This article explores the possibilities of substituting internal combustion vehicles (ICV) by fuel cell vehicles (FCV) refueled with hydrogen generated by electrolysis during the hours of low demand in the electrical grid, having been estimated that this substitution ratio would be below 25% of the total number of vehicles existing today, against the 100% in the case of using electric vehicles. Furthermore, a network of 322 hydrogen stations would be necessary for refueling the maximum number of fuel cell vehicles, given the actual limitations of the electrical grid for hydrogen generation. Thus, considering that hydrogen used for refueling would be generated by electrolysis using the electrical grid, fuel cell vehicles would only be a 4% less polluting than an internal combustion vehicle. However, if we could achieve a substitution ratio of 25% of the total (CV by FCV, the Autonomous Region of Murcia could avoid the emission of up to 24,500 metric Tons of CO2 to the atmosphere every year. This value contrasts with the 2.2 millions of metric tons of CO2 that could be avoided using electric vehicles. (C) 2014 Elsevier Ltd. All rights reserved.