There are a few factors which determine how much power your portable solar panels gather such as size, the amount they're used and number of sunlight hours they are exposed to. One of the biggest misconceptions of solar power is that all sunlight created is equal. There are also a number of factors which affect the output of your portable solar panel including geographical location, time of the year, temperature and cloud cover.
With these factors combined it makes it difficult to give a definitive answer on how much power your portable solar panels will gather. The map below highlights the amount of sunlight the various regions in Australia receive on average per day. Useable sun hours can vary from over 11 hours in Karratha to just 5 hours in Hobart, significantly varying the amount of charge generated by a portable solar panel.
The Image below shows the amount of sunlight the various regions of Australia receive on average per day.