The hydropower scheme at Afulilo dam in Samoa currently produces around 50% of the total energy needs of Upolu Island. The remaining is provided by more expensive thermal production (diesel). The current strategy to protect against long-term drought is to be conservative in the hydropower production goals. This leads to suboptimal production in most years when drought does not occur. Therefore, opportunities exist for incorporating seasonal climate forecasts for improved management of water release for hydropower generation from the Afulilo dam.

The objectives of this study are to:

• determine the utility of seasonal climate prediction in the management of hydropower generation for the Afulilo dam;
• identify management strategies to maximise the use of hydropower generation relative to thermal production; and
• build local capacity in the use of seasonal climate forecasting for improved water resource and renewable energy management.

Outcomes (proposed/achieved)

Relevant data has been obtained from the NMS and Electric Power Corporation of Samoa. A water balance model of the Alufilo dam will be developed and used to examine the impact of alternative demand (hydropower generation) on the reliability of the dam. From this analysis, strategies to maximise hydropower production in favourable climate patterns (La Niña) and the provision of early warning indicators for energy shortage during prolong droughts (El Niño) will be identified and communicated to EPC and other government agencies in Samoa.

An operational water balance model has been developed and refined. Simulated long-term storage volume records for Afulilo Dam can now be generated. Assessing the potential of using ENSO-based seasonal forecasting in dam and hydropower management is underway (Progress August 2009).