I am not entirely gung-ho on wind power, nor am I even a determined anti-nuclear zealot, but I think it's worth adducing this study I found last night:

http://www.sustainability.vic.gov.au/resources/documents/Greenhouse_abatement_from_wind_report.pdf

Apparently existing wind power in the state of Victora has a truly impressive capacity factor of 37%. Of course the first wind farms occupy some of the best sites, so performance wouldn't be quite so outstanding in aggregate with greater wind penetration.

The daily profile of wind variability peaks in early evening in summertime with a strong midday and afternoon ramp-up, corresponding well to the afternoon air conditioning electric load peak (as would intermittent solar power generation). Unfortunately the useful correspondence between intermittency and peak demand means that wind power displaces relatively clean gas-fired peaking generation rather than Victoria's massive dirty brown coal furnaces, but on the bright side it means wind power is already cheaper to integrate than I would have expected given the preponderance of gigawatt-scale coal power stations.

Winter is the least windy season, and Victorian winter wind doesn't match the seasonal evening heating/cooking demand peak so well, but even then it's hardly "windless"; indeed the profile indicates that wind power in Victoria is mostly capable of supplying "base load" demand up to almost 20% of its rated capacity. Rarely, the total wind power output will fall below that level, so some backup in the form of peaking generation or severable loads (desalination plants, anyone?) would sometimes be required to compensate. Any shortfall would be predictable many hours, even days, in advance.

Anyway. Enough on that topic. Wind turbines are just cheap, not a magic bullet. Diversity is key. End-use efficiency is a cheaper investment than any form of electric generation technology. Cogeneration eliminates fuel wastage. Geosequestration and algaculture will help mitigate the greenhouse pollution of coal. Wave, tidal and solar thermal power techniques improve daily. Solar photovoltaics are dropping in price just the way flat-screen TVs did (see http://www.nanosolar.com).

If every one of those fails to live up to its promise, we might have to consider fission more closely.

Xoddam

Now there's talk of a hybrid wind/power unit to complement each other. When the wind fails the solar takes over and vice versa.

Yes there's much to be done on renewables but it continues to look very promising.

I remain convinced that coal-fired powered plants conversion to gas fired plants, for an interim period, could reduce GHG by up to 50% though I doubt the technocrats or our politicians are listening since the approval of new coal-fired power plants continues.

Tragic:Continuing:

Now bringing wastewaters close to the coast works well in winter where heat swirls around the arctic ocean and back up the East Australian coast, but in summer forget it! All the heat is coming from the dead centre and the closer they are making those wastewater plumes off Sydney the more intense the ambient heat conditions will be.

SHA map 0ct 3 2006: http://www.aoml.noaa.gov/phod/trinanes/tmp/sha1191421438.gif

If authorities want to get rid of drought and bushfires now and through summer they need to almost totally recycle wastewaters, not just shift them around. Of course reutilising the Sydney deep outfall will improve the situation and should be implemented immediately. But its not going to be a drought-buster and that's what is needed.

Another important strategy would be to stop all immigration into Sydney. That cuts the staggering GROWTH in wastewater emissions and at least gives us a baseline to work from. To not cut immigration given the paultry recycle capacity, you are looking at nothing short of Apocalypse Sydney.

Vivor,

This SHA work shows the incompetence & secretiveness of Howard government when it comes to the security-Australia over the next 2-decades. That's relevant to nuclear debate.

http://en.wikipedia.org/wiki/Pebble_bed_reactor

1. Pebble-bed reactors can theoretically power vehicles. There is no need for a heavy pressure vessel.

2. Romawa B.V., the Netherlands, promotes a design called Nereus. This is a 24 MWth reactor designed to fit in a container, and provide either a ship's power plant, isolated utilities, backup or peaking power. It is basically a replacement for large diesel generators and gas turbines, but without fuel transportation expenses or air pollution. Because it requires external air, Romawa's design limits itself only to environments in which diesel engines can already be used.

The article also refers to the Chinese HTR 10 MW reactor prototype.

That means two things:

* the Chinese are already capable of producing small systems
* Such systems are less than the size of a container and could easily be around the size of a large car.

DO NOT BIKE TOO CLOSE-hear they have large dogs.

KAEP
Thank you for the Wikipedia link. That article says:
“The AVR [German pebble bed test reactor] used helium coolant. Helium has a low neutron cross-section. Since few neutrons are absorbed, the coolant remains less radioactive. In fact, it is practical to route the primary coolant directly to power generation turbines. Even though the power generation used primary coolant, it is reported that the AVR exposed its personnel to less than 1/5 as much radiation as a typical light water reactor.”

So, we have reduced tritium production by eliminating neutron absorption by water coolant, but what else stops the neutrons?

A link provided in the Wikipedia article,
http://www.wired.com/wired/archive/12.09/china.html,
gives some idea:
“Beneath its cavernous main room are the 100 tons of steel, graphite, and hydraulic gear known as HTR-10”

100 tons (say, about 100 tonnes metric)of steel would help stop neutrons, but I cannot understand how you would fit the necessary shielding into an automobile.

I’m also intrigued by the waste containment properties of the “pebbles”, which the “wired” article describes as the size of pool balls (not your larger tennis balls, Dickie, but the numbers you mention are not to be sniffed at).

The radioactive gases xenon and krypton are inevitable fission products, and they are not going to be contained by the pebbles. A Google results from the arcana (try "pebble bed reactor" xenon krypton)suggest that they will enter the gas stream.

Containment of radioactive gases for about 30 minutes ought to allow for a lot of their radioactive decay, but the release of radioactive noble gas isotopes will lead to the increased presence of strontium, cesium and iodine isotopes in the environment. Not a pretty sort of smog. Again, nothing to be sniffed at.

Containment of these noble gases is going to further add to the puzzle of getting your PBR-powered cars on the road, I think, KAEP.

Go nuke or perish - simple as it.

Vivor,

Good points!

But my point again is that, as a nation with 40% of the world's Uranium, our future over the next 2 decades will largely depend on solving the problems you raise.

The sooner we realise the dangers of PEAKOIL, the sooner we can set about solving those problems and moving forwards with nuclear energy.

I also reiterate the point that hot rock Geothermal will ultimately replace nuclear power if we indeed survive PEAKOIL. Another advantage of selling PBR reactors and fuel to an energy hungry world is that the profits could be ploughed back into drilling for hot rocks close to all major Australian cities. That too ought to be done as a gilt edged priority in tandem with PBR research development and manufacture. We really souldn't be gambling with our near term future in the blase way that the cargo-cult, Titanic captain mentality of the Howard government reveals. Not everything good necessarily comes to us from outside this country and Howard needs to wake up to that or get out of the way.

As for PBR cars. Forget it. Its not feasible. However car-sized reactors for shiping, small towns and military vehicles certainly are.