This paper introduces the electric Modular Fleet Size and Mix Vehicle Routing Problem with Time Windows (eM-FSMVRPTW), which deals with introducing new types of electric vehicles for urban freight delivery taking into account the possibility of recharging at a customer location. These electric vehicles differ from battery electric vehicles because their modules are autonomous in terms of consumption and electric charging. Therefore, the eM-FSMVRPTW is a completely new problem. Its objective is to minimize the acquisition cost, the total distance travelled and the recharging costs taking into consideration several constraints such as modularity, electric charging, time windows, capacity limit and others. As a solution method, we propose an approach based on a genetic algorithm. The experimental results demonstrate that with the modularity feature, using electric vehicles for freight delivery in urban environment is interesting economically.