(John Weeda) There are two things that are important to locating a power plant, one is a fuel source, and the second is water. (Carl Bauer) Energy is as big a user of water as agriculture and they’re the two largest users of water in the United States. The energy business is a huge consumer of water, and we need more energy, which means we need more water. The world is reaching a situation with constant growth of population and a diminishing resource of good water.
The clean water is becoming increasingly hard to find.
You really have to understand the bigger picture so that you can know what those choices are, what the trade-offs are. [synthesizer plays in bright rhythm] (man) Funding Provided by the U.S. Department of Energy, The National Energy Technology Laboratory, The Energy and Environmental Research Center’s Northern Great Plains Water Consortium, and the Members of Prairie Public (female narrator) Modern life is built on access to affordable energy– at home, at school, at work, and just to get around. But it takes more than pumping oil, harvesting wind, or digging coal to provide energy.
It takes water. We may fret in the United States about running out of oil, but the water lubricates the American economy just as oil does. (narrator) Water plays a role in everything we do, whether it’s turning on the tap or flipping the switch.
The energy business itself is a huge consumer of water and we need more energy, which means we need more water. So what you have is a finite supply, and then you have increasing demands.
As we’ve increased the amount of energy we produce and consume as well as our needs for increased agriculture, we now find ourselves trying to get more use out of the same drop of water. (narrator) To meet future demands, we’ll have to rethink how we use water and where we get it. Across the nation, energy companies and local governments are already taking creative actions to conserve and reuse water. The history of energy is really a story about water. For hundreds of years, humans relied on the energy of flowing water to turn a wheel.
And the wheel supplied the power to grind wheat, saw logs, or weave cloth. In the 1700’s, steam joined the workforce in pumps developed to get the water out of coal mines in England. By the mid 1800s, improved steam engines were at work on land and sea while mill wheels continued to provide the energy to grind flour and run machinery. After the American Civil War, traditional mill wheels gave way to turbines– fanlike wheels that could harvest more of the energy from running water.
In 1882, Thomas Edison combined the steam and the turbine with a generator.
The product was electricity to power streetlamps in New York. And that was the dawn of the modern age. Nothing defines our modern lifestyle like our use of energy– for transportation; for heating and cooking; for light and power. And that energy production depends on water. Water is essential in making gasoline.
Even harvesting energy from renewable sources requires water. Today, steam is still used to generate 90% of our electricity. But that means water for steam, water for cooling, and water for cleanup. The steam-based power plants are the ones that use coal or natural gas or oil or nuclear all need water for the steam cycle. So they’re pushed to be near large bodies of water, whether it’s on the coast using ocean water, on rivers, on lakes to provide the water– water goes into the boiler; heat from combustion makes steam from the water; that steam goes down a pipe to a steam turbine; causing the turbine to turn, then it turns a generator; the generator actually makes the electricity.
(narrator) Once its pressure is used up, the steam goes back to the boiler. On the way, the steam is cooled into liquid water in a condenser so that it can be pumped back to the boiler. The condenser is like a huge radiator. But where the radiator in a car uses air, the condenser uses cold water. Cool water runs through the condenser within thousands of tubes.
The steam passes around the outside of those tubes and is cooled and condensed back to water. (narrator) The cooling water gets heated as the steam is condensed. Before it can be reused, the water needs to be cooled down. In some plants, that happens in a cooling tower– a structure containing many series of waterfalls that cool the water by evaporation. In other plants, the heated cooling water flows to ponds where its heat is dissipated.
In the case of one power plant, Milton R. Young Station, the cooling water comes from a man-made reservoir, Nelson Lake. The temperature of our lake, it’ll get up to about 95 in the midsummer.
In the wintertime it doesn’t go below freezing. (Craig Bleth) We cycle that water through the plant at a rate about 368,000 gallons a minutes which is the number that is hard to get your arms around.
(narrator) The plant uses the same amount of water every minute as two households in an entire year. Condensing steam to a liquid is the biggest use of water in a thermoelectric plant.
Whether it’s coal for electricity or oil for gasoline, water goes into energy production. Although the spotlight has recently focused on the water needed for hydraulic fracking, the vast majority of water consumed in the oil and gas industry is divided between traditional forms of oil recovery and what happens at the refinery. Water is an absolutely critical aspect of the refining process.
Refiners are generally located along the major water sources. Tesoro takes about 1,000,000 gallons of water out of the Missouri River a day. It uses water for a number of different processes; creating steam, desalting the crude oil that’s coming in, and certainly to run their boilers. The great news about Tesoro in North Dakota is that they have a natural water filtration system in which they return about 400,000 gallons a day into the Missouri River, actually a higher quality than it comes out. (narrator) It takes 3 to 6 gallons of water to make a gallon of gasoline.
And almost a gallon of water for every kilowatt hour of electricity. In fact, Americans use more water running lights and appliances than running the faucet. Are alternative energy sources more sustainable when it comes to water? People don’t always realize as we look at our renewable energy issues that there is a water element in most of them.
(Robert Glennon) Even in a new ethanol plant that recycles its water, it takes 4 gallons of water to refine 1 gallon of ethanol but that’s a preverbal drop in the bucket compared to the water it takes to grow the corn.
Now, if you are in an area where you can count on Mother Nature to provide enough rainfall, well, it’s coming from the sky, that’s not a problem. But the moment you get into areas that irrigate, then it becomes a big problem because that’s water that could be used for other crops. (narrator) Solar energy captures the power of the sun with photovoltaic cells and using thermoelectric power towers. When you’re out there where there is high solar it’s often a dry climate so you have to keep the mirrors if you’re using solar thermal, or photovoltaic cells, keep them clean so they can maximize their production of electricity, reflect the sun on to a boiler. And by the way, the thermal solar where you take the sun and you focus it on a generator of steam, again and you’re in the steam cycle, and again you need water to cool that, In fact, solar thermal generation is one of the largest consumers of water per megawatt of any of the sources and nuclear power is then second to that.
Even hydro takes evaporation water, if you have Lake Mead sitting there in the desert; you have an enormous evaporation loss every year off that, so you’re not using water in the cooling plant but your using water by having evaporation. (narrator) Wind takes the place of steam to turn the blades of the turbine to make electricity. But what happens on a calm day? Unfortunately you can’t store electricity so when you turn the light on and want it on somebody out there is generating that power instantaneously. (narrator) Right now, there is no commercial way to store electricity, so no matter the source, having reliable energy means using water!
Thermoelectric generation alone uses 40% of our water. Agriculture takes another 40% for livestock, fish farms, and to irrigate our food crops. The last 20% is shared among households, businesses, and industry. In our modern world, it takes water to have energy. But it also takes energy to supply water.
For most of us, turn on the tap, and the water flows. A family of four in the United States uses about 400 gallons of water every day– enough to fill the bathtub 7 times.
For the 86% of us who depend on the public water supply, we don’t have to think about where our water comes from, or the equipment and energy it takes to make it available. The cost of water is about 40% or 60% energy– electricity or natural gas pumps moving it through the pipelines, treating the water, and then the variation is really how far you have to move it. Most large cities throughout the United States do use surface water because of its volume that’s available.
We pump the raw water into the treatment plant through a number of processes– it’s pretty energy intensive. (narrator) After the water is treated, large electric pumps push the clean water to homes and businesses where it is either used or consumed. Most of the water we use in our homes goes down a drain, to the sewer and eventually back to the river. When we talk about water usage, that is water that we use to bathe, to clean our dishes, wash our clothes. That water all has to be pumped up to the wastewater plant and treated to a quality that’s better than the river water itself.
(narrator) From well or river, energy moves water from source to tap to treatment to discharge. The amount of electricity needed every day to supply water to a family of 4, could run a refrigerator for 9 hours. But that’s only part of the story. When we water our lawns or gardens, that water is lost to evaporation and is not available to users downstream. This water has been consumed.
Even though thermoelectric plants need a large volume of water for operation, very little is actually consumed.
In fact, as far as water withdrawal–not consumption– energy is as big a user of water as agriculture. However the energy use does not consume the water. A lot of the water that it uses goes back into the river or lake that it came from. (narrator) Usable water is a limited resource.
Only so much falls on the land, only so much flows in rivers, and only so much is stored in the ground. The world is reaching a situation with constant growth of population and a diminishing resource of good water.
The clean water is becoming increasingly hard to find. (Robert Glennon) What we need to do is this, If you want to put a new straw into the milk shake glass, then you need to pinch someone else’s straw, you need to persuade someone else to make do with less– and that’s happening. (narrator) Making do with less is bringing cities and energy companies together as they look to the future.
Across the United States, good water stewardship is paying dividends. Gerald Gentleman station runs 24-7 to meet the electricity need for homes and farms. (Brian Barels) Gerald gentleman station here provides electricity to approximately 1.3 million households within Nebraska. We have a large number of groundwater irrigators.
Groundwater irrigating provides a significant demand for electricity during June, July, and August. And we have seen that demand be somewhere in the neighborhood of 600 megawatts or slightly above. (narrator) That demand for electricity to pump the groundwater for irrigation is half the power the station can generate! Gerald Gentleman had to make a decision.
Build another plant to meet this seasonal demand and increase their water consumption, or ask their customers to be part of the solution.
It is a very significant load that occurs at the highest time of electrical demand. They need water for their crops the same time we need to cool our buildings and cool our home, right about 6:00 in the evening. We found that if we can ask them to hold off and irrigate a little later in the evening that we can meet all those demands without having to have another power plant in place.
In fact, some days of the year we actually have our peak power demands somewhere around midnight. It’s really a conservation program that is able to reduce our demand at peak times about the size of one of the units at Gerald Gentleman station.
(narrator) In neighboring Colorado, the growing population is demanding more electricity. In an area with a limited supply of water, Comanche station is responding with technology to double their electricity generation without doubling their need for water.
Comanche Unit 3 along with 1 and 2 are all coal-fired power plants, they burn Power River Basin coal. 1 and 2 are roughly 350 megawatts, Unit 3 is 750 megawatts. Water is obtained from the Arkansas River, that water is pumped to the site, stored in a pond on site.
We have drought years out here so during those drought years we have to cut back on water use. (narrator) To get permission to build Unit 3, Comanche Station had to find a way to use less water. Their solution was to install two condensing systems: traditional water cooling and an air-cooled condenser. For most of the year, the chilly Colorado air is adequate to condense steam. (Tim Farmer) The air cooled condenser, it’s in A-frame.
So if you think of an A-frame type cabin– in the top of the roof is where the steam comes down; it goes down the sides of the roof.
The air is coming up from below, goes through that roof, cooling off the steam. And the condensate is collected down off the bottom of the roof and that goes back into the cycle. We could operate Unit 3 with just the air-cooled condenser. In the wintertime we could probably still sustain full load on the system, in the summertime, it’s gonna drop off significantly.
We’d probably be lucky to be at half load just on the air-cooled condenser on the days when we’re up in that 90-degree range. (narrator) During the hot summer months, air cooling is just not enough. Comanche uses traditional water cooling to finish the job. Comanche Unit 3 is the largest parallel cooling system in the world today. It’s a higher capital cost, but we went to that type of system to get as much output on that unit while conserving water.
(narrator) With the combination of the air and water cooling, Unit 3 consumes less than half the water of the other units. The older units have been retrofitted to use less water too. (Ruben Roman) We use water for the boilers. We use water for multiple systems, so there’s no way we can operate without water, but we started to do a lot of things with our operational practice, then just changing where equipment drained to and where water went to so we could reuse it. We’ve become much more environmentally conscious in doing things to minimize water use, to maximize reuse and to be conscious of not just using because it’s there.
(narrator) Coal might be used to make the steam in most U.S. power plants, but in North Dakota, Great River Energy is showing that the coal itself is a source of water. (John Weeda) The coal in North Dakota is lignite coal. Lignite is a lower quality coal.
If you go through the rankings, there’s peat that’s a real low quality then you have lignite, subbituminous, bituminous, anthracite.
Each one has less moisture. So lignite is a low-heat content, high moisture coal. (narrator) The lignite at Coal Creek is more than 35% water. (John Weeda) It takes energy to heat all that water up.
If you take the water out of the lignite before you burn it, you don’t have to heat up all that water. Here using the waste to heat, to dry the coal and improve the efficiency is really the key to this technology. The 4% efficiency improvement we get from dry fine is really exceptional.
As soon as we started putting dryers in service last winter; you saw the amounts of coal per megawatt hour produced started tailing off right away. So you could see that efficiency improvement.
(narrator) The water from the lignite can be put to other uses. (John Weeda) This is a source of good clean water. We use it as part of our cooling water. Again, it’s a good use of resource trying to conserve wherever we can. (narrator) Collaboration and technical innovation aren’t limited to electric utilities.
Cities have to clean up their water for discharge because that water goes downstream for the next city’s use. In Mankato, Minnesota, collaboration is making treated wastewater a resource.
The city generates about 7 million gallons per day of wastewater. Some of that is from the city of Mankato. We also treat the wastewater for other municipalities.
(narrator) The city of Mankato was looking for a way to finance improvements to its wastewater treatment to meet environmental regulations. Calpine, an electric utility, was looking for a source of cooling water. (Mary Fralish) Several years ago, Calpine located Mankato as an area where they wanted to build a power plant. Their potential sources of water included the Minnesota River, the Mount Simon aquifer. The biggest need for us was to have a source, not groundwater, that we can actually use for our cooling needs here at the plant.
(narrator) Mankato’s treated wastewater could be that source.
Aware of the need for improvements to the wastewater treatment plant, Calpine partnered with the city of Mankato by financing the cost of the improvement in exchange for a supply of cooling water. (David Jacobs) We could have built a station a quarter-mile from the Minnesota River. However with the needs of the city, we decided it would be make good sense to invest in that project in order to bring us a water source because this is a good fit for us. We bring the water from the city down the pipeline into the cooling tower itself.
Then once we are done with the cycle of cooling tower, we’ll send back about 150 to 300 gallons a minute to the city. It goes to their discharge pond, their discharge basin, and it’s either blended into their process or discharged straight to the river. (Mary Fralish) Out of our 7 million gallons of wastewater that we generate each day, the Calpine power plants is taking about 1 million of those currently. They didn’t have to get any further regulations for taking water out of the Minnesota River or discharging it. The benefit to the environment is that we are reusing that water rather than taking it out of our Mount Simon aquifer.
(narrator) Mankato is just one example of how sharing water between consumers can reduce the demand for more water. The city of Los Angeles has struggled to meet demand for more than a century, going farther and farther afield to get water for its ever-growing population. Today, reuse and conservation are helping the city make better use of the water it already has. The Departmental of Water and Power serves the entire population of the city of Los Angeles, just over 4 million people. LA gets its water from 4 primary sources.
Over 85% is imported. That’s from 3 sources, from the Colorado River, from the eastern Sierra, and from the western side of the Sierra’s through the Bay Delta area. The remaining water is groundwater from the city of LA (narrator) Years ago, the city tapped the last available sources of fresh water. Now, Los Angeles is starting to squeeze more use from the water it has. Instead of discharging millions of gallons of treated wastewater to the ocean, Los Angeles is recycling it for new uses.
We take the tertiary treated water from one of the Bureau of Sanitation wastewater treatment plants, and we then pump it for irrigation or industrial uses such as cooling towers.
We currently recycle just over 1% of the water used in the city of LA. (narrator) Conservation and recycling have held the line on water use. (Jim Yannotta) Even though LA increased in population by over 1 million people we still use the same amount of water that we did as of about 20 years ago. (narrator) Las Vegas– casinos and resorts, fountains and golf courses.
In the 1920s, the Las Vegas valley was a desert with a few thousand hardy souls. Now, it’s home to millions. An oasis based on water stewardship. (Doug Bennett) Through the 1980s, the growth was explosive here. One of the biggest challenges is, how to we meet the continued growth of this community?
The precipitation from these mountain ranges around the Valley produce enough runoff and infiltration into the groundwater basin that that can sustainably supply 10% of our water needs. The other 90% is drawn from the Colorado. 60% of our water goes to what we call consumptive uses. If we use it outside of a building, it’s evaporated into the atmosphere. You consumed it; you used it up as far as the resource supply was concerned.
If you use it in a building it goes down the sewer system, it gets treated to tertiary standards, and then it gets returned to the Colorado River.
And we get credit for that. The resorts use very little of their water outdoors. The entire resort sector accounts for 7% of the water that’s delivered in this valley. Less than 25% of that water is used consumptively.
What would really surprise people is that the air-conditioning in those buildings uses more water than the landscaping, swimming pools, and water features combined. (narrator) Where water is used outside, more thoughtful planning and programs like converting lawn to drought-tolerant plantings help reduce consumption. (Doug Bennett) Golf courses get a certain amount of water at the normal prices, and if they exceed that, the pricing goes exorbitant. They literally cannot afford to break their water budget and the conversions help them stay within those water budgets. (narrator) But resorts and recreation are only a small part of the story.
Much more water goes to the residents who have moved to the desert valley in the last 30 years. And the Southern Nevada Water Authority is responsible for supplying it. Can I find a way through conservation to share the water that the existing residents are using with the new residents coming in? The single biggest use of water in this valley is irrigating landscaping.
So we’ve been steering people towards much more water-efficient plantings and, in fact, that is our single biggest water conservation program.
(narrator) The solution for Las Vegas is people working together and sharing a limited amount of water. Everybody has to reduce their water use, but everybody gets the water they really need. Both energy and water are intricately related to our quality of life. Conserving energy conserves water. And we all need to be participating in the solution.
Water and electricity are like air to us. We don’t think about it we just assumed that when we breathe, we should have good air. We assume that when we turn the tap on, there should be water.
(Doug Bennett) You can’t get anywhere by simply having the farmers point at the cities and the cities at the farmers. You really have to understand the bigger picture so that you can know what those choices are, what the trade-offs are.
(Gerry Groenewold) We’re a very significant energy consuming culture. And so if we’re not going to have thermoelectric plants, what are we going to replace them with? We need to look more and more technological solutions to conservation and reuse and so on. We have to understand the resource we have to understand its limits we have to understand our needs; I think if we really focus on that, we can dramatically change water use in the energy industry.
(Carl Bauer) We can’t have everything Yes, there is going to be some decisions that have to be made.
Bottom line, I would say, being responsible citizens will solve a lot of these issues if we are willing to be responsible in a respectful way to one another. (man) Funding Provided by the U.S. Department of Energy, The National Energy Technology Laboratory, The Energy and Environmental Research Center’s Northern Great Plains Water Consortium, and the Members of Prairie Public.
