Electricity industry is in the midst of revolutionary transition from outdated ageing power infrastructure to an intelligent sophisticated smart grid network utilizing modern communication technologies to enhance power generation, transmission, distribution, and consumption. Smart metering infrastructure is an integral part of the smart power grid revolution. Smart meters, in addition to their primary billing functions, serve as distributed Wireless Sensor Network (WSN) nodes for enhancing grid reliability. Existing ad hoc routing protocols are based on single routing criterion such as hop count. This single routing metric approach can overload and deplete resource constrained smart meters along preferred paths. A protocol is needed which is aware of energy level and traffic congestion of smart metering nodes. In addition, protocol should select route based on link quality for optimal routing. In this paper, a novel WSN ad hoc routing protocol ETL-AODV is proposed for reliable and energy efficient communication of smart metering nodes. Three simulation based case studies are conducted to analyze the performance of the proposed protocol, and relative comparison is provided based on four metrics: (i) packet delivery ratio (PDR), (ii) normalized routing load (NRL) (iii) average energy consumption and (iv) average end-to-end delay. © 2013 Hasan Farooq and Low Tang Jung.