People accept instinctively statements like 'it's not economic to grow bananas in the Simpson Desert'. However if you point out the shortcomings of wind and solar it is regarded as blasphemy. Intermittent sources of energy are held out as a saviour that will cleanse all our sins. The fact is compared to producing their rated capacity on a 24/7/365 basis wind and solar aren't there 60-90% of the time. Coal, gas and nuclear are there 90% of the time.

The supposed fixes for this intermittency including over building, connecting distant sites and energy storage. All of this costs money and may still fall short. Neither large scale (photovoltaics + batteries) or (solar thermal + molten salt storage) will cover overcast conditions more than a day or two in duration. Yet realtime wind and solar are paid a premium in the form of subsidy but they don't provide a premium service. That means the despised fossil fuel backup generators (probably gas fired) have to save the day.

Just how much wind and solar should go in the generation mix is an unresolved question. If batteries come down in price 75% like solar panels their role could increase. Therefore subsidies must be temporary with CO2 restrictions as the key incentive. Let the market figure out the least cost combination for a given CO2 rate.

Wow! An academic who can actually think, see through the bull dust & get to the facts.

Thanks Don, for an interesting article. But tell me, do any of your old friends & associates still talk to you?

Every dollar spent on renewables other than hydro is money given to a spiv or ideological nutter.

The penny has finally dropped that wind and solar do not work. The reason why they do not work is simple; they are intermittant.

Tom Quirk has an interesting article on this intermittancy:

http://aefweb.info/data/Wind%20farming%20in%20SE%20Australia.pdf

The important distinction is between installed capacity [ic], capacity factor[cf[ and the new boy, what Tom Quirk calls, reliability point [rp].

Looking at Table 1 from Tom's paper we can see the usual suspects; if we use Cullerin range we can see that the ic is 30MW and their cf is 34% or 10.2 MW.

That 10MW is the actual power produced as an average over a period, usally at least a 1/4.

What the rp shows is the probability at any one moment of that cf occuring; for Cullerin it is 3%; so what I take from that is that at any moment the odds of the Cullerin installation producing usable electricity is 34/100 X 3/100 = 0.0102 or negligible.

The only way around this is to store the power from the wind or solar farm and release it as usable electricity in a steady flow; but that has 2 insurmountable problems; the first is storage and the 2nd is the simple fact that if you are storing the power produced by wind and solar you can't be using it at the same time.

People who have promoted wind and solar and who are still making money through subsidies should be held to account.

Solar and wind power sounded like a good idea to anyone outside the electricity business, but the difficulties if using them on 24/7 grids that have to be constantly balanced for frequency and power with teh load on teh grid always changing are vast. In small quantities they might actually save some carbon, but in large chunks they can destablise the grid and require too much spinning reserve back-up (meaning they don't save much carbon).

The SA grid, which has lots of wind power, can be balanced by importing power from the other states, so spinning reserves aren't required. But wheat happens when all of Easter grid has lots of wind??

As I've pointed out before there are, in any case, real problems with expanding the renewables base. http://www.onlineopinion.com.au/view.asp?article=14297 .. and they are adding to power prices just at a time when network investment is pushing prices through the roof. Time to scale back our commitment to green power.

Solar and wind generated electricity can and do contribute to reducing use of fossil fuels but not to replacing them – at least not until ability to store large quantities of energy have been developed.

However, there is one source of energy, already in use overseas, which does produce electricity 24/7/365 and can replace fossil fuels: geothermal heat. Hot granite located 4,000 – 5,000 metres beneath the surface, mostly in South Australia, Queensland and the Northern Territory can be and is being accessed by drilling.

Water injected down one hole is superheated by underground hot rock and forced up a second hole as steam which is used to drive a turbine and generate electricity before being re-injected down to the hot rock. This closed loop system is free of emissions and enables uninterrupted electricity generation which can be fed into the National Grid.

Heat mining is now being widely undertaken in Australia with a view to producing reliable, clean, continuous electricity generation. Geothermal energy is already used to generate electricity in Australia and many other countries.

Wet geothermal works because as in Iceland and New Zealand you are basically sitting on a volcano.

Dry geothermal does not work; the rock is too far down and the steam recondenses on the way up, assuming you can drill through the rock in the first place, and if you do you don't cause a land slippage which is far more common than with fracking.

No viable dry geothermal exists anywhere and as Flannery's Geodynamics shows at the cost of $100 million of taxpayers' dollars the technology just isn't viable in Australia; it's as hopeless as wave or tidal power.

Another interesting thing about geothermal is that as the superheated steam comes up it releases millions of tonnes of sequestered CO2 from the surrounding bedrock.

The fact is the alternative to coal already exists, nuclear with Thorium waiting in the wings.

Without the lie and scam of AGW renewables would remain in the fringe where they belong.