Severe Geomagnetic Storm Triggers Grid Emergency in New Zealand

Transpower, New Zealand's national electricity grid operator, declared a grid emergency on November 12, 2025, due to a severe geomagnetic storm classified as G4 on the NOAA scale. This storm prompted the temporary removal of several South Island electricity transmission lines from service to protect critical infrastructure from potential damage caused by geomagnetically induced currents.

South Island power lines taken offline as severe solar storm hitsThe New Zealand HeraldGeomagnetic space storm lights southern skies — and shakes up satellites, comms, and the power gridPBS News HourABC News AustraliaThe Guardian

Geomagnetic storms occur when coronal mass ejections (CMEs) from the Sun release charged plasma that interacts with Earth's magnetic field. The current storm is part of the Sun's 11-year activity cycle, which is nearing its peak. This cycle has been marked by increased solar activity, leading to more frequent and intense auroras, particularly in southern regions.

The GuardianPBS News HourABC News AustraliaGeomagnetic space storm lights southern skies — and shakes up satellites, comms, and the power gridSouth Island power lines taken offline as severe solar storm hits

Transpower emphasized that the precautionary measures taken would not affect electricity supply to consumers. However, the decision to take transmission lines offline was crucial to safeguard transformers and other vital equipment from surges that could lead to costly repairs or replacements. A spokesperson noted, “Removing the circuits from service does not affect electricity supply, but it helps protect vital equipment should the solar storm intensify.”

South Island power lines taken offline as severe solar storm hits

The geomagnetic storm has also created opportunities for skywatchers to view the aurora australis across large parts of Australia and New Zealand. Astronomers have indicated that the southern lights could be visible as far north as Sydney and Perth, with Tasmania and New Zealand positioned for optimal viewing. Dr. Sara Webb from Swinburne University described the night as “the best chance for people to catch a glimpse of the aurora,” advising observers to find dark locations away from city lights.

The GuardianABC News AustraliaGeomagnetic space storm lights southern skies — and shakes up satellites, comms, and the power gridPBS News Hour

While the measures taken by Transpower were deemed necessary for infrastructure protection, some critics argue that the public should be better informed about the potential impacts of such solar events on technology and daily life. The lack of widespread awareness regarding geomagnetic storms and their effects on power grids and communication systems remains a concern.

South Island power lines taken offline as severe solar storm hits

Transpower stated, “This is an important step to prevent damage to critical equipment should the storm get worse.” The Bureau of Meteorology in Australia also issued an “aurora alert,” highlighting the potential for significant auroral displays due to the ongoing storm conditions.

ABC News Australia

There are varying reports regarding the extent of the storm's impact on technology and communications. While some sources indicate that widespread outages are not expected, others caution that users of satellite services like Starlink may experience temporary slowdowns or signal dropouts due to increased atmospheric drag.

Geomagnetic space storm lights southern skies — and shakes up satellites, comms, and the power grid

As the geomagnetic storm continues, Transpower will monitor conditions and provide updates on the status of the electricity grid. Observers are encouraged to check local forecasts for aurora visibility and to stay informed about potential impacts on technology and communications systems.

South Island power lines taken offline as severe solar storm hits

• “Removing the circuits from service does not affect electricity supply, but it helps protect vital equipment should the solar storm intensify,” — Transpower Spokesperson

South Island power lines taken offline as severe solar storm hits

• “It is quite an intense geomagnetic storm, one of the largest that we’ve seen in recent years,” — Dr. Sara Webb, Swinburne University

The Guardian