The effect of geomagnetic storms on the Spanish power grid could be similar to other countries of similar latitudes, as in the case of South Africa, and for that reason, the Ebro Observatory has investigated the effects of GICs in the Catalan electricity transmission network. This proposal aims to extend this study to the whole of the Spanish network. Its target is analogous to the E-CEPR-10010-GIC project aims: Prediction and monitoring of geomagnetically induced currents in the electrical system of Endesa and risk assessment, roughly: modeling and analysis of the network vulnerability, this time of the REE transmission grid and validation of this model from measurements.