Warmair,

I find many of your quoted figures somewhat disingenuous. For example the "higher environmental standards" to which you refer include Gillard's carbon tax. Also if you compare modern coal fired super critical plants, they generate an additional 15% power per ton of coal, and cost about 1/2 as much in capital as wind per kW of capacity. Add on top of that that coal generation lasts about 50 yrs

Also I am dubious about the 20 days p.a. for maintenance for coal generation, as my experience is typically 5 day annual shuts with 3 yearly 3 week major overhauls or 30 days in 3 years.

http://www.power-technology.com/features/featurepower-plant-om-how-does-the-industry-stack-up-on-cost-4417756/

As for general maintenance costs the cost per kW capacity is the same for wind as for coal, but with a 30-35% capacity factor for wind and a 85-92%% capacity factor for coal, the maint costs for wind per kWhr generated is nearly 3x that of coal.

Warmair, you still did not answer my question as to providing for 3
overcast still days.
It requires a cost 3 to 4 times the cost to supply one day.
All you suggested was have larger capacity in that either wind or solar
could do the job, so that is double the cost.
Have you never heard of a cold dark still night.
That is an enormous quantity of energy to store.
Forget hydro, if you let all that water run we will starve.

>Solar power based north of the divide can

I presume you mean west of the divide ?
Have you ever been in a power station ?
If not, I think you should take the opportunity if there are any tours
run near you.

I know that wind & solar can be made to do it if enough money is spent
even though it fails energy net test, but once you add storage and
the fiddling you suggested with bios etc to cope with multiple days
then it falls in a heap.

Bazz

I acknowledge the problem but it is not nearly as bad you seem to think, first our geography means that our primary wind source runs east west, now as weather patterns travel west to east it means that it is very unusual for all the wind farms in SE Australia to be offline at the same time, and for solar again I emphasize that the center of a high is typical sunny especial north or west of the great divide. I don't how many times I have driven to the coast, left in bright sunshine crossed the divide and found myself in overcast conditions.

The primary method of providing power when wind and sun is not available is in my opinion is biomass, which fall into various categories:-

Solids from the timber and forestry industry such as trimmings, thinnings, branch off cuts, bark, sawdust and scrap from timber milling, tree clearing associated with urban development, and domestic waste. It would also be possible to harvest fair amounts wood in a sustainable way. We also have a range agricultural waste, such as straw and sugar cane bagasse.

Bio Liquids fuels can be obtained from sugar cane, coconut palms and numerous other plants, further possibilities include used vegetable oils from commercial enterprises.

Gases particularly methane can be obtained from biodigesters using both human and animal wastes and municipal rubbish dumps.

The advantage of biofuels is that fossil fuel power stations can readily adapted to use them as the British plan to do with one of their large coal power stations.

In Australia we generate hardly any power from biomass compared to Europe which generates over 60% of their renewable power from biomass.

http://oilprice.com/Energy/Coal/UKs-Largest-Coal-Power-Plant-to-be-Converted-to-a-Biomass-Plant.html

Warmair,

The problem with your proposal can be seen by simply looking at the renewable generation in Germany which swings from peaks of nearly 100% some mid days to as low as 10% in the hours after sunset. The responsibility of the government is to ensure that power is available as close to 100% of the time, and biomass generation has no chance of filling the gap.

Having worked with a Biomass boiler, the biggest problem is ensuring a steady supply. The boiler's fuel is typically light, very bulky and contains about 50% moisture which means that the calorific value is low and that transport costs are very high per unit of power generated.

Biomass can provide base load power, but beyond about 10% of Australia's demand, the costs of transport escalate dramatically until nearly as much energy is consumed burning the waste as is generated.

Zero emissions is not possible without large reliable low emission base load generation, and the only thing that fits the bill so far is nuclear.

Hasbeen, wind turbine lifespan obviously depends on the turbine design and the conditions it's used in, but I'd expect most of them to last over 20 years.
See http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_20-2-2014-9-18-49

Operation and maintenance costs for three countries are shown at... http://offlinehbpl.hbpl.co.uk/NewsAttachments/OPW/data-1.gif
...though they're not insignificant, they're nowhere near the fuel costs of fossil fuel based generation.

And it's likely maintenance costs will decline as wind turbine design improves.

Does the time peakload generators spend idle add much to their maintenance costs?

As for the warming trend, at the moment there's a huge El Niño developing. Once that makes its impact felt, we could find ourselves warming much faster.

Wind power is totally uneconomic. If wind power was economic it would not need subsidies. The subsidies for wind power are about ninety times higher than for coal fired electricity generation. That says it all.

Continually making up nonsensical, irrelevant numbers and using cherry picked out of context numbers is typical of the wind ideolgues. No rational debate can be held with such people.