Te Aponga Uira (TAU) acknowledges the number of unexpected electricity outages the island has experienced in the past week, and assures customers it is working hard to deliver reliable electricity supply.

“Firstly in addressing the number of unexpected electricity outages Rarotonga has experienced recently,” says TAU Chief Executive Officer, Lesley Katoa. “TAU apologises to the community. We have not lived up to expectations and these outages have gone beyond a minor inconvenience given the timing and frequency. The outages have been caused by two unrelated issues, and my team supported by our NZ counterparts are confident they have identified what’s gone wrong and how to fix them.

Secondly, we strive, continually, to provide reliable electricity to our customers and to visitors. Unfortunately this week we have not been able to do so, for the reasons outlined below.

Thirdly, we assure our customers that we do have the ability to supply enough electricity to meet demand. Our ability to generate enough power to meet demand is not the issue.”

Details of the issues that have caused unexpected electricity outages this week

                First Issue

• On Tuesday evening, our power station noted an additional, unidentified, source of power adding significant electrical energy to the network. As our control systems are designed to do, they automatically shut down the entire network to protect the network from damage. We were able to get the system back up and running, and started investigating the cause of this issue.
• While those investigations were ongoing, there was a recurrence Wednesday evening.
• We successfully identified that issue on Thursday morning. It had been caused by one of the BESS solar energy batteries automatically discharging energy at a time and at a level outside its design parameters. We are investigating this issue with the supplier to ensure it does not happen again, and in the meantime, we have isolated all BESS solar energy batteries from the network so that this cannot recur.

Second Issue

• Last Saturday, 22 June 2024 our cross-island cable which was installed in the early 1990s and which provides electricity from the north, directly to the south of the island, experienced a fault. It is important to note that this cable is a crucial component in our load-balancing infrastructure.
• As a result, we reconfigured our network so that electricity that usually runs through this line could be delivered to customers through our cables running around the east and west coasts of the island.
• Work to identify multiple faults on the cross-island line, and to repair them, is ongoing. Given the location of this line, it does pose access challenges, and so investigations and repairs necessarily take time.
• Last night, Thursday, two power cuts occurred that were directly attributable to the load control challenges brought on by network reconfiguration necessary for power supply, as a result of the cross-island cable fault. The recent upgrades have not directly caused these issues.
• This particular outage was caused by the connection between our two Rarotonga powerhouse switch rooms, which balance demand and supply across the island. Immediately this occurred, we reached out to our specialist partners to identify the issue, perform the necessary load calculations and recalibrate the controls.
• We, and those specialists, are confident we have fixed this issue.

“These recent events, highlight the complex nature of providing reliable electricity on an island such as ours, with the mix of renewable and non-renewable generation capability and with infrastructure that operates in a challenging marine environment. This week’s occurrences demonstrate the challenges of maintaining a careful balance of how much electricity can be delivered through various networks to our people right around the island.

We are a small, capable team here in Rarotonga, supported by experts from New Zealand, Australia, and further afield who have been available, in real time, to provide prompt remedy, fault-finding and re-calibration.

I thank all those people – both with Te Aponga, and overseas support personnel, who have been working extremely hard for long hours in recent days.  And not to forget our valued customers for your patience and understanding, we will continue to work hard to deliver what you expect and deserve.”