Transpower issues grid emergency as solar storm hits South Island

Transpower has issued a grid emergency and taken some South Island electricity transmission lines out of service because of a severe geomagnetic storm. Photo / Michael Craig

Transpower has issued a grid emergency because of a severe geomagnetic storm affecting South Island transmission lines.

Transpower said it issued the emergency notice this afternoon after taking some South Island electricity transmission lines out of service.

The decision was made because of the onset of a “severe (G4) geomagnetic storm”.

The move is set to prevent damage to critical equipment should the solar storm become more severe.

“Removing the circuits from service does not have any impact on consumers’ electricity supply,” Transpower said.

Transpower said it will issue further operational notices when the storm passes and either remove the grid emergency or provide additional information if the severity of the situation worsens.

What is space weather?

Transpower said it monitors weather in New Zealand and weather in space that can affect our power system.

“Space weather is when the sun ejects plasma and other matter in Earth’s direction. These coronal mass ejections [CME] are rare, and most people won’t notice because our planet’s magnetic field shields us from the particles.

“However, these CMEs can cause geomagnetic storms on Earth and these storms can send unwanted currents through the long electricity circuits that we manage,” Transpower said.

When the currents reach transformers in the Transpower substations or the large hydroelectric dams, they have the potential to cause significant damage.

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