Making electric power grids smart is invariably linked to the implementation of an advanced communication infrastructure that is able to transport sensing, control and automation information timely, reliably and efficiently. Reusing the power line themselves to realize (part of) this infrastructure is an obvious choice that has a long and successful track record with power utilities. In this paper, we propose to make use of the fact that the nodes of a power line communications (PLCs) network are stationary to deliver messages fast and energy efficiently through routes consisting of a series of communication links. In particular, we exploit location information of PLC nodes to route a message along a favorable path. Such geographic or geo-routing is particularly apt for PLC networks with time-varying link qualities, where optimal routes will change with time. We present routing algorithms and protocols for unicast, broadcast, and multicast transmission that use network topology knowledge to determine the message path taking energy and delay constraints into account. We focus on the distribution domain of the power grid and propose decentralized solutions that use of information about the communication neighborhood of a node, which is acquired through proper signaling in the grid.