Cook Islands hybrid renewables power system

Client: Ministry of Finance and Economic Development (Cook Islands Government) (funded by Asian Development Bank, Global Environment Fund, European Union and Japanese PEC grants)
Location: Cook Islands
Date: 2015–2017

Developing and integrating renewable power systems to provide secure and sustainable electricity in remote areas.


The Cook Islands is a group of 15 small islands in the South Pacific. Entura is helping the Cook Islands reduce reliance on diesel fuel and achieve greater energy security, self-sufficiency and sustainability through designing and implementing hybrid isolated power systems on six islands of the Cook Islands Southern Group. The country’s goal is to produce electric energy from 100% renewable energy resources on all islands by 2020.


Entura has been engaged as the owner’s engineer for the implementation of renewable energy power systems for the islands of Rarotonga, Aitutaki, Atiu, Mitiaro, Mangaia, Mauke. In Phase 1, Atiu, Mitiaro, Mangaia and Mauke will move from a diesel power supply to a solar–battery hybrid system, operating at 95% renewable energy with diesel backup. In Phase 2, the islands of Aitutaki and Rarotonga, which have higher power demands, will increase their use of renewable energy to near 25% by using fully integrated solar–battery–diesel hybrid systems. The total solar PV to be installed is 3.6 MW, with 12.4 MWh of energy storage, across all six islands.

As owner’s engineer, Entura assessed the technical, environmental, social and economic viability of these projects and recommended optimum solutions. The assessments included solar energy yield for proposed sites, upgrades to electrical distribution systems, preparation of technical specifications and tender documentation (including solar and electrical concepts designs, and evaluations of tenders), and management of procurement of the turnkey solar installations.

Entura’s team includes local specialists to help manage and monitor the projects. During implementation, Entura will help to ensure that technical standards and specifications are delivered, and evaluate the outcomes of the project.

Entura will also deliver strategic advice to assist with energy policy development for the Cook Islands, evaluate the impacts on electricity tariffs and subsidies and develop practical training for local operations and maintenance workers, including in demand-side management and energy efficiency.


Once completed, these projects will reduce the Cook Islands’ reliance on diesel power generation, which will reduce diesel costs as well as lower emissions and help the Cook Islands reach its environmental targets. Four smaller islands will achieve their goals of approaching 100% renewable energy, and two larger islands will be on their renewable journey, which will easily allow additional renewables in the near future.

Finally, Entura’s capacity-building activities aim to ensure that the client and the community will be able to operate, maintain, optimise and further develop the power systems successfully for the longer term.