How Much Water Does A Power Station Use?

I don't think "use" is an appropriate term because it implies that they consume the water.

Power plants use water for cooling. The water they cool with is usually drawn from a nearby body of water (river, sea) and most of it returned directly or as water vapor from a cooling tower.

This is in stark contrast to the water contamination that apparently happens with a hydraulic fracturing setup.

- Chris

 

A large power plant as noted by css28 uses water for cooling which could approach 500,000 gallons per minute. If it has a cooling tower depending on weather and temperature water vapor release may be in the range of 25,000 gallons per minute. Of course eventually that water will return as rain.

 

The cooling water recirculates, but eventually evaporates. Some of the excess heat is transfered by direct conduction, but most goes out through evaporation. The specific heat of vaporization for water is 540 calories per gram, so knowing the capacity and efficiency of a power plant you can get a good estimate with that number.

Tom

 

The plants also use water for steam to drive the turbines, but it isn't just dumped down the drain. Most of it is condensed by the cooling water and returned to the boiler.

Unless the plants are at the head of a river or using a reservoir, I don't see how their cooling water use has much affect on municipal water supplies.

 

Believe it is possible to design an ultra-clean natural gas power plant that does not use much if any cooling water. However, this is probably more expensive so more commonly you will see cooling water on big plants. It is possible to use gray water which is treated municipal waste water.

Not sure what your TV station was trying to say, if there is competition for drinking water supplies then need to start using gray water and designing power plants for less water use.

 

The power plants that produce my electricity use a LOT of water. In fact, they use nothing but water.

 

LCRA, the state agency that governs the water in my region, successfully blocked a coal power plant, but not permitting them a permit for the quantity of water they would use. It does not all go back in the river Our environmentally challenged governor would have stepped in I'm sure if their wasn't validity to water conservation in this region. Coal uses more water/kwh than natural gas and windmills only use water when they are being manufactured.

This is a river/reservoir situation, but the plant would affect quantities down stream. The nuclear plant I get power from is near the end of a river, and the water turns brackish downstream, so that was not an issue when it was built. Nucs cause a great deal of heat pollution changing the ecosystem near the water they use.

 

That is common for nuclear plants, either on a river or a lake, or draining into the ocean. It's not coincidence that Japan built many of its nuclear plants along the ocean.

Ethanol plants also use a lot of water. When ethanol was being heavily promoted, there was debate in the rural areas where the plants were being built, as they might use as much water as the whole rest of the county. I think they came up with some ideas to reduce that a bit, but it still uses a lot of water.

Unfortunately, I don't have good numbers for GC.

 

Power plants don't consume much water. They utilize a lot of water, over and over and over again. For the most part it's the same water being continually heated and condensed. Hydro-electric plants don't consume any water. They simply make harness the energy that would otherwise be wasted as gravity moves the water downstream.

 

People concerned about conserving water and the environment should adopt a vegan lifestyle.

One pound of beef requires an input of approximately 2500 gallons of water, whereas a pound of soy requires 250 gallons of water and a pound of wheat only 25 gallons. Meat production is inefficient as it requires the consumption of an extensive amount of resources over many months and years before becoming a usable food product. With the water used to produce a single hamburger, you could take a luxurious shower every day for two and a half weeks.

The specific numbers vary from source to source, but the trend stays the same.

 

The details a new coal plant -

White Stallion near Bay City TX. Proposed 1,200 MW coal powered plant, needing to contract 25,400 acre-feet of Colorado River water, or about 8.3 billion gallons per year, an amount equivalent to 15 percent of Austin's annual water consumption. It was estimated that it would have produced about 10 million tons of CO2/year also.

That is a lot of water by any measure, and we have a lot of people and crops that need it more than the coal does. The state was going to let it go through but then drought years happened reminding them that in the 1950s there just wasn't enough water to go around.

Yes, the difference is South Texas Power is not in a earthquake zone, is well above the flood plain, and is built to higher standards than other us nuclear plants. They built it, when the congress had made it illegal to build natural gas for base load, which made the choice nuclear or coal.

Ethanol also takes up a great deal of water to raise the corn. Hopefully the numbers above will help GC out.

 

Thermoelectric-power Water Use, the USGS Water Science School

teaches about this. Please do not be deterred that it is aimed at school kids. We have just as much right to learn things as they do

 

You are correct. The difference in most power plant water is that it does not go through water treatment. However, it still uses water from the same sources that a lot of municipal water is coming from, depending on where the plant is located. If those sources are being depleted, then big problems are imminent.

Out in CA, there is a big bottleneck of putting power plants inland. The following link shows how a new solar plant must use less efficient air cooling, since water cooling is just not possible.


Update from Ivanpah – April 2012 | Brightsource Ivanpah


Scroll down to the condenser tower photo to see how cooling must be done in the desert.

 

Absolutely true!

I introduced this point here once a while back, and boy, oh, boy, did the Prius drivers ever complain! They're delighted to save a little gas by driving their Priuses, but they don't want to hear about the environmental effects of farming meat.

(I had actually read lower numbers, but the same relationship: ten times the land and 100 times the water to produce meat compared to an equivalent amount of vegetable protein.)

 

Water is used in several ways in a power plant:
- To produce steam to turn the turbines that produce electricity.
- To cool equipment by absorbing the waste heat produced by power generation. This is done with either once-through or closed-loop cooling systems. Closed-loop systems reuse water rather than returning it to the source.

Each kilowatt-hour (kWh) of generation requires the withdrawal of approximately 25 gallons of water, primarily for cooling purposes. That's what must be withdrawn - they actually consume far less. That consumption is caused by evaporation. On average, 2 gallons of water are lost to evaporation for each kWh consumed at the point of end use, though this number varies greatly due to many factors. In a dry climate like Arizona almost 8 gallons of water are lost to evaporation per kWh consumed.