POWER October 2010 - 92

COMMENTARY
The Nexus of Energy
and Water
By Edward Walsh
T
he age-old adage " water and electricity don't mix " does
not apply to 21st-century infrastructure planning. The two
entities can no longer be viewed as separate commodities.
The demands on both are intertwined, so solutions for meeting
new and growing challenges associated with water scarcity and
carbon regulations must also be integrated.
Water is essential to the operations of thermal power generation,
which accounts for approximately 90% of all U.S. electric
generation. A telling figure from the National Renewable
Energy Laboratory shows that the amount of water used to
produce household electricity actually exceeds direct household
water use.
In turn, treating, processing, and moving water is very energy
intensive. According to The Alliance to Save Energy, energy consumed
to supply water may easily " eat up half of a municipality's
total budget. " The U.S. Energy Information Administration
reported that in 2005, municipal and industrial water supply and
wastewater treatment systems' electric consumption was equivalent
to what was used to run refrigerators across the country.
Water Is a Fuel
Today, water is a leading issue for power providers. In Black &
Veatch's 2009/2010 Strategic Directions in the Electric Utility
Industry Survey, water supply was second only to carbon regulation
as the most pressing environmental concern. This concern is
validated by the Energy Law Journal's observation that water issues
have complicated construction or operation of power plants
in at least 14 states.
Regulations and restrictions on water resources will require
new processes and planning for ensuring a sustainable power
supply. One way to begin this new thought process is to view
water as a fuel. Water is a fuel for generating electricity and for
powering local, regional, and national economies.
According to the U.S. Geological Survey, water withdrawals
for energy are approximately equal to those for agriculture,
each making up about 40% of freshwater withdrawals.
However, power generation only accounts for 3% of all water
consumption, as compared to agriculture's 85% of all consumption.
Most of the water used for power generation is eventually
returned to the source. As a result, national and state water
discharge regulations can also impact the operations of a power
plant, as do environmental regulations governing emissions
and waste products.
Carbon emissions and climate change are central to planning
for our nation's future electric energy supplies, requiring
providers to look at balanced generation portfolios. Nuclear,
coal (assuming carbon capture will be part of future " clean "
coal projects), solar thermal, and biofuels are widely viewed as
key areas for addressing potential carbon and climate change
92
legislation. According to The World Resources Institute, these
are also the power plant technologies that withdraw the largest
amounts of water.
Just as we look toward modified generation portfolios to
lower carbon emissions, we also must look for a balanced portfolio
that reduces water withdrawal and consumption. When we
think about water as a fuel, we can readjust our thinking and
change the conversation. We need to ask the same questions
about water that we ask about fossil fuels. What are the conservation
strategies? Where does it come from? Is it a sustainable
resource? What are its most effective uses?
Addressing the Nexus of Energy and Water
Climate change legislation, if enacted, would have far-reaching
impacts beyond the electric power industry. All industries, including
the water and wastewater treatment sectors, must plan
now on how it might impact their operations. In this regard, it
is important for water and energy providers to work together.
Integrated planning between water and electric utilities has
achieved proven and sustainable results in reducing costs and
freshwater usage.
One example of a successful collaboration is between the city
of Mankato, Minn., and a power generator. The power generator
needed water to cool its new plant near Mankato. The city
needed to upgrade its wastewater systems in order to meet new
environmental discharge regulations. The city offered its wastewater
effluent to the power generator for plant cooling and, in
turn, the power generator agreed to build a water reclamation
facility that would address the stricter discharge regulations. By
transferring treated wastewater to the power plant, both entities
effectively cut costs and reduced demand on the local surface
and groundwater supplies by nearly 680 million gallons per year
and improved the quality of water that is returned to the river.
(Editor's note: See the Brandon Shores Top Plant story in this
issue for another example.)
Taking Action
Perhaps the single most important point to remember is that
there is no all-inclusive solution for addressing these complex
challenges. Each city, watershed, and region faces unique challenges
and opportunities as additional air, carbon, and water
regulations are enacted at the local, state, and federal levels.
The convergence of new patterns in population, weather, energy
production, and climate is demanding that we approach our
water resource planning for power generation in a more holistic,
integrated fashion. This requires a new mindset about water and
its use, management, and value, and we must begin today. ■
-Edward Walsh (walshej@bv.com) is executive vice president of
Black & Veatch Corp.'s global energy business.
www.powermag.com
POWER | October 2010
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POWER October 2010

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