What a fascinating thread this is. Knowledgeable people, cranks, ideologists - all contribute. And I a mere layman feel naked and illiterate.
We need an environment of thought and decision that is as free from selfish interest or ideological contaminent as possible.
What are the facts that we must weigh?
I know that in wishing for a decision making process that is as free from selfish or ideological contaminants I am baying from the moon. But how can we, as simple but intelligen laymen, set up a system of governance that is most likely to produce good for our children, grandchildren and subsequent generations?
I wonder if our problems are as much psychological and social as technical?
Fencepost.

There's nothing wrong with ideology, Fencepost. Providing it's backed up with science and a thorough knowledge of how government and industry technocrats do business - mainly with each other of course!

A touching post Fencepost. Stimulating. Good.

I am becoming an old man and recognise nuclear "power" for what it is - an old man's dream. An old man's delusion.

Nuclear "power" is a better mousetrap. An absolute bonfire of irreplaceable, once-only liquid hydrocarbon fuel. It is the childish dream of one last glorious cracker-night. Let it all go up in a shower of cinders. Tomorrow is Sunday - sleep in - no worries - no school.

Never trust the judgement of old men where nuclear power is concerned, nor their younger wannabees, who want to be just like them when they grow up.

It's a loony idea.

France will shortly supply 76% of its electricity needs from nuclear. It also does this safely and comparitively cheaply.

The reason for this is "No oil, no gas, no coal, no choice."

Comments above try to imply that the only reason that renewable energy isn't as cheap os other sources is that there isn't a free market (quoting authorative sources such as rolling stone magazine). Come on! With the public sentiment against the large power corporations in the US, renewable generation has been the white knight for decades.

Wind, solar and other technologies have made great progress, but are still decades from being able to meet the base load requirements on a sustainable basis.

The reason we can keep debating this is because we have oil, gas and coal. Take this away, and to quote the French we have "no choice"

"Wind, solar and other technologies have made great progress, but are still decades from being able to meet the base load requirements on a sustainable basis."

You cannot claim that with any certainty. What is true is that 25% of domestic power is used to heat water, so solar hot water heating alone could substantially reduce this in a much shorter time frame, and much faster than nuclear power plants could. The potential of solar thermal power should be better understood within a few years.

Democritus,

"base load" power is defined in terms of generation, not demand. The base load concept dominates electric economics only because most generation comes from big furnaces, boilers and steam turbines. This is NOT a law of physics, but of legacy capital. Switching off is anathema to operators of these dinosaurs: "PLEASE dump cheap power overnight, rather than make us relight the furnace (or reactor) in the morning." Customers exist, of course, but off-peak electricity remains a recipe for fuel wastage and grand-scale greenhouse pollution.

You're quite wrong about the capital costs of peaking generators, BTW. It is idle time and premium fuel (or head of water), not capital, that makes peak generation relatively expensive.

Replace big power stations with small cogenerators (where "waste" heat is useful, not belched away in cooling towers) and switching off overnight becomes the obvious thing to do. The economics are dictated by the technology, nothing else.

The CSIRO study you cite is too pessimistic, but correct in essentials. Intermittent generators can't provide all of a network's capacity, but a sufficiently diversified supply is worth a capacity credit up to two-thirds of its average capacity factor (~20% for well-sited wind power, higher for solar thermal or wave power). After all, the wind never stops blowing everywhere at once. CSIRO don't seem to allow for the distinct possibility that all Australia's "base load" generation might eventually come from solar thermal and/or geothermal power. Fuel is only indispensable in the absence of hydroelectric peaking capacity.

The whole discussion seems to forget that we can't change everything overnight. Existing (especially shiny new) power stations are never going to be retired wholesale and immediately replaced with low-carbon technology. A migration to a low-carbon electricity supply has to start somewhere, and the greenhouse-mitigation goal is served best by starting *now*, with the small(ish) low-carbon generators that already compete with high-carbon options under consideration.

No matter how much backup capacity sits idle in case of a bad power day, *every* kilowatt hour of electricity generated from a renewable source is a kilowatt hour that wasn't generated from fossil fuels.