Water Used in Generating US Electricity

In my four-article series on water use (The Resource Matrix), I took you on a journey to reveal the layers of The Resource Matrix in order to help you understand how water will be a highly contested commodity tomorrow, possibly as much as oil is fought over today.

You learned about your water footprint and a website where you can calculate it, virtual water and virtual water transfers, whereby choices here affect water availability elsewhere, to the point of some people not having enough water to drink in order to produce inexpensive dyed cotton, along with insane choices such as growing crops in the desert.

You learned that on average it takes 1854 to 3000 gallons to produce one pound of beef.

Yep, it’s it’s been a great journey through the sidetrip city of the Resource Matrix.

Today, we’ve found the on-ramp to the Green Lighting Interstate and are driving to take a look at water use in generating electricity.

For a simple reason. It takes a lot of water to produce electricity.

How much? 5% of all US water? 10%? Can’t be as high as 25%?

Electricity and water?

I thought the issue was fossil fuels and greenhouse gases

The U.S. Geological Survey (USGS) estimated water use in the United States in 2000.

Their grand total: 408 billion gallons per day withdrawn for all uses.

The number 1 spot, weighing in at 48%, was thermoelectric power.

Irrigation earned the runner-up prize at 34%.

The 195 billion gallons need to come from somewhere, and actions have consequences. Environmental ones, as in 40 million fish in the Great Lakes killed each year due to being trapped against water intake devices. That’s a lot of Friday night fish dinners.

How much water is used in generating electricity?

Large fossil fuel and nuclear plants require incredible quantities of water for cooling and ongoing maintenance.

Water for thermoelectric power is used in generating electricity with steam-driven turbine generators. It uses 48% of all water in the US.

According to the Pace Energy and Climate Center, the amount of water used for power plant cooling varies by each specific power plant’s electricity generating technology and size. Nuclear reactors require the most water for cooling, and baseload fossil fuel power plants come in second.

The Salem Nuclear Generating Station alone takes 3 billion gallons a day from the Delaware Bay, according to the Pace Energy and Climate Center.

Nationally:

• Steam electric generating plants across the nation draw in more than 200 billion gallons per day.
• Nuclear and fossil fuel power plants drink over 185 billion gallons of water per day.
• Geothermal power plants add another 2 billion or so gallons a day.
• Most renewable energy technologies require little or no water for cooling.

These numbers are starting to sound like the same ones the U.S. Treasury and Federal Reserve Bank use.

Imagine watching your favorite science program where astronomers explain that the universe is 78 billion light-years wide (78 billion units of 5,878,630,000,000 miles). There is absolutely nothing in our experience to help us wrap our mind around it.

How much is 3 billion gallons per day?

The Delaware Bay feeds Salem Nuclear Generating Station 3 billion gallons a day.

Imagine this rectangle: a football field with end zones (360 feet long x 160 feet wide). Then add to it walls on each side of the rectangle to create a container to hold the 3 billion gallons you pour into it.

How high do you need to make those walls to contain 3 billion gallons? 6915 feet high. Or 1.3 miles.

Maybe 6915 feet high is still hard to imagine. So how deep do you cover the field in order to feed the Salem plant every minute? Answer: 5 feet deep. Every minute.

48% of all water use: We’re Number One!

How much is 195 billion gallons per day?

Using the USGS figure for 2000, thermoelectric power nationwide used 195 billion gallons a day, or 48% of all water used in the US. My guess is the water use has grown since then.

How high are the walls on our football field now? 449,475 feet or 85 miles high. We’re back to US Treasury and astronomy numbers again.

So, let’s get a higher-level view to help us.

Lake Erie holds 116 cubic miles of water.

Nationally, thermoelectric power uses 195 billion gallons a day - or 64.2 cubic miles a year.

We drain Lake Erie every 22 months.

But the water used is returned to its source.

So what’s the issue about water use?

Power generation returns 98% of the water back to its source (bay, lake, river, ocean).

It’s the environmental consequences.

The Pace Energy and Climate Center explains it neatly:

Withdrawal of large volumes of surface water for either power plant cooling or hydropower generation can kill fish, larvae and other organisms trapped against intake structures (impinged), or swept up (entrained) in the flow through the different sections of a power plant.

Examples include:

• The Salem Nuclear Generating Station is responsible for an annual 11 percent reduction in weakfish and 31 percent reduction in bay anchovy.
• At the Indian Point 2 and 3 reactors on the Hudson River, the number of fish impinged totaled over 1.5 million fish in 1987.
• The 90 power plants using once-through-cooling on the Great Lakes kill in excess of 40 million fish per year due to impingement. (Once-through cooling needs a continual flow of new water, and uses 30 to 50 times that of a closed cycle system. Closed cycles cool down water from steam then reuse it.)

The diversion of water out of the river removes water for healthy in-stream ecosystems:

• Stretches below dams are often completely de-watered.
• Fluctuations in water flow from peaking operations create a “tidal effect,” disrupting the downstream riparian community that supports its unique ecosystem.
• A dam’s impoundment slows water flows, which hinders natural downstream migration of many fish species.
• By slowing river flows, dams also allow silt to collect on river and reservoir bottoms and bury fish spawning habitat. Silt trapped above dams accumulates heavy metals and other pollutants. Disrupting the natural flow of sediments in rivers also leads to erosion of riverbeds downstream of the dam and increases risks of floods.
• The impoundment of water by hydropower facilities fundamentally reshapes the physical habitat from a riverine to an artificial pond community.
• This often eliminates native populations of fish and other wildlife.
• Dams also impede the upstream and downstream movement of fish and other wildlife, and prevent the flow of plants and nutrients. This impact is most significant on migratory fish, which are born in the river and must migrate downstream early in life to the ocean and then migrate upstream again to lay their eggs (or “spawn”).
• As mentioned above, withdrawal of water into turbines can also impinge or entrain significant numbers of fish.

The cleanest kilowatt is the one never used:

Back to those compact fluorescent lamps and LEDs

PowerScorecard.org explains the solution:

By re-directing electricity dollars to support environmentally benign energy resources, consumers are empowered, in states that offer supply choice, to influence the existing generating resources that are deployed to meet demand.

They can also support the construction of new and cleaner electricity resources that will be built to meet overall growth in demand in the future. By supporting these power options, consumers can minimize many water use and consumption impacts. Still, directing your dollars to cleaner power products in no way helps remediate damages that already have occurred. Consumers can stop the construction of new hydropower facilities or alter conditions of siting and operation, but they cannot undo previous environmental degradation that occurred at existing hydropower facilities.

In short, reduce your use of electricity.

More Info:

We used several sources for this article, including the PowerScorecard.org website, which is produced by the Pace Energy and Climate Center, which is part of the Pace University School of Law’s Center for Environmental Legal Studies, Pace University, White Plains, New York.

On PowerScorecard, you can get:

• Ratings of Electric Power Choices for some service areas.
• More info on electricity and the environment:
  • Technologies
  • Climate change
  • Acid rain
  • Ozone depletion
  • Water use (our article today)
  • Water quality
  • Land: on-site and off-site impacts

Thanks for letting us keep you updated . . .

To your green, brighter future,

Cinnamon Alvarez,

A19

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