The majority of electricity demanded is curbed through the electricity generated through coal-fired power stations. Renewable energy in Australia is still generated at maximum levels in remote areas which at distant places from the major cities of Australia therefore its role in the generation of energy for present and future is seen as marginal. As renewable energy sources are intermittent in nature thus are not the reliable sources for matching the demand for continuous levels of power or ‘base-load’ (Shafiullah, 2012). ‘Base-load’ is a term used for defining the amount of electricity needed for meeting the continuous demand for electricity for 24 hours a day for whole year. It is used essentially for industrial processes used for continuous periods and even for services of traffic lights and hospitals etc.
There are nominally just two coal-fired power stations in South Australia and it even has minimum fifteen wind farms in operating conditions. The electricity generation in Australia through wind energy is approximately 27% on an average annually (Evans, 2012). One among the two coal stations is shut down for the whole year and the other one is shut down for half year. The system of supply of electricity in the state is operating at reliable levels and there exists no need for the supply of electricity through non-renewable energy sources. According to the projections made by the federal government’s Bureau Resources and Energy Economics (BREE) about the costs of renewable energy an optimal mix of various renewable sources is found. This optimal mix includes wind energy about 46%, electricity generated through heat of sun i.e. concentrated solar thermal and the thermal storage energy of about 22%, 20% photovoltaic solar i.e. generated through direct sunlight, gas turbines which are bio-fuelled is approximately 6% and hydroelectricity is about 6% (Johnstone, 2010).
Thus it is estimated that two third of the energies for annual consumption are derived through wind and solar photovoltaic sources and they even vary on the weather conditions but the reliability of the energy generating systems is maintained at a certain level (Panwar, 2011). The two sources i.e. wind and solar photovoltaic are unable to meet the demands of electricity for just few times in a year. These peak periods are of winter seasons and overcast days during which the flow of winds is low with slow speeds in the whole region.