#3 penultimately, there are Pebble reactors. These also can be mass produced/factory built and then trucked onsite as bolt on modules, ready to provide power in just weeks!
The coolant is helium; meaning, they can be located virtually anywhere, given there's no reliance on water.
The marbles, (pebbles) of enriched uranium are coated in a grape fruit sized ball of toughened (virtually bullet proof) graphite!
The same sort of material/ceramics, that we use as molten metal vessels!
This design concept ensures if for any reason the coolant supply is shut down or lost, no melt down or collecting of fissile material is possible; nor the resultant critical mass.
And given they can be mass produced in factories, and then trucked on site; means they are also very suitable replacement for the larger diesel engines in many shipping vessels; certainly, almost entire navies; (export and fit) but only if we're actually lead by pragmatists, actually able to put aside personal considerations; and or, after politics careers/consultancies, in favor of the national interest!?
And a mass production and power within days once delivered and bolted on, means nuclear power, as shown, is now also vastly cheaper than coal! But then and only then, where vastly less problematic thorium is not practical!
T.B.C. Rhrosty.

#4. Finally there is solar thermal. And no we aren't currently building any, but we could. Scales of economy, and fluoride/thorium salts (24/7 power) have brought these babies down to the cost of coal, whether measured against roll out times or costs, or the availability or 24/7 power.
And they only need be sited in arid desert land not suitable for any other purpose.
So it could be a thousand or more hectares?
What other viable purpose would or could you use such land for!?
And they would, I'd imagine, what one might consider, if also considering the roll out of very rapid rail and or, nationwide electric vehicle recharge stations. [And we are able to look at working examples in both Arizona and California?]
And something that would require the sort of finance only Bill Gates or a sovereign economy could muster.
I'd favor a sovereign economy, on the grounds, their borrowing costs are usually half that of the private sphere!
And their subsequent costs structures are not also necessarily burdened by tax imposts, nor shareholder ever rising expectations!
So now, with all the necessary R+D done and dusted, what other possible reasons can we search around for, to enable the inevitable delays, or obfuscation, the four trillion plus a year fossil fuel industry are rolling out, along with their endless survival methodology/mechanization equivocation!?
Rhrosty.

The solutions actually look a lot closer than they did even a few months ago.

http://aviationweek.com/technology/skunk-works-reveals-compact-fusion-reactor-details

or for those who prefer moving pictures

http://www.youtube.com/watch?v=UlYClniDFkM

More R&D is certainly needed, but the cost of finance is arguably a bigger barrier. Renewable power has a much greater infrastructure requirement than fossil fuel power, but a lower running cost. If the required return on investment wasn't so high, we'd have far more power at cheaper rates than fossil fuels could provide.

The same conditions favour nuclear, though not to the same extent.

________________________________________________________________________________________

Rhosty, methane is the main component of natural gas. Wouldn't it make more sense to integrate the two than keeping them separate?

And where did you get the crazy idea that thorium reactors don't suit national grids?

I agree with the general sentiment that R and D for energy needs to be increased and the cost of alternative energies needs to be kept as low as possible.

However, how will the increased R & D be funded?

We had a carbon price of up to $25 for 2 years. It has minimal (about 8%) impact on electricity prices and there's no way it was 'crippling the economy'. It was funding R and D through ARENA and addressing the finance problem through the CEFC. These have been dismantled / de-funded by the current government.

They have replaced successful climate action with a taxpayer funded scheme to subsidize industries that may decide to undertake energy efficiencies or other emissions reductions. Most experts believe IT will struggle to achieve even 5% emission reductions

Re solar thermal electricity: Yes it only works in direct sunlight so needs sunny, climates with very little cloud. But it does NOT require the sun to be 'virtually overhead'. I recently toured the Solar Reserve CST plant in Nevada (Lat. 38 deg.N). It has tracking mirrors and molten salt storage and is designed to operate for 20 hours a day at full power in summer.

An excellent article with reasonable, balanced comments.

One technology not mentioned is predictable regular TIDAL power. Tidal can be seen as more frequently available hydro-electricity without the need for particular river-dam combinations. The prdictable nature of tidal puts it ahead of solar and wind power.

Tidal power from the worlds oceans (near Sydney, Newcastle, etc) is a technology which demands much more research and practical testing.

Pete