  We propose a hybrid approach for the modelling and the short-term forecasting
of electricity loads. Two building blocks of our approach are (i) modelling the
overall trend and seasonality by fitting a generalised additive model to the
weekly averages of the load, and (ii) modelling the dependence structure across
consecutive daily loads via curve linear regression. For the latter, a new
methodology is proposed for linear regression with both curve response and
curve regressors. The key idea behind the proposed methodology is the dimension
reduction based on a singular value decomposition in a Hilbert space, which
reduces the curve regression problem to several ordinary (i.e. scalar) linear
regression problems. We illustrate the hybrid method using the French
electricity loads between 1996 and 2009, on which we also compare our method
with other available models including the EDF operational model.

Methodology