This report presents the findings of a feasibility study of an Energy Storage for Rarotonga. The report was developed by DNV KEMA for Te Aponga Uira (TAU) to assess the need and feasibility for storage for the Island of Rarotonga under selected future generation scenarios. The Cook Islands enjoyed a high level of electrification. However, the energy supply has been heavily dependent on imported fossil fuels, exposing the Cook Islands to the risks of energy security and international oil price volatility. The project phase's main objective is to gain experience with wind power on Bonaire and reduce short-term electricity generation costs.