SOLAR TODAY®
JANUARY/FEBRUARY 2010
VOL. 24, NO. 1
By CAREY W. KING and
MICHAEL E. WEBBER
CAREY KING
HOLLY PORT
Some forms of solar energy require little or no water for cooling. They hold promise for resolving water conflicts in the American Southwest.
energy and water are interrelated in many ways. It takes energy to get clean water: We use electric power when we treat and
sanitize both our drinking water and our sewage. We also use water to run desalination systems, creating potable water from non-potable
resources. On the flip side, it takes water to generate energy. According to the Energy Information
Administration, hydropower provides 6 percent
of electricity in the United States and 17 percent
of electricity worldwide. Water is pumped into oil
and gas reservoirs to maintain pressure in older
wells. Perhaps most important, water is used to
cool the thermoelectric power plants that generate more than 75 percent of the United States’
electricity — 4,115 terrawatt-hours in 2008.
Less Water Can Mean Less Energy
Droughts can create water constraints that,
in turn, become energy constraints. The Southeastern United States came very close to experiencing this problem in 2007 and 2008. Several
nuclear power plants, dependent on lakes for
cooling water, came close to their minimum
water requirements. France had to reduce the
output of several nuclear plants during a heat
wave and drought in 2003.
Meanwhile the mighty Colorado River has
been experiencing a multiyear drought. In 2009,
Lake Mead, formed by Hoover Dam and constituting the water supply for Las Vegas, fell to its
lowest August level since 1937, according to the
U.S. Bureau of Reclamation. Research from the
Scripps Institution of Oceanography at the University of California at San Diego warns there’s
a 50 percent chance that, if nothing is done to
curtail water consumption, Lake Mead’s surface
will fall too low to produce hydropower by 2017.
There’s an equal chance the lake will simply run
dry by 2021.
Carey King works in energy and resource analysis at the
University of Texas Center for International Energy and
Environmental Policy ( jsg.utexas.edu/cieep). He holds
a Ph.D. in mechanical engineering with a specialty in
energy systems modeling and optimization. Contact
him at careyking@mail.utexas.edu.
Michael E. Webber is associate director of the Center
for International Energy & Environmental Policy, co-
director of the Clean Energy Incubator and assistant
professor of mechanical engineering at the University
of Texas at Austin (visit webberenergygroup.com for
more information). He can be reached at webber@
mail.utexas.edu.
