Adding up the value of wind farms
by
Geraldine Hinter
A model developed by UniSA researchers to calculate variability in
the electricity generated from wind farms could be a key tool for future
planning of the state's renewable energy sources.
What is important in electricity generating systems is not just how much power can be generated but how variable or reliable that supply might be, according to Dr John Boland from UniSA’s Centre for Industrial and Applicable Mathematics and Environmental Modelling Research Group.
“Electricity generating systems that rely on natural forces, like wind or solar energy, experience variability. If energy suppliers can predict drops in voltage or expected power shortages at peak times, the stability of the supply can be maintained using backup measures,” he said.
The mathematical model was developed for the Electricity Supply Industry Planning Council. It includes data on output variability at different time scales based on the statistical characteristics of Starfish Hill Wind Farm and wind measurements from the Bureau of Meteorology.
The model will be used as an important tool to calculate what the output variability might be for a diversified system of wind farms, including wind farms under construction or planned for the future, based on wind characteristics in different parts of the state.
Run by Tarong Energy, Starfish Hill (pictured above) was selected for its consistently strong winds and is considered to be one of the best locations in Australia for wind-generated power. The wind farm generates enough power to meet the annual energy needs of Kangaroo Island and the local Fleurieu Peninsula (18,000 households).
“Being able to predict the output variability at different time scales is very important. Electricity is dispatched in five minute intervals so it is important to know the level of variability in the generating system over that time frame,” Dr Boland said.
“Knowing the output variability in half hour time frames and longer is particularly important to meet peak demands because power suppliers need sufficient forewarning to start and reach the operating level necessary to meet demand.
“But the most important reason for moving to renewable energy is to cut greenhouse gas emissions and reduce our ecological footprint.”
It is estimated that Starfish Hill will reduce Australia’s greenhouse gas emissions by the equivalent of up to 2.1 million tonnes of carbon dioxide during its forecast 25 year operating life. Other wind farms now in service or under construction in South Australia will multiply those savings ten times.