Chile's spectacular Patagonian rivers threatened with dams.

http://news.yahoo.com/s/nm/20060616/lf_nm/environment_chile_dc

Chile provides most of it's electricity (53%) from hydroelectric plants. Fourty-six percent of their power comes from conventional thermal electricity, mostly from Argentine natural gas imports. The remainder is "other renewables." The country is being surveyed for geothermal capacity and a 300MWe geothermal plant is planned.

http://www.eia.doe.gov/emeu/cabs/Chile/Electricity.html

Chile has no nuclear plants. The new dams would provide slightly less power than two modern ABWR. Chile is expected to have a 4000 MWe shortfall by 2015 and reportedly has been looking into nuclear power.

...but probably necessary. Dams are horrible things, but at least they don't release CO₂, and given that Chile will be years away from getting a reactor online (maybe decades) this will get them off some that Argentine gas in the mean time...

...lowest external cost.

We have to respect these calculations in view of the seriousness of current crisis of global climate change and fossil fuel depletion.

But I'm not sure if we really know what the consequences of eliminating every free flowing river on the planet will be either.

Hydroelectric dams are not CO₂, or more generally greenhouse gas, neutral. They inundate forests and it is known that the reservoirs represent a source of methane and carbon dioxide. A reservoir can cover tens of thousands of hectares of land.

The low external cost of hydroelectric power is nearly matched by nuclear energy by all calculations. Nuclear is somewhat worse, but most of the external cost is related to the long term release of radon from tailings and spent fuel. This problem can be addressed, and in any case, the difference in external cost is trivial when one starts with fossil fuels.

Further we know that there are fewer limits on the ultimate resource with respect to nuclear power: Hydroelectric capacity is mostly exploited already and it's not like new rivers and gorges are about to appear from nowhere. Further this is some suspicion that the cost of global climate change will include the elimination of glaciers on which many hydroelectric projects, including the much discussed Three Gorges Project depend. In contrast we know many ways to extend uranium and thorium resources for millenia, if not indefinitely.

When we look at the history of nuclear power, we see that the industry scaled to a gigawatt capacity within one or two decades. Somehow I doubt that these proposed Chilean dams can be built any faster than that.

I'm not happy about these dams. I'd rather they not be built. Somewhere on this planet, in at least one place, there is a river too beautiful to destroy.

I know. I think dams (in general) actually release more GHG from the processing of the cement than they do from drowned vegetation, but that's a moot point - give a dam 70 years with a decent turbine and it'll piss all over the fossil equivalents in terms of CO₂.

I should mention that my surname is Lewthwaite: Translated from the old Norse, it means "On a small hill in a forest clearing". We have have living on hills, overlooking valleys, for over a thousand years, and the prospect of deliberately flooding a valley is something I'm actually genetically opposed to.

But we live in interesting times.

Chile is going to take a long time to start a nuclear industry from scratch - even you must admit that - while this is a quick fix.

Imagine a guy with gangrene in his foot: You, as the surgeon, have the choice of sitting back and watching him die, or sawing off his foot.

I'm afraid I support hydroelectric the way you support nuclear power. If a "quick" fix does the job, it'll do. To be honest, I'd flood every fucking valley on Earth if it would eliminate fossil fuel.

industry there has to start from scratch.

There are lots of nuclear vendors and all of them would like business.

AEC, the builder of the CANDU, has experience building reactors in Argentina. The experience was not necessarily a happy one - Argentina went bankrupt during the building of the last plant - but I'm quite sure that AEC would be quite ready to transfer its Argentine learning to Chile. Two reactors operate in Argentina. Brazil also operates two reactors and has a third well under construction but currently stalled.

At the end of the day, I am not convinced that the dams can be built faster than nuclear plants. We know we can build nuclear plants in under three years. We built more than 100 plants in this country in, effectively, less than two decades. Chile, its tragic history notwithstanding, is not a third world country. I suspect too that the short term greenhouse gas pulse associated with the dam building may end up being bigger than the corresponding pulse from building the nuclear plant.

On some level, I understand very well your gangrene argument, and you know on some level I make the very same argument. In these times we must give up something, I know, but I really struggle with my decidedly middle class "free river" ideology. I hate the Glen Canyon dam here in the US, and the Hetch Hetchy as well. They hurt my heart. I think as sources of power these dams are easily replaced with non-greenhouse gas energy. At some point, before they silt over or run out of water, they should be blown up.

I am trying my damnedest to be at least ambivalent about Three Gorges though. Everybody knows China is burning a shit load of coal and anything that produces greenhouse gas free energy in China must be supported. (The same is true of the US, I'll only support blowing up Hetch Hetchy after there is no natural gas burned in California or coal in Nevada.) I do note that the most expensive energy disaster in history in terms of loss of human life was the failed Banqiao dam in China in 1975. (It was actually a serial dam failure.) That under noted energy disaster killed hundreds of thousands of people in a single night. I have no right to think like an energy paranoid given my history here, but Three Gorges makes me feel at least uneasy.

These Chilean dams, though, are going to produce about 3500 megawatts. That's peanuts. We could produce that much power on 100 hectares easily with nuclear power with a plant the size of Palo Verde. Chile could produce all of its electricity by nuclear means very easily, less than 10 reactors. I am convinced they could build all of them in ten years.

However, on your side is the valid argument that nuclear plants are continuous load and hydroelectric can operate either continuously or as peak load capacity. This argument probably doesn't make much sense in Chile though, since they already have considerable quantities of hydroelectric capacity. They probably could leave their existing capacity to cover this need, and substitute nuclear for their baseload now generated through hydroelectic means.