Hi thirra,
You have raised several good points. I raised CCS because this appears to be central to Garnaut report and white paper thinking. No investment of $$ billions is going to occur without considering "what if" CCS does work! The point I was trying to make was that this technology has not been proven and will take until at least 2020 to know if it works at a reasonable cost, so new coal fired plants are going to be risky, hence the need for renewable energy.
The point about geothermal energy using hot rock, is that it shows great promise, but until 100MW capacity is built and running its going to be hard to know the costs and to finance 1GW let alone 10GW capacity all in 12 years.
The risk of power lines to fire is a lot less in the low rainfall regions, and even 2GW capacity is still only a small part of overall power. Note that power plants in gold fields rely on one pipeline, so a grid electricity supply is adding a second back-up.
As far as I can see the carbon trading scheme is aimed at making coal fired power much much more expensive. The most recent Garnaut report that very few seem to have read, indicates that carbon price may go to $60/tonne CO2e, costing coal fired electricity 6cents/kWh just for the pollution permits, about 300% higher than present costs, making it more expensive than wind, solar or geothermal.