WASHINGTON, D.C., September 19, 2012 - Huge
demands on increasingly scarce water are a major hidden cost of a
"business as usual" approach to American electricity generation
that needs to be more fully understood by policymakers and the
public, according to a new Synapse Energy Economics, Inc.
report prepared for the nonprofit and nonpartisan Civil Society
Institute (CSI) and the Environmental Working Group (EWG).
The new analysis, "The Hidden Costs of Electricity:
Comparing the Hidden Costs of Power Generation Fuels," is
available online at http://www.CivilSocietyInstitute.org.
Six fuels used to generate electricity --- biomass, coal,
nuclear, natural gas, solar (photovoltaic and concentrating solar
power), and wind (both onshore and offshore) - are analyzed in the
following categories: water impacts, climate change impacts, air
pollution impacts, planning and cost risk, subsidies and tax
incentives, land impacts, and other impacts.
Examples of the water-related findings in the report include the
Nuclear power has critical cooling requirements that require
huge amounts of water. Roughly 62 percent of U.S. nuclear plants
have closed-loop cooling systems. Reactors with closed-loop systems
withdraw between 700-1,100 gallons of water per megawatt hour (MWh)
and lose most of that water to evaporation. Water withdrawals are
even higher at open-loop cooled nuclear plants, which need between
25,000-60,000 gallons per MWh. Most of the water is returned, but
at a higher temperature and lower quality.
In addition to fouling streams and drinking water through mining
and coal-ash dump sites, coal-fired power relies heavily on
closed-loop cooling systems which withdraw between 500 and 600
gallons of water per MWh and lose most of this via evaporation.
Withdrawals for open-looped cooled coal-fired power plants are
between 20,000-50,000 gallons per MWh. Most of the water is
returned, but at a higher temperature and lower quality.
Under a so-called "Clean Energy Standard," biomass would become
a much larger source of U.S. electricity generation; however,
biomass also requires vast amounts of water. The report notes that
a typical 50 megawatt (MW) biomass plant could withdraw roughly 242
million gallons of water per year and lose most of this. Adding 10
of these plants in a region would use 2.42 billion gallons of water
per year. For dedicated energy crops, water use for irrigation can
be considerable. One study estimates water use for most crops
between 40,000 and 100,000 gallons per MWh, with some crops
exceeding this range.
In 2010, EPA estimated that fracking shale wells can use
anywhere from two to 10 million gallons of water per well. The
water is often extracted from on-site surface or groundwater
supplies. Such huge water withdrawals raise serious concerns about
the impacts on ecosystems and drinking water supplies, especially
in areas under drought conditions, areas with low seasonal flow,
locations with already stressed water supplies, or locations with
waters that have sensitive aquatic communities.
By contrast, wind and solar photovoltaic power requires little
water in the electricity generation process. Concentrating solar
power requires water for cooling purposes, but new technologies are
placing greater emphasis on dry cooling. Solar power plants with
dry cooling use only around 80 gallons per MWh - about a tenth of
the low-end estimate for nuclear power and one-sixth of the low end
estimate for coal-fired power generation.
Grant Smith, senior energy analyst, Civil Society Institute,
said: "The government and energy industries are literally
flying blind as they plan for continued reliance on coal, natural
gas, nuclear power and industrial biomass to meet our energy needs.
Each of these is water intensive and leads to pollution of water,
which is increasingly scarce and in competition for other uses such
as agriculture and other commercial uses."
Other water-related data highlighted in the report includes the
The full picture for nuclear power water use may be even more
dramatic. Estimates of lifecycle water use for three European
reactors range from 2,600 to 6,900 gallons per MWh, not including
cooling water use. (This compares with a lifecycle analysis of a
parabolic trough solar thermal power plant at 1,240 with wet
cooling and just 290 gallons per MWH for dry cooling.) In addition,
nuclear wastewater production ranges from 6.3 to 7.4 gallons per
Coalbed methane recovery of natural gas depletes ground water:
one estimate puts total groundwater removed between 1997 and 2006
at an astounding 172 billion gallons.
Estimates of the lifecycle water withdrawals from wind projects,
including both onshore and offshore projects, range from just 55 to
85 gallons per MWh.
The full study is available here.