Simulation and optimisation of renewable energy systems

This paper discusses the experience obtained through the use of a simulator of a renewable energy system, in both grid-connect and stand-alone modes. A system containing wind, solar, energy storage and stand-by plant is modelled. The simulator calculates energy flows on an hourly basis, using actual typical daily loading, wind and solar distributions in the western Sydney area. In stand-alone mode, the model shows the relationship between improving system availability and component rating and system storage. It also shows a rapid 'law of diminishing returns' effect, whereby the objective of complete energy independence would, although theoretically attainable, be prohibitively expensive in practice without some sort of stand-by plant. The model was also used to demonstrate the potential gains of using predictive procedures, based on seasonal averages of wind, solar and load, to optimise the scheduling of stand-by plant or in the case of grid connection, grid interaction.