Leaders in Penrhyn and Manihiki in the north of the Cook Islands have told the New Zealand foreign minister they are concerned about depopulation.
Murray McCully visited the islands with the Cook Islands prime minister, Henry Puna, this week to open a solar project on Penrhyn, and cyclone shelters on Manihiki.
He was told the number of Penrhyn residents dropped from 351 in 2001 to 213 in 2011, and is believed to have again fallen to about 150.
Mr McCully says he wants to address the issue.
The prime minister's chief of staff, Elizabeth Koteka-Wright, says the renewable energy systems are designed to meet 95 per cent of the electricity demand, which will reduce diesel use by over 230,000 litres a year.