the challenge

Rarotonga is the largest island in the Cook Islands and the centre for international tourism. Historically, all electricity generation on the island has come from diesel generators managed by Te Aponga Uira (TAU), Rarotonga’s power company. Over the last decade, there has been a steady increase in the number of solar photovoltaic (PV) installations in Rarotonga, which has increased the island’s renewable electricity generation to about 8% of total generation.

As solar generation increased, it became harder for TAU to maintain a constant voltage on the network, because smaller diesel generator networks are particularly susceptible to fluctuations from renewable generation, causing power and voltage surges. In 2019, TAU made a decision to halt all new solar generation assets on the electricity network in Rarotonga.