Geomagnetically induced current (GIC) has been a significant concern for the electrical power grid in high latitudes for decades. Its origin starts in the Sun; during extreme space weather, the magnetic field of the Earth varies rapidly. This variation induces electric fields at the Earth's surface and leads to GICs in manmade technologies. Power systems are the most affected by this induced current, which causes halfcycle saturation of power transformers and other issues. Understanding the behaviours and chain effects of this phenomenon is the key consideration in modelling the hazards to technological systems from space weather. In this paper, a comprehensive review of space weather, geomagnetic disturbances (GMDs) and GICs and their impacts on the power systems in both high and mid-low latitude regions is presented. Additionally, we highlight the most commonly used methods to model and calculate geoelectric fields at the Earth's surface and GIC in the power systems with respect to DC and AC analysis. In addition, we have classified the GIC effects on the different power system components. Moreover, the possible solutions and mitigation techniques to eliminate or reduce these effects based on different GIC blocking devices are reviewed in this work. This work provides researchers and power system operators a shortcut road path to understanding GIC phenomena, modelling and calculations, effects, and mitigation of these effects.

Installing surge protection devices in a hybrid photovoltaic (PV)–wind system is essential to guarantee the survival of the system’s components. If the surge arresters are connected without taking into account the recommendations given by standards, the equipment to be protected might be damaged despite the energy coordination of the arresters. In this study, nonlinear surge protective devices (SPDs) are designed for a multi-MW hybrid system based on lightning protection standards with optimised threat level ratings to investigate the mitigation of lightning transients to an acceptable level. The system is implemented using Power System Computer-Aided Design for Electromagnetic Transients including Direct Current (PSCAD/EMTDC) software. It comprises a 2 MW PV farm, a 2 MW wind farm, and a backup energy storage system (ESS), which are all connected to a 132 kV grid via a step-up transformer and a transmission line. The results were obtained at critical system nodes for two standard lightning current surges, i.e., 1/10 µs and 10/350 µs, considering two lightning strike point scenarios with and without a lightning protection system (LPS). The simulation results showed that the connected SPDs could successfully limit the transient overvoltage in the system to an acceptable level. The analysis in this work is crucial for designing, operating, and maintaining a hybrid PV–wind system. It can help to find the potential vulnerability areas within such a system and implement appropriate protection measures since there is no available lightning standard for such systems. Additionally, it assists the system operators in increasing the uptime and dependability of their RE systems, limiting expensive downtime and environmental effects while optimising energy output. Based on the results obtained, recommendations were made for lightning protection developers.