Our problem is to describe what would be involved in running Australia (in particular South Australia) predominantly on renewables.
In order to focus on this problem, we exclude others from consideration. While we have various views on climate change and nuclear power (to mention the two big ones), you will not find these laboured here. . . .The big problem with renewables, particularly wind and solar, is that 'the sun don't always shine and the wind don't always blow'. That is to say, these are variable sources of power, and we want to introduce them into a system that is currently "electricity on demand".
The variability of renewable power can be managed in various ways: (i) by having different renewable technologies in different places (so that if one source isn't making much electricity, others might be), (ii) storage (such as pumped hydro, thermal storage, and chemical conversions), (iii) demand management, and (iv) backup systems (gas turbines, probably).
But wait, I hear you cry, there are renewables such as geothermal and ocean currents that -are- regular. Which is (sort of) true, but are these technologies tested and ready to roll? And how much power can they produce?The next big problem is cost. While people might be prepared to pay a bit more for electricity (and for the things that use electricity in their production - which is just about everything), massive price hikes are unlikely to be acceptable to society at large. While we do not start with a full economic analysis, in all the work we do on this site we have these economic aspects in mind. Before policy makers can make decisions, before investors put money into infrastructure, options need to be costed.