Aitutaki is the next in line as the Cook Islands seeks to be 100 percent reliant on renewable power sources by 2020.
The northern islands already have solar arrays providing their energy, and the Cook Islands Investment Corporation says work is also underway on the southern islands of Atiu, Mauke and Mitiaro.
Its chief executive, Mike Henry, said Aitutaki's development was to receive a major financial boost in the Budget in June.
He says $US2.71 million was to be allocated and would be used for a range of purposes.
"In the form of one megawatt of solar, battery storage - which is very important in keeping the whole grid stable, and then an additional 240 kilowatt diesel generator. Those things combined will reduce the consumption of diesel fuel on Aitutaki by $NZ250 thousand dollars [$US174 thousand dollars] per year. This will allow the power station on Aitutaki to reduce the tariffs."