Hunga Tonga-Hunga Ha’apai volcano ash causing power outages in Tonga – utility provider

By RNZ

Tonga’s main island of Tongatapu has been experiencing power outages caused by corrosive ash created by last year’s Hunga Tonga-Hunga Ha’apai volcanic eruption.

Electricity provider Tonga Power said there had been four outages as a result of corrosion caused by the ash which had solidified on electrical cables.

According to Tonga Power, the ash had corroded the “High Voltage Aerial Bundled Cabling” installed before the Hunga Tonga-Hunga Ha’apai volcanic eruption.

The cables were meant to be more durable and capable of withstanding strong cyclone winds but despite these upgrades, the ash had eaten away at the powerlines, damaging the cables inside.

Tonga Power business manager Andrew Kautoke has called it a “crisis”.

“The reason we call this a crisis is because this is one of the first times this has ever happened in the network, especially seeing that it is an impact from the volcanic ash,” Kautoke said.

A cable damaged by corrosive volcanic ash. Photo / Tonga Power

“The amount of times these power outages have occurred is four times, which started on September 2022 ... that’s the scale of the power outages.

“Most of our power outage has occurred in the Nuku’alofa district ... the faults that have happened, have happened in the Nuku’alofa district.

“There’s are also homes that are connected to the feeder, so other villages that are part of that feeder will also have the power outages.”

According to Tonga Power officials, residue had increased friction in the wires.

Heat from sunlight and the cable itself exacerbated the corrosion caused by abrasive ash, resulting in short circuits across Tongatapu’s network.

A damaged wire was displayed by Tonga Power officials at a press conference held in Nuku’alofa.

Chief executive Finau Moa said the damage occurred over a period of time.

“The ash sticks to the wire and grazes it … and it becomes a problem,” Moa said.

“After it finishes eating away at the skin, it damages the wire inside causing a short circuit.”

The Hunga Tonga-Hunga Ha'apai eruption on January 15, 2022.

Meanwhile, Kautoke said the Tonga Power team were currently surveying the damage and more outages were anticipated.

He said all damaged wires would have to be replaced, and all power line cables would need to be meticulously cleaned to prevent erosion.