In "Adapt solar panels for off grid power in Queensland floods" I asked if it would be possible to adapt the solar panels typically placed on homes for use when the mains power fails. These systems are normally designed to synchronise with the mains power and have no battery backup, so when the grid power fails, the solar array switches off. It should be feasible to use one panel in the array with a battery to supply a small amount of emergency power. Retailers such as Jaycar Electronics (and Altronics) sell Solar Charging Controllers starting from $50, plus batteries and inverters.
A simpler solution would be Jaycar Electronics Self Contained Solar Lighting System for $179. This has a 10W solar panel (with built in battery regulator), a 12V 8Ah sealed lead acid battery, a 12 volt 5W compact fluorescent lamp and two1W LED lamps. To that might be added a 12V car cigarette lighter socket so that 12 volt devices could be powered, such as a USB power adaptor for charging phones. A small 230VAC Inverter could be plugged in, but would not run for long from the battery. Also by limiting the system to low voltage, the safety is enhanced.