Water Sucking Solar Farms Breed Water Wars

Interesting point water
for Solar thermal concentrator power plants.
The mirrors need cleaning with water too

lookatmypix, now I see from your article:

http://www.ag.arizona.edu/azwater/awr/septoct08/d3aa3f8e-7f00-0101-0097-9f672482....

"CPS uses long parabolic mirrors or Fresnel lenses to concentrate the sun?s energy on black tubes carrying molten sodium or high-temperature oil. These fluids are used in turn to boil water, with the steam turning a conventional turbine to produce electricity. CPS systems require a water source and cover large areas of land, up to several square miles, to produce sufficient electricity for export or local use. "
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So the first enclosed loop is molten sodium or oil.
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"Efforts to increase water efficiency in solar energy operations involve modifying the conventional cooling tower. For example, dry desert air could be used instead of water to cool the operation. This, however, would greatly increase building costs because enormous cooling towers would need to be constructed. Also relying on air to cool would not cool the water circulating through the plant to a low enough temperature for peak performance, decreasing the efficiency of the plant.

Woodard says hybrid cooling towers have been designed and built that are both dry and wet. In winter or in the middle of the night, with temperatures in the cool range, dry cooling is effective. When temperatures rise to a certain degree, water is then used, with devices Woodard describes as "outdoor misting systems on steroids" activated in the cooling towers.

Woodard says, ?They can be operated either as dry cooling or wet cooling towers. You get a compromise. You still use some water but not nearly as much if you were always using water, and you still have to build somewhat larger and more expensive cooling towers.?"
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I don't know, it just seems to me that geothermal could be incorporated somehow.

It seems that this may be a fixable problem. I'm not sure they addressed water usage when these plants were originally designed. Water boils at 212 degrees F (100 degrees C). The boiled water that turns the turbine would be in an enclosed loop. The mirrors could be adjusted to keep the temperature at only the maximum efficiency and no higher (i.e. some of the mirrors may not be used during peak sunlight hours). That way, the water temperature would only be raised high enough to create steam to turn the turbine, but not so massively high that the water would be hard to cool. It sounds like the water consumption is used to cool the water in the enclosed loop. Running the enclosed loop water through the ground (around 50 degrees F) would cool the enclosed loop water without using other water at all. A geothermal concept can be used for cooling as well as warming depending on where you live and the season. Maybe this wouldn't work but it seems like it would. Even in the desert if you go below ground far enough it is cool. All you would have to do is play with the steam and the water temperatures and try for maximum efficiency in this respect also.

To NeutronActivation:

The point of the article is not the consumption level of water between the thermal electric power industry and the agriculture one.
The agriculture is a monster compared to it.
The article does not focus on this.

It focuses on the water resources where these thermal solar power plants would be built which raises the water scarcity problem.
It suggests therefore to come up with better solutions like an effective dry cooling system.

"In a world where areas are experiencing life-threatening drought, freshwater resources should be fiercely protected. This doesn't have to be to the detriment of solar power--it just means companies need to do a better job of developing technologies that are not reliant on high water use. Continuing down the water-depleting road we're on is irresponsible and unnecessary."
From the link of the post.

http://www.ag.arizona.edu/azwater/awr/septoct08/d3aa3f8e-7f00-0101-0097-9f672482...

"Bahr says, 'Water use is one of the things to consider. If they are proposing to place [solar power plants] on undisturbed desert lands and pump groundwater where currently no groundwater pumping is occurring, we will give it more of a critical eye.' "

If this specific problem wouldn't exist than why would these companies bother to create new efficient water usage systems?

BULLSHIT ALERT!

According to the USGS Nevada uses 2 billion gallons of water A DAY for irrigation alone. That means these solar plants use less water in a year than agricultural irrigation uses in a day. Another thing to keep in mind is a lot of the water used to cool the current in-state thermoelectric plants is contaminated with different salts that make it unusable for other purposes. Even if they had to use fresh drinking water this water isn't "used up" after it cools the plant. After minor treatment this water would still be suitable for irrigation which is 80% of the states water use

Let’s Talk Water – Water Use
By Dr. Mike Strobel
How people use water really depends on where one lives. In many parts of the world, societies are not strongly industrialized and most water use goes towards human consumption and crop irrigation. In the United States, the largest water withdrawals were for thermoelectric power generation and irrigation. A USGS report on water use in the United States (http://water.usgs.gov/pubs/circ/2004/circ1268/) describes that 408 billion gallons of water per day were used in the U.S. in 2000. Of this total amount of water, ****about 195 billion gallons per day were used for thermoelectric power***. But much of this was saline surface water and represents water used for once-through cooling at power plants. About 52 percent of fresh surface-water withdrawals and about 96 percent of saline-water withdrawals went towards thermoelectric power generation. One could argue that because saline water is not available for other uses, such as drinking or irrigation, without expensive treatment, it shouldn’t count when considering how water is used in the U.S.

With that thought in mind, let’s look at how freshwater was used in 2000. Irrigation accounts for most freshwater use, at about 137 billion gallons per day in the U.S. in 2000, or about 40 percent of all freshwater withdrawn. California used the most irrigation water, about 30.5 billion gallons per day, or about one-quarter of the total irrigation withdrawals for the U.S. The next biggest user of irrigation water is Idaho at about 17 billion gallons per day in 2000. *****Nevada only used about 2 billion gallons per day in 2000******. Public water supplies (water for communities) were the second biggest use of freshwater in the U.S., with about 43 million gallons per day used in 2000. The big users were California, Texas, Florida and New York, where there are large populations living in urban areas. For comparison, California used about 6.1 billion gallons per day in 2000 for public water supply, whereas Nevada used about 629 million gallons per day for the same period.

http://nevada.usgs.gov/barcass/articles/Ely11.pdf

Figures the hippies would be sucking up all the water in an effort to be more "green". Wonder why that girl is wearing a hardhat? "The sky is falling! The sky is falling!"

Please tell us more. Give us specific numbers, because it doesn't all ring true. From what I know coal, and especially bitumen tarsands uses a hell of alot more water, and from solar projects I read about they reuse the water, they don't waste it. Don't see the NY Times complaining about coal though.

See one here:

http://current.com/groups/solar-energy/

And if people really care about water being wasted, then hydropower being made from unnecessary dams worldwide that have displaced millions of people, and caused environmental degradation and drought due to diversion from agriculture is much more important.

Thermal solar cells instead of solar cells in the desert... hmm.... simply put, that's really dumb isn't it...