ttbn, ERoEI = Energy Return on Energy Invested.
It is about whether you have to put in as much or more energy than you get out.
It does not matter how much coal you have, if it takes more energy to
get it than you get out of it, then there is no point.
Australia is in a lucky position, but the rest of the world is not so lucky.
China is already there, and the US is getting close.
Interestingly updated info is hard to find.
With oil the fact that tight oil has become so important shows how
close the US is to 7.

Pumped hydro does work but there is one thing to remember and the
catch is in a renewable system the reservoir has,like a battery have to be recharged.
When and where do you get the electricity to recharge it ?
The system will be already under load when you need to recharge.
Like a two armed juggler with three balls in the air.

Yes Altrav you are right to doubt the feasibility of a 100% renewable
system. No one advocating 100%, or even 50% ever discusses how many
sequential overcast still days their proposal caters for.
The cost for catering for even two days makes the system very expensive.
That question results in a solution that requires geographical
distribution to take advantage of different weather systems, but that
dramatically increases the number of wind & solar farms.
Additionally it requires a very high capacity grid over the whole country.
Much money and high electricity bills, very high bills.

Bazz,
Your obsession with EROEI is stupid. The arbitrary threshold of 7 holds no actual significance.

What really counts is net energy return on money invested.

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ttbn,
The "enough coal for a thousand years claim is based on current rates of usage. If we turned large amounts of it to oil, it wouldn't last nearly as long.

But considering how much the burning of coal affects our atmosphere, it would be far better to leave it in the ground. We should instead use electricity (from solar power) to synthesise hydrocarbons from CO2 - or perhaps use single celled plants to produce oil.

Have a dekko at this,
http://www.dailymail.co.uk/sciencetech/article-6139773/Solar-farms-wind-turbines-Sahara-desert-increase-vegetation-rain-region.html

Wind and solar can solve all problems!!

Is Mise - Problems overlooked now not much rain so few clouds rain comes from clouds solar panels don't like clouds (don't work very good)

Also assume the change from global warming now climate change gee what happens to your power if that change was LESS wind oh no wind turbines won't work now.

Hundreds of billion of $ and no power.
Is Mise on a bicycle with a generator that picture will be priceless

Issy, not ALL problems.
In fact very few.
The example you link could work.
In the Sahara!
Wind and sun are too unreliable, normally, and will badly affect their duty cycle.
We need continual, constant power generation to have any chance at a system that even comes close to the duty of care and performance expected of it!

Sorry, correction, I should have added; the current suite of renewables are not yet fit for purpose.