As a rough rule of thumb, based on analysis  in Australia, to achieve a one hundred percent   00:08:21 renewable electricity grid, you need about one  gigawatt of power for every one million people,   plus probably twenty hours of energy storage  to give yourself plenty of leeway from the five   hours minimum number in the recent studies I  mentioned earlier. So that’s twenty gigawatt   hours of energy storage per million people in a  well-connected high-energy-use country like Aus,   with good wind and solar resources. That equates  to a total Australian requirement of about   00:08:46 five hundred gigawatt hours in a country that  has storage potential about three hundred times