Natural gas
is replacing coal
in the U.S.
because of the
lower price.
Note: The amount of
water use for coal mining
and fracking is similar,
Renewables
are replacing coal
in the U.S. because of
the reduction of pollution.
These transitions have
one thing in common:
Saving many billions
of gallons of water !
The cooling systems
in natural gas electricity
power plants use
much less water
than those in coal plants.
40% of
all water use
in the U.S.
currently goes
to cooling
thermoelectric
power plants.
Avner Vengosh,
professor of geochemistry
and water quality at
Duke's Nicholas School
of the Environment,
said:
"The amount of water used
for cooling thermoelectric plants
eclipses all its other uses
in the electricity sector,
including for coal mining,
coal washing, ore and gas
transportation, drilling
and fracking" .
"For every megawatt
of electricity produced
using natural gas
instead of coal,
the amount of water
withdrawn from local rivers
and groundwater is reduced
by 10,500 gallons,
the equivalent of a
100-day water supply
for a typical American
household," said
Andrew Kondash,
postdoctoral researcher
at Duke University,
who led a study
as part of his
doctoral dissertation,
under Avner Vengosh.
Water used by
a power plant ,
and never returned
to the environment,
drops by 260 gallons
per megawatt-hour.
So if the rise of shale gas,
and the decline of coal,
continues through
the next decade,
by 2030 about
483 billion cubic meters
of water will be saved
each year, the Duke
study predicts.
If all coal-fired power plants
are converted to natural gas,
the annual water savings
will reach 12,250 billion gallons
—that's 260%
of current annual
U.S. industrial
water use.
Water use
per kilowatt
of electricity,
for renewable
solar and
wind energy,
is only 1% to 2%
of coal or
natural gas's
water intensity.
Sources:
Andrew J Kondash et al,
Quantification of the water-use
reduction associated with the
transition from coal to natural gas
in the U.S. electricity sector,
Environmental Research Letters
(2019)
Replacing coal with gas
or renewables saves
billions of gallons of water
(2019, October 22)