Three Gorges dam wall completed (BBC)

[eppur_se_muova]

China has completed construction of the main wall of the Three Gorges Dam - the world's largest hydro-electric project.
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When its 26 turbines become operational in 2009, the dam will have a capacity of more than 18,000 megawatts.
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Over a million people have been moved from their homes to make way for the project and more than 1,200 towns and villages will disappear under its rising waters.

Environmentalists say the water behind the dam is already heavily polluted.

China says the whole project will cost about $25bn (£13bn), but environmentalists estimate it to be several times higher.
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more: http://news.bbc.co.uk/2/hi/asia-pacific/5000092.stm

The Three Gorges Dam, the largest dam ever built and a project decades in the making, has been highly controversial almost since its inception. Proponents say the dam is needed for flood control -- flooding on the lower Yangtze has caused disastrous loss of life many times throughout China's history. Opponents have criticized the project for the ecological consequences of blocking the river channel to migrating fish and other species, and for the ecological and social effects of submerging a huge land area, including the sites of hundreds of villages, as well as archaeological sites (some of great antiquity), not to mention the splendid scenery of the Three Gorges themselves. Few enterprises present such a stark dilemma for national leaders--the safety of human lives and the growing demand for power in an oil-importing country vs the longer-term, often less tangible, sacrifices of environment and landscape. It is easy to see what is wrong with the TGD project, but hard to imagine what other course China's leaders might have chosen to follow, given the constraints they face, most especially the sheer scale of any energy solution in the world's most populous country. It seems certain that environmentalists will be watching the growing reservoir very closely, to the extent that China's gov't permits. If China is open in its dealings with enviromentalists and the press regarding the effects of the project, it may well be doing the rest of the world a valuable service, whatever the outcome. There will probably never be a larger dam built on Earth, and whatever the mistakes or successes of TGD, at least it can serve as a unique "learning laboratory" which will shape--or perhaps rule out--subsequent water projects.

To view China's official take on TGD, go to http://news.xinhuanet.com/english/2006-05/13/content_4540727.htm

[rurallib]

1. More Chinese factories to take more US jobs!

And we probably financed most of the cost with our trade imbalance.

[NNadir]

2. This thing is so weird.

On one hand, one has to feel that anything that retards the use of coal is a good thing.

On the other hand, one is deeply pained by the enormous environmental destruction wrought by this thing.

There is no such thing as environmentally free energy, and the Chinese have as much right to a decent standard of living as anyone in the West. The Chinese are doing something to control their population, and they are very agressively persuing better energy options - many of the trend setting work in Energy and Fuels comes out of Chinese laboratories.

Still, this is such a loss. I really don't know how to feel about it.

[Dead_Parrot]

3. I have to support it...

18+Gw is a lot of coal power that won't be built - and they use a bit of sanity, they could add a lot of wind using TGD as a backup. It is a disaster for the flooded area, but it's also about 7½ billion tons of carbon that won't be added to the atmosphere: A tiny step on the road to sanity.

[rfkrfk]

4. math check

one kilowatt-hour, about one pound of coal

assuming 24 . 365 operation, which is dooubtful.

18,000,000 kilowatts . 365 . 24 . 1 . multiplies to -->

1.576 ^ 11 , divide by 2000 --->

79 milion tons per year, not all that much

[Dead_Parrot]

5. Reality check...

Life cycle emissions for coal are ~1.3 Kg/KWh. And unless the Chinese are really crap builders, it's going to last longer than a year: I plumped for 50 before it silts up.

[rfkrfk]

6. where do you get 1.3 kg?

the numbers I use are,

coal. 10,000 BTU, or so
kilowatt-hour is 3214 BTU
typical themo-cycle efficincy of one-third,
chosen for easy math, it is probably better than that

[Dead_Parrot]

7. here...

http://www.uic.com.au/nip100.htm

I didn't see any point in guesstimating efficiency when I've got google. :)

[rfkrfk]

8. the reason to guesstimate...

is to avoid reading totaly bogus reports.

I direct your attention to these webpages
from the US Dept of Energy, use year 2004, total, all sectors

http://www.eia.doe.gov/cneaf/electricity/epa/epat1p1.html
http://www.eia.doe.gov/cneaf/electricity/epa/epat4p1.html

1,026,011 thousand tons of coal for electricity
1,978,620 thousand megawatt hours fron coal
...............

2,052,022,000,000 ,,,,,pounds coal

divide by

1,978,620,000,000 ,,,,,kilowatt-hours

result

1.037 pounds of coal per kilowatt hour

[Dead_Parrot]

12. What the...

And the impact of shifting a billion tons of coal - usually by diesel train - is where?

You can weigh lumps of coal to your hearts content, if it keeps you happy. That's not the same a life-cycle analysis.

[NNadir]

11. In the assumption of 50 years of operations, you have assumed the

river will flow that long.

Its sources are glaciers in the Himilayas. These, as we often note here, are rapidly disappearing.

For the short term, it may have increased flows. For the long term, it may stop flowing or its flows may be greatly reduced.

[Dead_Parrot]

13. True...

The loss of icefields would not (in itself) affect precipitation, just the pattern of flow over the year: How much that would affect flow levels down at TGD isn't something I'm qualified to vaguely guess about. It's also worth noting that most predictions for climate change include decreased precipitation for the interior of Eurasia, which could really bugger things up...

Ho hum.

[NNadir]

14. I'm guessing that the precipitation patterns will be greatly changed

by the absence of glaciers.

One of the big players in climate making as I understand it, is mountains. I would guess that the timing of flows is a huge player in the sustainability of ecosystems, including ecosystems on which agriculture depends.

What will happen to these big Asian rivers, including the Ganges and the Mekong as well as the Yangtze with the disappearance of the glaciers is, I think, unknown. My suspicion is that it is not going to be pretty. There are billions of human beings who depend on these already sick rivers. The fact that so much has been risked on unknowns is a frightening thought in itself.

If global climate change were clearly predictable, we would know what action to take. The big problem is that it seems less and less predictable. We do not know where there will be cooling, where there will be heating, where there will be drying and where there will be wetting.

[Massacure]

9. That river was so polluted before the dam, I wonder

Does the damn really cause ecological destruction, or was the river already ecologically dead?

[NNadir]

10. From what I know of it - not much - some species have been eliminated

by the dam.

A river with that much population and that much industry in a developing country is not a healthy river to be sure.

The dam will however slow the rate at which pollutants are washed out. I have already heard the reservoir described as a vast toilet.

[blindpig]

15. Well, their fresh water dolphin is toast.

It might be possible to save the Chinese Alligator through captive breeding, the choice of last resort. No doubt a number, perhaps dozens of endemics less known will never become better known.