The power of water French government interested in solar because it uses less water than nukes

[Javaman]

http://gristmill.grist.org/story/2009/3/26/15247/0136

A year or so ago, I spoke at a solar conference in France -- a country that produces 78 percent of its electricity with nukes. A couple of folks told me that the government's interest in solar stemmed from the fact that during the previous summer's heat wave, river levels dropped to the point that they didn't have enough water to cool the reactors. The country actually had to shut off generation exactly at peak demand. Big problem. Thus, solar photovoltaics, which not only generate most during these peak events, but also ... use no water.

A Wall Street Journal blog flags the water/power problem, but concludes, in that special WSJ way, that this is bad news for efforts to fight climate change:

"The irony is that efforts to fight climate change could make the situation even worse: The National Energy Technology Laboratory estimates that "clean coal" plants that capture and store carbon emissions would make the power sector an even bigger consumer of water if the still-to-be-developed plants are widely deployed in coming decades. That's because it takes more energy and water to capture and store the emissions than it does at a regular coal plant."

Note that PV uses no water. Concentrating solar thermal technologies do, but some have the potential for dry cooling, which adds about a penny per kWh, but greatly reduces water usage.

(that's all there is)

[Bread and Circus]

1. So, they are saying water might be the rate limiting step for nuclear?

Interesting, I never thought of that before.

[madokie]

2. A while back I asked if Nuclear power plants used more water

for cooling than a coal plant and I was told by a very respected poster here that they don't. I can't find a link at the moment but I remember reading that Nuke plants do indeed use much more cooling water. Anyways I just thought I'd throw that in there.

[Javaman]

3. interesting how the pro nuke usual suspects here on DU haven't chimed in yet.

I'm waiting. LOL :)

Cheers.

[phantom power]

4. You know...

I think people will choose the kind of environmental impacts that they want to incur for their energy.



Also, I'm meltiiiiiiiiiiiiing!

[Massacure]

6. All thermal power plants use water as a coolant.

How much water is a direct result of how much heat you have to get rid of and how much you are willing to raise the temperature of the local environment. A steam turbine might only convert a third of the heat energy of a nuclear or coal power plant into electricity. So that means a 1500 megawatt power plant is actually consuming 4500 megawatts or 15 billion BTUs worth of fuel. One BTU can raise the temperature of a pound of water by a degree. If you only want to raise the water temperature one degree, you need to use 15 billion pounds of water each hour, or roughly 1.8 billion gallons. If you are willing to raise the water temperature by five degrees, you only need to use 1/5 of that. What fuel you use to create those BTUs is irrelevant.

[madokie]

7. The difference is in the amount of heat produced

a coal plant and a nuclear plant are totally different animals in that regard. Nuclear power plants use a larger quantity of water because of the higher heat produced in the reactor. I've read a while back what the difference is but I'm not having any luck in finding it again to give you a link, I will be looking for that info though.

[nomorenomore08]

5. I don't think any one "alternative" source can entirely replace fossil-fuel power.

Rather, I think it'll have to be a combination of many different methods, from nuclear to solar to geothermal and beyond. Not to mention advancing hydrogen-based technologies in the decades to come.

[NNadir]

8. What a crock of shit. The entire ground water system under San Jose California is

contaminated forever because of the "green" semiconductor industry that operated there.

http://books.google.com/books?id=qfvlzm1A1vMC&pg=PA80&lpg=PA80&dq=groundwater+San+Jose+tanks+leaking&source=bl&ots=3h1C02OMda&sig=RluoVRzwyqgxWCxchabHpd1Hwd4&hl=en&ei=NZzNSbG9IpPUlQfUnrTxCQ&sa=X&oi=book_result&resnum=5&ct=result

The waste profile of solar energy is exactly the same as the semiconductor industry.

The reason that the toxic solar industry escapes attention for its huge external costs is that it is - and has been for the last 50 years - a trivial and meaningless form of energy, unreliable, costly, toxic and essentially useless.

If solar energy ever gets to one exajoule out of the 500 exajoules of energy now used by humanity, its toxic profile will become obvious. But it isn't there, won't be there, and probably shouldn't be there.

[kristopher]

9. Thank you for the truth in labeling

You wrote: "What a crock of shit" to introduce your post. That was the most truthful thing you've ever posted.

[jpak]

10. LOL!!!!!111

:rofl:

[hunter]

11. Nuclear plants are designed for the amount and temperature of water they've got.

When the French plants were designed there was no expectation that river flows would be so low, and that water temperatures would be so high. Thus the nuclear plants could not be run at full capacity.

It's not impossible to build an air cooled nuclear power plant -- there are a number of air cooled natural gas power plants throughout the world -- and obviously there are many thermal power plants of all sorts cooled by seawater, so there is nothing peculiar to nuclear power concerning water use. France has seafronts.

As with any thermal power plant the engineers and political process determines how much water the plant has to work with and the plants are designed for that. Power plants are less expensive to operate with greater volumes of cooler water, and fossil fuel plants can generally be run hotter and in combined cycles, unlike current nuclear power plant designs. This means fossil fuel plants can use smaller cooling systems than nuclear plant of similar capacity, but that's all it is, nuclear plants are water hogs because they are designed that way to save money.

Which all begs the question -- if France has an unusual string of cloudy hot humid days, will these solar plants be labeled a terrible failure?