Structural Health Monitoring System for Micro-hydraulic Power Stations Through Water Level Monitoring with a Wireless Network of Optical Sensors

The current context in the energy market with a growing energy demand requires the employment of efficient renewable sources. This is the case of micro-hydraulic power stations, which provide reliable and decentralized energy since early 20th century. However, many of these infrastructures, built decades ago, are obsolete and need important updates to gain efficiency and ensure structural integrity. Furthermore, these power stations are usually placed in remote areas and subject to flooding, landslides or vegetation in different parts of the infrastructure such as the canals, penstock and forebay that endanger the integrity of the infrastructure and are only detectable by human inspection. Water level monitoring in different parts of the infrastructure plays a critical role, since allows detecting and localizing these issues by differences in water level between separate localizations on the power station. In this paper, we present a water level monitoring system based on optical time of flight sensors with 10 mm resolution. Each sensor has a 3.7-year autonomy connected to a wireless network through LoRaWAN protocol, to monitor the integrity of the micro-hydroelectric power station. Furthermore, the monitoring system is low cost, based on Arduino technology and 3D printing parts.