Abstract
In consultation with the Samoa Electric Power Corporation (EPC) and the
Samoa Meteorology Division (SMD), the Afulilo Water Storage Outlook
Module (AWSOM) that was developed as a manually operated spreadsheet
application during COSPPac-1, has now been redeveloped as an automated
web application (AWSOM-2). The Afulilo Hydropower Scheme is the largest
renewable power scheme in Samoa and is central to Samoa’s goal of
becoming 100% renewable in the energy sector by 2025. AWSOM-2 draws on
weekly, monthly, and seasonal rainfall forecast products from the
ACCESS-S forecasting system, as well as weather and climate forecasts
from global models. Additionally, AWSOM-2 draws on rainfall observations
from the dam, dam level measurements conducted by EPC and the Samoa
Water Resource Division, and power generation rates being operated by
EPC. The model incorporates physical relationships derived from studies
of how the reservoir responds to rainfall, water runoff from the upper
catchment, and losses from evapotranspiration and seepage. Samoan Met
staff operationally review model outputs, add interpretive commentary
from local knowledge and perspectives, and then forward the reservoir
storage outlook report to EPC. This enables EPC to consider options for
water use for power generation and optimise water use while maintaining
a guaranteed electricity supply. AWSOM-2 has been coded in python by
NIWA, through funding from the NZ Ministry of Foreign Affairs and Trade.
The application is run on the CliDEsc server at SMD.