"So EROEI may exceed 2 already. If not, it will soon."

Whoopty doo!And what about when the energy invested has to come from solar?

Even if it did, hypothetically, tip over 2, it still means solar would require preposterously massive infrastructure including energy storage and fossil-fueled backup (to meet residual, inevitable intermittency problems) to meet current electricity and transport needs (let alone growth). That cost will obliterate the cost of the nuclear option.

How can the major parties be deflected away from fossil-fuels and/or renewables and towards the only real CO2 mitigation option we have in our locker? Australia's Chief Scientist has a big role to play here, and I await him showing his hand.

The thread author tells its own story. Bazz has a leaning toward believing alternate bloggers as fact, when the only fact is they have invested interests.

Vested interests for god's sake.

Nothing could be more vested than those who funded Obamas election, then put their hands out for their pay off with taxpayer funding of their start up alternate power companies.

Only alternate power companies have ever managed to go broke in just 3 years after receiving half a billion, yes billion, dollars from the taxpayer.

Wonder where it went? Guess!

Scratch most shonks, & you'll find green below the façade.

Luciferase,

"Whoopty doo!And what about when the energy invested has to come from solar?"
In that hypothetical situation, the manufacturing would all be done in lower latitudes where energy returned is much greater.

But as you well know, there will always be other power source options including nuclear and wind.

"Even if it did, hypothetically, tip over 2, it still means solar would require preposterously massive infrastructure including energy storage and fossil-fueled backup (to meet residual, inevitable intermittency problems) to meet current electricity and transport needs (let alone growth). That cost will obliterate the cost of the nuclear option."
You have to specify what location you're referring to, for in sunny climates like we have here, it's unlikely EROEI will fall below 3 (and the figure's still rising). Backup is of course needed, but in the long term it need not be fossil fuelled, and in the short term it's not that expensive, as a lot of existing infrastructure could be used, and solar thermal can be designed to produce power when the sun's not shining.

"How can the major parties be deflected away from fossil-fuels and/or renewables and towards the only real CO2 mitigation option we have in our locker? Australia's Chief Scientist has a big role to play here, and I await him showing his hand."
We do need to stop having to rely on fossil fuels, but there is no good reason to avoid renewables. In Australia, which is very sunny, has a low population density and does not have a history of nuclear energy experience, renewables are likely to be the cheaper option. We should not rule out nuclear, but neither should we pretend it's the only solution.

Aiden, apparently did not notice that the authors raised the same
reservation about capital input that he raised himself.
Capital input if raised by the magic click of a bank mouse I agree is
totally devoid of energy input. It is however repaid by energy output
being sold and the proceeds being paid back to the bank, so it reduces
the out put.
That I assume is the argument for including it as an input.
Anyway anything with an ERoEI as low as 2 is a lost cause and should be
abandoned.

Luciferase has touched on the real problem, the massive need for storage.
Imagine, if you are game, the massive battery or similar device, that
would be needed to store enough electricity for say NSW & Victoria
for perhaps five days plus enough left over to restart the system
after the slow moving front moved out into the Tasman.
Solar & wind are all very nice and on Lateline last night Senator
Rihannon made it obvious that she is totally unaware of these complications.

"they have invested interests." is no answer to these problems and
to keep repeating that old chestnut has worn very very thin.

Some of Aidens comments relate to the energy costs of employees of
the solar systems.
However, the maintenance staffs truck needed energy to be built and fueled.
He needs energy and energy is used to produce his food.
He is not self supporting, he needs a house and family and energy is
used to feed them. All that HAS to come from the output of the solar
system otherwise it will breakdown and stop generating.

These peripheral energy costs have been added in for coal fired
electricity and is one of the reasons for the falling ERoEI of coal.
We do have to leave coal & oil before they leave us.

Bazz,
"Aiden, apparently did not notice that the authors raised the same
reservation about capital input that he raised himself."
FALSE.

The authors of the study did not raise that reservation. Had they done so they would have drawn attention to how stupid it would be to include it. Nor did Euan Mearns (the blogger who reviewed it) though Euan did raise about capital the reservation that I raised about labour; oddly enough he failed to raise it about labour!

"Capital input if raised by the magic click of a bank mouse I agree is
totally devoid of energy input. It is however repaid by energy output
being sold and the proceeds being paid back to the bank, so it reduces
the out put.
That I assume is the argument for including it as an input."

Firstly, an input and a foregone output are different things, and the EROEI figure is different if you include one as another.

Secondly, selling the energy output doesn't reduce it.

Energy costs and financial costs are different things, and it is fraudulent to treat one as the other.

"Anyway anything with an ERoEI as low as 2 is a lost cause and should be
abandoned."
That's not for you to determine! Net energy is still positive, so from a technical POV there's no need to abandon it. From an economic POV it's unlikely to be a good investment, but that is determined by the IRR not the EROEI.

(TBC)