By Jeff Thomas
Water and energy have been inexorably linked in human history at
least back to ancient Babylonia, where windmills helped power irrigation
as early as 1700 BC. Since then, that relationship has become one of
the great axioms of the industrial age – that is, it takes great volumes
of water to extract and convert energy resources, and often great
energy resources to move and treat water.
And in a world in which such resources are under increased pressure, the
interconnection between the two – known as the water-energy nexus to
some—may never have been more pronounced. That is particularly true in
the arid West, where rapidly increasing populations are expected to more
than double the need for more power by 2030, which will compete with
agriculture and growing municipal use for freshwater supplies.
“I think it’s really surprising people about the interconnection,” said
Tom Iseman, the water program director for the Western Governor’s
Association. “For a long time WECC (the Western Electric Coordinating
Council) has dealt with water supply and power generation scenarios, but
this is the first time we have worked on it from a regional
perspective.”
The numbers can be a little staggering. For instance, the Virginia Water
Resources Research Center estimates it takes 60 liters of water to keep
a single, 60-watt light bulb lit for 12 hours. Conversely, about 80
percent of the cost for supplying municipal water supply is the power
cost for treatment and distribution, according to the Nuclear Energy
Institute.
The fact that proposed power plants are finding it difficult to get
through water issues in places such as New Mexico and Arizona perhaps
isn’t startling, but in the last decade the issue is also cropping up in
wetter areas of the Rocky Mountain West. Two power plants have been
denied permits because of water impact issues in Idaho and the Corette
plant in Billings was denied water supply from the Yellowstone River
during critical low-flow months.
“I have talked to a lot of power companies, like Excel, which tell me
that they have surplus water rights, but even they are looking at the
upcoming constraints from a water perspective (up to and including
global warming),” said Stacy Tellinghuisen a Resource Analyst for
Western Resource Advocates in Boulder, Colo.
This hasn’t escaped the attention of the U.S. Department of Energy,
environmental advocates, water resource organizations and the electrical
supply organizations of our nation. The DOE has a national program
examining issues surrounding the water-energy nexus. WECC, which
oversees the grid and electrical reliability over much of the western
U.S. and parts of Mexico and Canada, has contracted with the agency’s
Sandia Lab in New Mexico for a state-by-state examination of where and
what future power plants could be located to best serve transmission
needs amid decreasing water availability.
The nexus necessarily deals with a large range of environmental issues
including clean water and air, carbon emissions, aquatic natural
resources, water and power conservation and renewable energy. But for
some people, that complexity makes this nexus the Norman McClean poster
child of environmental issues—that is: “Eventually, all things merge
into one, and a river runs through it.”
And that’s the primary reason it is the No. 1 issue for Tellinghuisen.
“I love rivers,” Tellinghuisen said bluntly. “And I think most water
managers recognize that we are now in a zero-sum game. There is no more
water available, so it’s simply a shift to a new user from an old user.
“The fact that it’s a zero sum game makes it even more pressing, but there are solutions that have multiple benefits.”
One solution that has little benefit is business as usual, in which
traditional coal-fired generating plants consume large amounts of water
account for the most of the energy consumed in most western states.
Your run-of-the-mill 500 megawatt coal-fired plant, which could serve a
city of about 140,000 people, consumes about 3,500 gallons a minute of
water in creating electricity, cooling and air treatment, said Mike
Hightower, who oversees research and evaluation of innovative
environmental and energy technologies for the DOE’s Sandia Lab in New
Mexico.
“That’s about 5 million gallons a day – the same water consumption as a
town of about 50,000,” said Hightower, adding that this figure doesn’t
take into account the water consumed or polluted in extracting and
cleaning coal before it is shipped to the power plant, not to mention
the carbon load that burning coal puts in our atmosphere.
Other thermal generating plants -– which create steam to move turbines
and water to cool the steam—don’t get a free pass either. A
thermonuclear plant employing the closed-loop cooling technology common
to the West consumes slightly more water than a coal plant. That’s about
23 gallons of water per day per household, or an additional 30 percent
of what that typical U.S. home consumes in water, according to the
Nuclear Energy Institute.
But natural gas-fueled power plants consume even slightly more water in
steam-powered plants, Western Resource Advocates (WRA) reported, though
other natural gas technologies can significantly reduce water
consumption. And the generation of natural gas is not without its own
additional water and environmental concerns.
Hydrofracking, where water and chemicals are pumped into wells to free
the natural gas through extended fractures in the rock, is now an
established norm in the West. That process can consume 3 million to 6
million gallons of water per well, and generates concerns that the
injected toxic chemicals may also contaminate ground and surface waters.
The Rocky Mountain West already uses a great deal of water in energy
exploitation, WRA reported, as much as 500 million gallons a day for oil
and gas recovery. Oil shale recovery has advanced quite a bit in
reducing water consumption since the idea was actively advanced in
western Colorado in the late 1970s, but will also come with a price.
“Oil shale is looking at consuming about three gallons of water for
every gallon of fuel produced,” Hightower said. “The projections are for
about 1.5 million barrels (of oil) per day, which is about 200 million
gallons of water a day. That is about the same as the water consumption
for Denver metropolitan area.”
In the West, almost all power plants have closed-loop systems for
cooling (think cooling towers) rather than once-through systems, which
require most water to be withdrawn but don’t actually consume as much
water.
Few of our rivers could in fact tolerate the warming influence of a
once-through system, but there are evolving technologies allowing for
dry cooling. The downside? These systems reduce the effectiveness of the
power plants and are not very useful in higher temperatures and that’s
precisely where power needs are growing fastest in the West – for
cooling in the summer months.
“The issues are great in the West, but we are also in a good position to
make changes,” Hightower said. “The renewable side of the equation is
very high in the West.”
But through the prism of the nexus, even renewable energy has a
different focus experts said. In a cursory glance of some of the
renewable options:
environmental consequence and could play a major role, especially given
the municipal water power needs, Hightower said. Conserve water and you
conserve energy, and visa-versa. That’s especially true in Colorado,
where large portions of the water supply for Front Range cities have to
be pumped from the Western Slope. And Denver’s water is actually much
less energy-intensive than desert cities such as Tucson, Phoenix,
Albuquerque and Las Vegas.
water, Hightower said. Of course, fully integrating this resource may
require extensive updates to the electrical transmission grid and
considerable backup power for when the wind stops blowing.
photovoltaic panels on every roof –- and we could all afford to put
them there -– this would be a natural, Hightower said. However, large
collective solar systems are usually also thermoelectric and can
actually outstrip coal, nuclear power and natural gas in water
consumption.
obviously has its upside in pollution-free power, but it also has an
associated water use due to evaporation. Hightower said that experts are
also examining the feasibility of generating electricity from existing
irrigation systems, which could be a significant power source here in
the West.
consumption, according to information from WRA. Some geothermal projects
are very water intensive, but others have low or negligible water
consumption.
loser when water consumption is taken into account. However, Hightower
said if water isn’t consumed in creating the biomass, for instance with
cellulosic ethanol from forests or grasses, the water needs could be
greatly less.
For years, energy policy has had little or nothing to do with water
policy, or the reverse for that matter, experts said. But according to
Iseman, that will likely change as policy makers in the West are quickly
coming aware of the nexus.
“I think there going to be some great opportunities to put some better strategies together,” he said.
Essays in the Range blog are not written by High Country News. The authors are
solely responsible for the content.
Originally posted at NewWest.net
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