Transpower has lifted the grid emergency issued on Wednesday, following the overnight easing of the severe solar storm, the operator confirmed.
Strong geomagnetic storms—triggered by solar flares and coronal mass ejections—can wreak havoc on power transmission networks. When charged particles from the sun interact with Earth’s magnetic field, they induce geomagnetically induced currents (GICs) in long conductors like high-voltage lines. These currents can overload transformers, destabilize voltage regulation, and trigger widespread outages. The 1989 Quebec blackout remains a stark reminder of how space weather can cripple modern infrastructure.
In New Zealand, Transpower monitors these risks closely. During severe solar activity, it may declare a grid emergency—a formal alert indicating that the national transmission system is under stress. This allows operators to take protective actions such as load shedding, voltage adjustments, or rerouting power flows to prevent cascading failures. The declaration also prompts coordination with generators and distribution companies to maintain system stability.
But the threat isn’t limited to equipment—it extends to the people who maintain it. Line mechanics working on transmission assets face heightened risks during geomagnetic storms. GICs can cause unexpected heating in conductors and transformers, increasing the chance of burns or equipment failure during fieldwork. Protective relays may misoperate, energizing circuits thought to be deactivated. Grounding systems can become unstable, exposing workers to dangerous step and touch potentials.
To safeguard crews, utilities may defer non-essential work, enhance monitoring, and issue safety advisories. Training and awareness are critical, ensuring that line mechanics understand the invisible hazards posed by space weather.
As solar activity intensifies in the current cycle, proactive measures—from infrastructure resilience to crew protection—are essential. Transpower’s grid emergency protocols and frontline safety planning are key to keeping the lights on and workers safe when the sun turns volatile.
