Just one bad cyclone, with a north to south track could take out most of Queensland wind power, or the transmission lines to get it somewhere useful. It could easily take a third of the solar with it.

Bazz,
If you've never seen 20% then you can't've been looking much; wind and solar supplied 20% of the NEM's demand on Monday this week... or 25% if you include all the rooftop solar.

Nuclear power is too expensive, and coal is too polluting. And far from seeing "why we can't afford renewables" I see yet another whinger prejudiced against renewables. They seem to be a dime a dozen on this board!

Of course replacing fossil fuels with renewables is an enormous task, but it is doable and will be done despite this government's attempts to hinder it.

You (and Graham and Shadow) seem to have failed to notice that THERE IS ALREADY A LARGE AMOUNT OF GAS GENERATION CAPACITY. Nobody disputes firming is needed, but batteries have been shown to be far more effective for that than adding yet more gas capacity. And you still seem to fail to comprehend that the objective is to meet actual demand, not replicate baseload supply!

Thanks Aidan, that's the whole story in a nutshell.

You never know Hassy, that dirty big cyclone could blow you away as well, We can only live in hope. Hassy of course you would be a nuclear man, you love them nuclear bombs.

Who said all the hard right rednecks on the Forum were racists? Look they're supporting the black fella... black Mr Coal.

Pauliar,

I have seen some willful stupidity in my time but you take the cake.

Large amounts of solar and wind make it difficult and expensive to run large low-cost baseload generation and get it to swing wildly to make up the difference between the variable demand and variable supply. However, shortfall, when solar and wind produces nothing, has to be made up or get another cock-up in South Australia.

Aidan,

Batteries are not more effective than gas as they are very expensive and can only give support to the network for a few hours before their charge runs out.

Secondly, the gas-fired peak load generators are not nearly sufficient to meet the demand in the times when the wind doesn't blow at night.

Aiden, yes I just had a look and it is 8% wind and it is 11% solar, wow !
I look at the site everyday but not always adding them together.
As it stands now, this time of year it will start dying around 4PM at
least in Sydney our time. My cells face slightly west of north and
they are down to 40% by 4PM.
I agree batteries are the ideal backup, up and running in milliseconds.
If they are big enough and you can afford them, then they are the solution.
However, no one including yourself, answers the question;
"When do you recharge them and where do you get the power to do so ?"

Another problem that I had not considered and only heard of recently
is the energy cost of building solar and wind.
We have all heard of the co2 cost of their building no one seems to
have made a study of the energy input and the energy return.
The speaker I heard seemed to be claiming that the W&S are
a next to an impossible energy proposition.
There was no indication if it included maintenance & /or replacement
energy inputs.
If the energy balance is impossible, then the whole project is impossible.
Just had a look, wind still 8%, solar now 10% = that 20%.

Bazz,
"When do you recharge them and where do you get the power to do so ?"
Whenever it is available at an acceptable price. Of course what constitutes a reasonable price is contextual and depends on demand, both real and forecast.

Wind and solar are pretty well anticorellated, and we do also have hydro power. Worst case scenario: if the prolonged dark still event occurs in the medium term, they'd keep the gas fired power stations going at night to charge up the batteries.

In the longer term, when we move to 100% renewables, there would be a large overbuild of renewables, with the excess power being used to produce hydrogen (for industry and export). If, after hydrogen production is turned off (since that would only be economic when electricity is cheap) there's still too little power to charge the batteries, the obvious solution would be to consume some of the hydrogen to make more

"Another problem that I had not considered and only heard of recently
is the energy cost of building solar and wind."

Come off it - you've been droning on about EROEI for years! Have you already forgotten that report a few years back that fudged the figures by "converting" non energy inputs into energy inputs in order to get the figure for renewables down below seven (a totally arbitrary limit which people illogically claimed was the minimum needed for an advanced society)?

Anyway, technology's moved on from them, and the figures for both soar and wind have improved so much that the energy cost is generally not regarded as a concern any more.