The 'other' Achilles heel of coal

Coal plants, like nuclear, suck up lots of water during operation

Posted by Joseph Romm (Guest Contributor) at 12:03 PM on 13 Nov 2007

Read more about: energy | coal | water crisis

We've seen states like Kansas reject coal plants because of concerns the emissions will accelerate global warming. That's coal's biggest fatal flaw. We've also seen that nuclear power has its own Achilles heel in a globally warmed world -- water.

Now the Atlanta Journal-Constitution, in a major editorial, raises both the emissions issue and the water issue for coal. It questions whether now is the time to be building thirsty coal plants in a state where major water sources like Lake Lanier (see picture) are drying up:

Months before the drought had seized the public's full attention, the state Environmental Protection Division [EPD] granted permits for a new coal-fired power plant in Early County, a rural community in a severely depressed corner of southwest Georgia. But for a variety of reasons -- including mounting concerns about long-lasting water shortages and worsening air pollution -- state regulators ought to reconsider, or perhaps even reverse, their decision.

The drought has forced citizens and political officials to confront environmental concerns that are usually brushed aside. So, while Mother Nature has our attention, Georgia's leaders should think broadly about conserving all of our resources and expanding our energy portfolio.

Just how much water does the coal plant need?

... the plant is expected to consume nearly 20 million gallons of water a day from the Chattahoochee River, putting an additional strain on metro Atlanta's major source of drinking water. While the plant may be a boon to Early County, it could weaken Georgia's position in the ongoing "water wars" with Florida and Alabama over the disputed Chattahoochee watershed.

The paper notes that "The $2 billion Longleaf Energy Station they've proposed would sit on the banks of the Chattahoochee River, about 50 miles upstream from Florida." And further, "about two-thirds of Georgia's electricity is generated by coal-fired plants, such as Longleaf, which scientists say are contributing to global climate change." Yup, that is what scientists say!

The paper's startling conclusion:

It's true that rescinding EPD's approval of the Longleaf plant would be unprecedented. Nonetheless, the twin specters of continued drought and global warming have provided ample warning that the days of conducting business as usual are over.

The days of business-as-usual are over. The time to act is now. Kudos to the AJC for its bold call for change.

This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.

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3 Comments | Post a Comment

But there's always air cooling, they'll say

All steam generating (coal, nuke, gas) plants need cooling to condense the steam after it has passed through the turbines. Generally water is consumed in an evaporative cooling tower - the familiar tall concrete funnel you see attached to coal or nuke plants.

Cooling can easily be achieved without water - using air cooled heat exchangers. There is no technical problem with that, it is proven technology.

As a chemical engineer involved in the design & construction of large industrial plants I can tell you that clients and managers cringe at the mention of air cooling.

Air cooled heat exchangers are hugely expensive. If air cooling is the only option available it can sometimes put the capital cost of a project in doubt, especially for plants that need a lot of cooling (read steam generating power plant).

This is exactly why you don't see many large power plants with air cooling - it simply puts the economics of the project in doubt.

Heat can also be rejected from a power station into the sea or a river by circulating that water through heat exchangers and returning it to the source without consuming it by evaporation. This generally costs much more than evaporative cooling towers as it requires more expensive heat exchangers made from stainless steel etc. If capital cost doesn't kill this option, environmental regulations for how hot water can be returned to a river or bay probably will.

The great irony here is that the "free market" will generally kill a proposal for a new power station if it needs to be air cooled. Unless of course it gets subsidised by the government. Which is exactly what will happen to keep the coal barons happy.

by elbarto at 2:47 PM on 13 Nov 2007

Hmmm...

Interesting problem, considering the city of Atlanta dumps over 200 million gallons of wastewater a day into the river. I wonder if something else can be done with this waste water? Not to mention that although 30 million gallons a day sounds like a big number, it's just 0.2% of the river's flow.

Water can be a financial challange for new plants, as we use this cheap resource wastefully. But be careful in relying on it to stop coal, since it certainly isn't an insurmountable problem.

by Matt G at 11:48 AM on 14 Nov 2007

Whats the problem?

elbarto, you may have a limited view of the cooling options. There are a number of operating dry cooling power plants around the world. It's a proven technology. Yes it adds cost. Depending on the type of plant, the increase can be anywhere from 5% to 20%. However, that doesn't affect the economics since all thermal cycle plants are impacted and there is essentially no base load competition that is not similarly impacted. Other than economics, closed cooling is a big plus due to the enhanced water chemistry control.

The wastewater usage is a good point. The Palo Verde nuclear units in Arizona use spray pond (wet) cooling instead of dry cooling because of the availability of plenty of waste water from Phoenix.

by KenG at 1:21 PM on 14 Nov 2007

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