Stand-Alone Power Systems (SAPS) have been an alternative and a solution for many decades to power devices, telecommunications, buildings and communities that experience practical or financial barriers to grid electrification, be it in rural areas or in developing countries. SAPS have been used to provide small scale portable lighting, water pumping, and power for general consumption. Nowadays there is growing interest in SAPS in more urbanised areas and in developed nations. The growth of information technologies and an increase in the participation of renewable energy in electricity generation have given rise to the idea that SAPS can be implemented in these regions. Despite a current strong focus on grid-connected renewable energy systems, renewables in stand-alone power is an area of significant growth in Australia, with the amount of PV capacity installed off-grid each year steadily increasing.