The Alaoa Hydro Electric Project was built and commissioned in 1952 and was the first hydro electric scheme to be installed in Samoa, the electricity generated was exported to the local grid network which provided the power to the Islands capital city Apia. Up until the late 1990’s over 85% of the nations electricity was generated from hydropower. However, growing demand due to increased provision of electricity to the wider population and uptake of improved electricity services such as refrigeration, air conditioning and televisions has reduced hydropower’s proportion of supply to 50% and below.
The Electric Power Company has recognized the importance of reliable hydropower to the island and has undertaken to invest in its existing and potential hydro infrastructure. The Alaoa turbine was the first of four turbines that Gilbert Gilkes and Gordon have supplied to Samoa. Over the last 58 years the Alaoa turbine set has operated reliably without any major modification to the mechanical or electrical equipment. The current owner and operator EPC (Electric Power Company) of Samoa issued a tender to either modernise or replace the existing turbine, generator and control switchgear. Gilkes tendered for the mechanical and electrical work in partnership with Tenix Ltd of New Zealand completing the civil elements.
Scope of supply
- Replacement turbine runner and shaft assembly
- Conversion of the turbine deflector and spear valve to hydraulic actuation
- Supply of hydraulic control module
- Supply of a Gilkes digital speed governor
- Replacement 6.6kV generator and AVR
- Generator control & protection panel
- 6.6kV/22kV Transformer
- DC Battery Backup system
The replacement components and design changes to the actuation and re-governing of the turbine was all completed from the UK without the requirement to take the turbine out of service for inspection and measurement.
This was possible due to all the original design files being available from Gilkes archives. The turbine was re-commissioned in June 2011 and is yet again proving to be reliable. As a result of the work on the Alaoa scheme Gilkes are now looking at other refurbishment opportunities in Samao on there other hydropower stations.
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