand for electricity based on a simple growth rate decomposition scheme that allows the key factors behind this evolution to be identified. It is possible, taking this scheme as a starting point, to develop a long-term forecasting model to obtain projections of electricity demand given the expected evolution of the key factors. The proposed methodology is illustrated using Spain as a case study to obtain demand projections till 2030.