Abstract and subjects
•Operational space-based optical lightning detection provides new information useful for electrical power systems.•Flashes producing continuing currents can be identified from space-based lightning imagers.•Analyzed upward-triggering lightning flashes presents a common optical pattern.•Identification of potential upward-triggering lightning flashes is used to estimate the annual upward lightning frequency from tall towers (e.g. wind turbines).•Satellite total lightning data are used to evaluate the exposure of lightning of an overhead transmission line.
Information about lightning activity and its parameters is necessary to design and evaluate the lightning protection of an electrical power system. This information can be obtained from ground-based lightning detection networks that provide information on cloud-to-ground lightning strikes with a location accuracy of few hundred meters. Recently, the first satellite-based lightning optical detectors are operating continuously from geostationary orbits. These imagers observe the luminosity escaping from clouds to detect and locate total lightning activity with a spatial accuracy of several kilometers. This allows delineating the initiation and propagation (sometimes over tens to hundreds of kilometers before striking the ground) not observable by the ground-based networks. In this paper, we explore the use of this new technology for lightning protection in power systems. We focus on tall objects such as wind turbines and overhead transmission lines. We show how the optical detections allow identifying lightning flashes that likely produce continuing currents. This provides additional information for the identification of dangerous events and also can be used to estimate the number of upward-flashes from tall objects triggered by a nearby flash. The analysis of a transmission line shows the concentration of faults in the areas of high total lightning flash density. We found regional variations of the optical energy of the flashes along the line.