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  #21  
Old Posted Apr 11, 2007, 8:55 PM
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wong21fr wong21fr is offline
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Quote:
Originally Posted by aVegetable View Post
^ This is not a question of capability, it is a question of false economy.

Following a discussion with a friend, it has been pointed out to me that the carbon footprint of a wind farm is equal to or higher than that of a nuclear power station over the course of both their lifecycles - inclusive of complete nuclear decommissioning. It begs the question: what is the point?
I find that a highly dubious assertion. How can the carbon footprint of the windfarm be so large and what are the factors for both forms of generation?
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  #22  
Old Posted Apr 11, 2007, 10:49 PM
aVegetable aVegetable is offline
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Quote:
Originally Posted by Trantor View Post
I really do not think the carbon footprint of a windfarm or nuclear power station changes much during their lifes. Their carbon footprint only happens when they are built.

And a nuclear power station can have a nuclear meltdown, which is much worse than any carbon footprint all windfarms in the world can generate.
nearly all the [wind farm] emissions occur during the manufacturing and construction phases...These account for 98% of the total life cycle CO2 emissions.
[nuclear] Decommissioning accounts for 35% of the lifetime CO2 emissions
(source follows below)

The UK has already been through this electricity generation sham at the "forefront" of "green technology". This is a topic I have found interesting.

For a windfarm to be built and then "pulled down" to be comparable with nuclear decomissioning and the massive associated carbon footprint is absurd, don't you think?

source: http://www.parliament.uk/documents/upload/postpn268.pdf

UK Government
October 2006
CARBON FOOTPRINT OF
ELECTRICITY GENERATION



Sorry to paste so much:

Wind
Electricity generated from wind energy has one of the
lowest carbon footprints. As with other low carbon
technologies, nearly all the emissions occur during the
manufacturing and construction phases, arising from the
production of steel for the tower, concrete for the
foundations and epoxy/fibreglass for the rotor blades.10
These account for 98% of the total life cycle CO2
emissions. Emissions generated during operation of wind
turbines arise from routine maintenance inspection trips.
This includes use of lubricants and transport. Onshore
wind turbines are accessed by vehicle, while offshore
turbines are maintained using boats and helicopters. The
manufacturing process for both onshore and offshore
wind plant is very similar, so life cycle assessment shows
that there is little difference between the carbon footprint
of onshore (4.64gCO2eq/kWh) versus offshore
(5.25gCO2eq/kWh) wind generation (Fig 2).11 The
footprint of an offshore turbine is marginally greater
because it requires larger foundations.
Nuclear
Nuclear power generation has a relatively small carbon
footprint (~5gCO2eq/kWh) (Fig 2). Since there is no
combustion, (heat is generated by fission of uranium or
plutonium), operational CO2 emissions account for <1%
of the total. Most emissions occur during uranium mining,
enrichment and fuel fabrication. Decommissioning
accounts for 35% of the lifetime CO2 emissions, and
includes emissions arising from dismantling the nuclear
plant and the construction and maintenance of waste
storage facilities.12 The most energy intensive phase of
the nuclear cycle is uranium extraction, which accounts
for 40% of the total CO2 emissions. Some commentators
have suggested that if global nuclear generation capacity
increases, higher grade uranium ore deposits would be
depleted, requiring use of lower grade ores. This has
raised concerns that the carbon footprint of nuclear
generation may increase in the future (see Issues)

And for those worried about nuclear meltdowns, how many times do you think these have ever occurred? How many people do you think have died? Can you compare that to the amount of people who have died working in other electricity generation methods like coal mining? There is no comparison.


source: http://www.ecolo.org/lovelock/lovelock-wind-power.html

Dr James Lovelock:

Dr Lovelock has been a lifelong environmentalist and member of the green movement. He says the more "pragmatic" nations, such as France, Finland, Sweden, Japan and China, are embracing nuclear power as they believe it is the most viable and safe source of energy for the future.

So why are we scared of it? "I think the reason is just simple politics," he declares. "Our Government is persuaded that there are so many people in Britain who are frightened off nuclear energy by fiction, mainly films. Bad fiction written by good writers. It continues to pervade and give the impression it is the most evil thing.

"I would take high-level waste if they would let me have it. I would have it just over there," he says, pointing to the hedge visible from his sitting room window.

"We could use it for home heating. They could put in a concrete pit and it would stay hot. What a waste not to use it. People have got in mind great big glowing slag heaps. It's all nonsense."

He dismisses Chernobyl as a "nasty accident that killed 45 people" saying it was not comparable to the amount of people who die in an air crash or in an industrial accident such as Bhopal in India, which killed 3,500 people and maimed countless others.

He believes that if we are concerned about health risks we should consider how many people are dying as a result of climate change. He estimates that last summer's heatwave in Europe killed upwards of 20,000 people.

"The area around Chernobyl has been invaded by wildlife and allowed to flourish as it has been left alone. It doesn't mind the radiation in the least," he says.

"We have lived under a lot of absolute nonsense for years and years about radiation. You can't live without breathing oxygen, but it's also the most ubiquitous carcinogen of the lot. Just breathing daily is equivalent to quite a hefty radiation dose."

Apologies for the length of this post, but to stay on topic future wind turbines should be used to supplement the enerygy requirements of small scale projects in suitable (windy) locations. Large wind turbines will be a legacy of a naive "green" generation.

Last edited by aVegetable; Apr 11, 2007 at 10:59 PM. Reason: answering 2 questions instead of 1
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  #23  
Old Posted Apr 12, 2007, 7:50 PM
Captain Carpetburn Captain Carpetburn is offline
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The size of wind turbines will also be limited by the size of the generators they are attached to - I think the biggest ones in use just now are 5MW.


Quote:
Originally Posted by bosmausasky View Post
I have always wondered why the wind turbines cannot be placed closer together. It seems there is alot of space in between each turbine.

Also Highways would be a great place for wind turbines, wonder why nobody puts turbines on highways. I assume the state, local, and federal governments would be able to make a couple bucks off the deal. In addition nobody would bitch about it looking bad because the highway already looks bad.
Wind turbines create turbulence so you cant have them too close thats one reason they arent usually tightly packed - I am sure there are others.

You don't tend to see wind turbines on highways as highways usually avoid going over the tops of hills - i.e they stick to low ground and turbines are usually sited on the top of hills - where its windier.

I agree though it could look quite cool - and if you look at the visions for sustainable cities in china they have windturbines on the sides of roads - and scattered everywhere really.
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  #24  
Old Posted Apr 12, 2007, 10:05 PM
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Interesting report, aVegetable, the studies I've seen have shown that nuclear energy has a higher footprint than wind, though not by that much. I'm also guessing that this report uses shaft mining for uranium extraction rather than pit mining. If so, there would be a large increase to the carbon footprint.

I still believe that both sources have their uses, wind in more decentralized locations and nuclear for urban areas.
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  #25  
Old Posted Apr 14, 2007, 12:29 PM
aVegetable aVegetable is offline
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Quote:
Originally Posted by wong21fr View Post
Interesting report, aVegetable, the studies I've seen have shown that nuclear energy has a higher footprint than wind, though not by that much. I'm also guessing that this report uses shaft mining for uranium extraction rather than pit mining. If so, there would be a large increase to the carbon footprint.

I still believe that both sources have their uses, wind in more decentralized locations and nuclear for urban areas.
This a UK government report; I believe (althought I have no proof) that in this situation a proportionately weighted average of all techniques would be used. Otherwise the report would be purposefully favouring nuclear engergy over wind by glazing over this topic. However, the report mentions it briefly:
"The most energy intensive phase of the nuclear cycle is uranium extraction, which accounts for 40% of the total CO2 emissions."

The margins are slight:
onshore wind farm (4.64gCO2eq/kWh)
offshore wind farm (5.25gCO2eq/kWh)
nuclear power station (~5gCO2eq/kWh)

The crucial factor is the spread of the data - the graph shows that the least environmentally damaging technology available is nuclear, although less effectively built stations have a similar footprint to offshore windfarms.

I agree both technologies have their uses, but as energy requirements worldwide outpace resources (in terms of fuel and space) surely only the safe application of nuclear fission (or fusion) will fill the breach.

Or possibly the moon. I wonder what this "inexhaustible, clean, pollution-free" energy source's carbon footprint is estimated at:

source: http://news.bbc.co.uk/1/hi/sci/tech/6533169.stm

Data collected from the Apollo Moon landings have indicated that large deposits of an extremely rare gas called helium 3 are trapped in the lunar soil.

Scientists believe that this helium 3 could be used to create a new source of almost inexhaustible, clean, pollution-free energy on Earth.

One of them is Dr Harrison Schmitt, a member of the 1972 Apollo 17 mission and the only trained geologist ever to walk on the Moon.

"A metric ton of helium 3 would supply about one-sixth of the energy needs today of the British Isles," he claims.

Plans are already afoot in the US and Russia to strip-mine lunar helium 3 and transport it the 240,000 miles (385,000km) back to Earth.
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  #26  
Old Posted Jun 14, 2007, 11:03 AM
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KevinFromTexas KevinFromTexas is offline
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A Lubbock billionaire is proposing building the world's largest wind farm in the Texas Panhandle.

Here's the article on it. Oddly enough, he's an oil tycoon!
http://www.statesman.com/business/co...14/14wind.html

And another sort of related article. This one is about Applied Materials, Inc., which is the world's largest chip maker. They're putting solar panels on their chip factory in Austin and it will be the largest collection of solar panels in the city.
http://www.statesman.com/business/co...14applied.html
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  #27  
Old Posted Jun 14, 2007, 1:21 PM
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DanJ DanJ is offline
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Quote:
Originally Posted by KevinFromTexas View Post
A Lubbock billionaire
That's just a really amusing statement to me.

Cool articles though, intersting to see the change from oil to wind.
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