The use of Wireless Sensor Networks (WSNs) are a promising technology that can enhance various aspects of today’s electric power systems, including generation, delivery, and utilization, making them a vital component of the next-generation electric power system, the smart grid. However, harsh and complex electric-power-system environments pose great challenges in the reliability of WSN communications in smartgrid applications. This paper presents wireless sensors with magnetic harvesting capabilities deployed along Underground High Voltage Power Lines (UHVPL) to allow long-lasting operation. The paper includes an overview of the communication protocol that optimizes sensor node coordination in linear array arrangements. Based on an optimal time synchronization method, the wireless sensors can self-adjust the communication timing in order to minimize the total power consumption. In addition, the paper provides a description of a linear sensor network under test, the results and discussions concerning network reliability and power efficiency. ; Peer Reviewed ; Postprint (published version)