As part of the Cook Islands' renewable energy goals and TAU's ongoing transition to a cleaner energy future, TAU is introducing an advanced automated control system to support the reliable integration of renewable energy into Rarotonga's electricity network. 

The purpose of this new system is to continuously manage the hybrid power network, coordinating solar generation, battery storage and diesel generation to ensure electricity supply remains stable, secure and reliable. Maintaining the right balance between electricity supply and customer demand is critical to preventing power disruptions and ensuring the network operates safely at all times. 

Currently, increases in solar generation are managed by reducing output from diesel generators. While this is effective, this can require diesel generators to operate at very low levels, reducing efficiency and potentially affecting their long-term performance. The new controller is designed to enable renewable energy sources and battery storage to be managed more effectively, reducing reliance on diesel generation while maintaining system stability. 

This project builds on several recent network upgrades that have strengthened Rarotonga's electricity infrastructure and prepared it for greater renewable energy integration. One of these improvements was the successful implementation of TAU's upgraded Supervisory Control and Data Acquisition (SCADA) system, which provides visibility to key generating sites on the TAU power grid. 

As the project enters critical stages, thorough testing will be undertaken to ensure the controller performs as intended. Over the coming weeks, TAU will be supported by specialist engineers and project partners to carry out a series of tests as part of fine-tuning the controller to meet the specific requirements of TAU's power system. 

While widespread customer impacts are not anticipated, testing will require three planned electricity outages affecting a small number of customers in Rangiura Back Road (Nikao) and parts of Avatiu Valley beyond the Power Station. 

Testing is scheduled for Friday 28, Saturday 29 and Sunday 30 August 2026, from 1am to 5am each day. 

As a precaution, if you have concerns about your appliances, we recommend unplugging them from the power point until power is fully restored. 

View a map highlighting the affected areas [here]. 

TAU will communicate directly with affected customers wherever possible and provide any further updates should the testing schedule change. 

These works represent another important milestone in TAU's investment in a stronger, smarter and more resilient electricity network. By enabling higher levels of renewable energy while maintaining a secure and dependable power supply, the project will also help position Rarotonga for a more sustainable energy future. 

TAU thanks the community for its continued support and understanding as these necessary improvements are delivered for the benefit of all electricity consumers. 

Our teams are on call 24/7 to respond to faults. We encourage customers to be familiar with their connection number and to save our fault line: 25257. 

Please reach out to our friendly Customer Services Team on phone 20054 for any questions or concerns. 

Meitaki Maata.
TAU Management

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Published date: 21 August 2026