One of the most important resources in wireless sensor networks is energy, since, in general, batteries cannot be recharged. The information about the amount of energy available at each part of the network is called the energy map and can be explored by routing algorithms. In this work, a new routing algorithm for wireless sensor networks is proposed. The key idea is to combine concepts presented in trajectory-based forwarding with the information provided by the energy map to determine routes in a dynamic fashion. Simulation results revealed that the energy spent with routing activity can be concentrated on nodes with high energy reserves, whereas low-energy nodes can use their energy only to perform sensing activity. In this manner, partitions of the network due to nodes that ran out of energy can be significantly delayed and the network lifetime extended.