While I generally agree with that first, that last is not so. A not-inconsiderable part of it is converted to water vapor and dumped into the atmosphere. That's pretty much the purpose of these things:
Posted on 11/18/2007 4:46:29 AM PST by Oshkalaboomboom
As the historic drought worsens and the tri-state water battle escalates, Georgia policymakers are all but ignoring the region's biggest water guzzler.
Electric utilities are the single largest users of the region's freshwater. A family of four can use three times more water to power their home than they use to drink, bathe and water their lawn.
In Georgia, electric utilities use 68 percent of all surface water, the single largest user in the state, according to 2000 data from the U.S. Geological Survey, the latest year available.
"We've been working really hard over the years to tell people when they flip that light switch, the water is running," said Sara Barczak, with the Southern Alliance for Clean Energy, an advocacy group.
Yet the link between power generation and water use has been virtually ignored in the debate over how to fairly allocate the region's water resources and plan for growth.
Neither of the region's principal blueprints for water use — the state water plan and the North Georgia metro water plan — include strategies for managing water demand by the power industry.
Where does water come up? In the state's official energy plan. It quotes research that makes the connection: The public "may indirectly consume as much water turning on the lights and running appliances as they directly use taking showers and watering lawns."
Carol Couch, director of the state Environmental Protection Division, declined an interview request to explain why the state water strategy doesn't include conservation by the biggest water user. Kevin Chambers, an EPD spokesman, said utility water use would be discussed in the next round of planning, examining the specific water requirements in the state's 14 water basins.
Water flowing through Georgia and its neighboring states is controlled by the U.S. Army Corps of Engineers. To the corps, power generation is a top priority.
In Georgia, Alabama and Florida, most electricity is produced by Atlanta-based Southern Co., the nation's second-largest utility holding company with $14.3 billion in annual revenue.
Southern owns plants in all three states, which are locked in a legal battle over rights to much of the water the company uses. Southern has filed hundreds of pages of legal motions in the dispute, now in its 17th year.
Southern executives always come first in the pecking order when the corps holds its weekly conference calls to get updates on effects of the drought.
Last Thursday's call was typical.
The corps asked first for an update from Southern Co. subsidiary Georgia Power — before hearing from Georgia, Alabama and Florida officials, congressional staff or municipal drinking water chiefs.
The company had a quick report: "Our steam plants on the Chattahoochee are doing fine right now, thank you."
Water released as steam
With the drought bearing down, Southern has teams looking at ways to cut water use at every power plant in the region, said Jerry Stewart, an executive vice president who oversees non-nuclear generation. "They are trying to conserve all that they can," Stewart said.
Utility water use has escaped scrutiny, in part, because false assumptions have guided public policy in water planning. Utilities have argued for years that their use doesn't matter because they return virtually all the water they use.
But use does matter when drought shrinks the water supply, and consumption from other sources puts pressure on reservoirs and rivers.
A Southern Co. coal-fired plant in Florida or its Farley nuclear plant in Alabama may put at least half of the water used back into the Chattahoochee River. But that water isn't going back to Lake Lanier.
Power plants also require minimum river flows to keep operating. Low flows on the Coosa River forced Georgia Power to cut back energy output at one plant this summer.
On Friday, the Department of Energy convened a meeting in Atlanta with the Southeast's major electric utilities, including Southern and North Carolina's Duke Energy, to begin figuring out how they'll provide power if water levels drop too low.
Meanwhile, newer cooling technologies at power plants have increased the amount of the region's water that is actually lost through evaporation. The large clouds hanging over Alabama's Plant Farley aren't smoke, they're steam.
Stewart said calculating water use per unit of energy is tricky, and said Southern does not make those calculations.
Government agencies, however, have calculated that thermoelectric plants with once-through cooling use an average of 25 gallons of water to produce one kilowatt hour of power.
The average Georgia household burns 1,100 kilowatt hours of electricity a month. That translates to about 27,000 gallons of water.
By comparison, a family of four goes through about 9,000 gallons a month for household uses such as washing clothes, flushing toilets and showering.
Pressure on water supply
Cheap and abundant power is key to the Southeast's economic growth. But bigger demand for cheap energy is clashing with the availability of water, the state energy strategy warns.
"The pressures of a growing population and industries will tighten water supplies in more regions of Georgia, making even less water available for energy production," the report says.
Meanwhile, policymakers such as Gov. Sonny Perdue focus public outrage about the drought on environmental laws protecting mollusks in Florida, rather than the region's growing demand for power and its impact on water. The task of raising that issue has fallen to other players in the water war.
Alabama Gov. Bob Riley tried to make the point last month by holding a news conference about water rights outside Southern's Plant Farley. Perdue scoffed and talked mussels while Southern Co. stayed away from Riley's news conference, keeping its head down.
When Barczak came to Georgia eight years ago, she said, state officials repeatedly told her to ignore water use by the power industry, saying it returned what it used.
"Then when I really looked into the numbers, it was, like, 'No, that really isn't the case,' " said Barczak.
In water terminology, use refers to water withdrawn from a water source; consumption refers to water that is lost, usually to evaporation.
In 2000, electric plants in Georgia — almost all owned by Southern Co. — withdrew an average of 3.3 billion gallons per day, more than half of all the surface and ground water used in the state, according to the geological survey.
People and utilities demand more water and power in the summer, especially during a drought.
In August, power plants in the Appalachicola-Chattahoochee-Flint river basin withdrew an average of 875 million gallons a day, according to Georgia Power.
Metro Atlanta, using the same river basin, withdrew 510 million gallons a day.
Water goes up in smoke
Georgia Power's oldest plants use once-through, or open loop, cooling systems to condense the steam used to generate electricity. The water flows in one end of the plant, condenses steam into water, and then returns to the river out the other end.
The quantities of water required are enormous – up to 500 million gallons a day for a medium-sized coal plant. In Georgia, the thirstiest plant uses more than double that.
Coal-fired plants employing once-through cooling use up to 27 gallons of water to generate one kilowatt hour of electricity, according to the federal Department of Energy. Nuclear power plants use more than 31 gallons for the same output.
Georgia Power must report to state environmental officials how much water its plants consume during the heat-exchange process.
For plants that use once-through cooling, Georgia Power reports zero or negligible water loss because the water is returned to the river.
The reporting, however, fails to account for millions of gallons of water that disappear as vapor once the hot water from the plant returns to the cooler water in the river, a phenomenon known as downstream evaporation. Southern's Stewart said such losses are minimal.
But the Electric Power Research Institute, a Washington research group supported by the nation's largest power companies, estimates significant water loss, as much as two-thirds the amount evaporated from newer, recirculating systems.
The Energy Department estimates that thermoelectric power generation in the United States could consume more than 9 billion gallons of water a day by 2030, three times the amount consumed in 1995.
Georgia Power's newer plants no longer use once-through cooling systems because of environmental concerns. The newer plants recirculate cooling water in closed-loop systems, sending hot water from the condenser to be air cooled in tall towers. These reciruclating cooling systems withdraw a fraction of the water used by once-through systems.
But recirculating systems lose much more water to evaporation — about a half gallon of water for every kilowatt hour of electricity, according to the energy department. Over time, Georgia Power has been replacing older once-through systems with recirculating ones.
Georgia Power's Plant Yates, located on the Chattahoochee River in Coweta County, once used about 477 million gallons a day — more than the average daily requirements of metro Atlanta. After switching to cooling towers, its water use dropped to about 32 million gallons a day.
But the plant lost 51 percent of that, or about 16 million gallons, to evaporation and "blowdown," a process that periodically flushes mineral deposits and slurry out of the cooling towers.
While roughly 80 percent of the evaporated water returns to the atmosphere as vapor, it doesn't return to where it was withdrawn. It drifts away, coming down as rain elsewhere.
Conservation is key
The best strategy for reducing water use, environmentalists say, is to reduce energy consumption, which is rising sharply in Georgia. According to Georgia Power, the average consumer used 13,216 kilowatts a year in 2006, up 11 percent from 1996. On average, consumer electricity use grows 1.5 percent a year.
A study paid for by the Georgia Environmental Facilities Authority, the state's energy planning agency, found that aggressive statewide conservation could save 164 million gallons per day by 2015. Most of that savings — 159 million gallons— would come from slowing the rate at which power use grows.
The numbers put conventional water saving measures in perspective. "It's important for us to use low-flow shower heads," Barczak said, "but the real savings can come at the electric utilities."
Please look here:
http://www.windows.ucar.edu/tour/link=/headline_universe/small_feb.html&edu=high
Or here:
http://csep10.phys.utk.edu/astr161/lect/comets/smallcomets.html
See post Number 21.
This seems like a dated postulate. Do you have anything more current that has withstood peer review?
They arrive every minute and my peers have reviewed them.
Small comet theory melts under scrutiny
http://www.sciencenews.org/pages/pdfs/data/1998/153-23/15323-07.pdf
UI researcher fails to detect small comets
http://news-releases.uiowa.edu/1999/december/1216mutelcomets.html
‘Snowball Comets’ Are Just Camera Noise, Berkeley Researchers Say After Analyzing Dark Pixels In Iowa Data
http://www.sciencedaily.com/releases/1998/09/980910074516.htm
That settles the matter. Who could question a self declaration of acknowledged scientifc fact, even if it is shrouded in obscurity and skepticism?
However, as you said your peers reviewed the theory. What is your area of scientific endeavor?
The latest new at the site you linked is 2001. Most of the news is from the late 90’s, the same time period as my links.
Per unit of energy output, yes, a nuclear plant uses more water than a coal plant.
While I generally agree with that first, that last is not so. A not-inconsiderable part of it is converted to water vapor and dumped into the atmosphere. That's pretty much the purpose of these things:
See my previous post.
Without getting into the details of the thermodynamic cycle involved, there’s a huge requirement for condenser cooling water with coal or steam plants. Even with recirculating systems using cooling towers, the make-up requirements are pretty enormous for a big plant.
From your link: “With all of this evidence in support, it does appear that there are about 20 snow comets weighing 20 to 40 tons each that crash into the Earth’s atmosphere every minute. The comets are no danger to life on Earth because they disintegrate in the atmosphere.”
20 per minute x 60 min/hr x 24 hours day = 28,800 per day x 365 = 10,512,000 per year.
That means 10,512,000 20-40 ton snow comets entering the Earth’s atmosphere earth each year magically avoid our orbiting satellites and space craft. Figure in nearly 50 years of space flight and we’ve avoided almost 1/2 billion, 20-40 ton missiles. Damn we’re good.
If you think the evaporated water DOESN'T get back to the watershed you're an idiot. Read the article, such heat exchangers "use" 1/10th of what a once-through water-to-water unit does. And even THAT gets returned eventually.
No--this whole issue is due to the fact that Atlanta failed to build reservoir capacity to match population growth.
First: Keep a civil tongue in your head.
Second: You are mistaken again. It is entirely possible for that water vapor to migrate out of the area defined as the watershed, without it being precipitated out. If fact, very possible. With the prevailing winds here, it often ends up over the Atlantic.
I agree on the reservoir capacity issue.
Sure, some miniscule amount probably does---but that amount is completely insignificant relative to the amount of water continually being cycled in and out. And I'd bet that 90+% of it DOES remain in the watershed area.
Blaming the power companies for Atlanta's water shortage problems is so over the top that anybody who does it IS an idiot. You decide where you fit.
>>And I’d bet that 90+% of it DOES remain in the watershed area.
Have you bothered to look at the rainfall amounts since, say, last Winter? Hint: There hasn’t been a whole lot of precipitation happening.
I expect you are sadly mistaken on this point, at least for the period of interest.
And point out where I’m “blaming the power companies”, as you weakly attempt to imply. I never said any such thing.
But keep up your wrong-headed obnoxiousness, it seems to suit you well.
If the Solar System is has so many snow comets, why is Mars and the Moon with little to no water?
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