The increased environmental awareness of these days urge companies towards energy efficient production. This work focuses on the consideration of power consumption since the design stage of a production system. A new Assembly Line Balancing Problem is introduced in which each task is associated with a power consumption. The aim is to find an assignment of tasks to workstations that minimizes the overall power peak while complying with given maximum cycle time and number of workstations. An Integer Linear Programming formulation is proposed and tested on benchmark instances enhanced with power features. Numerical results are discussed.