As plug-in cars finally gain recognition as the
"cleaner/cheaper/domestic" solution requiring no new technology or
infrastructure, journalists aiming for controversy are looking
everywhere for critics and skeptics. On February 26 we saw USA Today
embellish an already-deficient article with a completely misleading
headline, "Plug-in cars could actually increase air pollution"
Now we learn electricity is fatally flawed because power plants use
substantial amounts of water for cooling (then return almost all of
it to its sources). The original story's lamentable headline,
"Thirsty electric cars threaten water resources," quickly evolved
into Popular Mechanics' over-the-top "Plug-in Cars Could Drain U.S.
Water Supply, Researcher Says"
We wish we could respond broadly and rapidly enough so that these
misrepresentations don't achieve a broad life, but as we see in
electoral campaigns and online memes, "going negative" is often
effective. (In the past we've heard urban myths including: solar
photovoltaics require more energy to manufacture than they generate
during their lifetime; nickel-metal and lithium batteries are also
energy intensive to manufacture and are poison when recycled, and a
Hummer is cleaner than Prius.)
Here's the original report, followed by our brief rapid response,
then comments from Carey King, author of the cited study, who thinks
PHEVs make sense and calls the headline "unnecessarily alarmist."
Finally, we add in an unrelated hit on PHEVs by venture capitalist
'Thirsty' electric cars threaten water resources
06 March 2008
They may not be gas-guzzlers, but electric cars have a raging thirst for water.
A comparison of the volume of coolant water used in the
thermoelectric power plants that provide most of our electricity and
that used in extracting and refining petroleum suggests that electric
vehicles require significantly more water per mile than those powered
The findings could bode ill for drought stricken areas in the event
of a large scale switch to plug-in vehicles.
"I wouldn't sound the alarm that this is going to ruin the day," says
Carey King from the University of Texas, Austin, US, noting that no
mass-market electric vehicle is currently available. "But looking
into the future, this is something we should take into account."
King and colleagues found that cars, light trucks, and SUVs running
off the electric grid consume three times more water and withdraw 17
times more water per mile than their equivalent gasoline-powered vehicles.
For electricity generation, "consumed" water is the amount of water
lost to evaporation whereas "withdrawn" water is the amount of
surface water a power plant uses and later returns to its source,
typically a nearby lake or river.
King says one way to mitigate water-use impacts of electric vehicles
is by switching to dry cooling - using forced air instead of water to
cool steam in power plants. The technology has been around for years
but remains more expensive than water cooling; something King says
could change as available surface water becomes more scarce.
Another alternative is to move away from thermoelectric energy
sources such as coal, nuclear, and natural gas, to renewable sources.
"If we use only wind or solar energy, water use would be essentially
zero," King says.
Paul Denholm of the US Department of Energy's National Renewable
Energy Laboratory in Golden, Colorado agrees that water scarcity will
become an increasing problem for utilities, but he doesn't think
electric vehicle usage will have much of an impact.
"As electricity demand increases in general, water requirements --
especially in drought prone areas -- will become increasingly
important," Denholm says. But "the overall impacts of plug-in
vehicles are modest in the larger scheme of things".
Denholm co-authored a 2007 study based on data from Colorado showing
that if 30% of gasoline-powered vehicles were replaced with plug-in
hybrid electric vehicles getting 39% of their energy from the grid,
the region would experience only a 3% increase in total electricity demand.
The current infrastructure could easily handle this increase because
most vehicles would be charged overnight during off peak hours.
"It's going to be several decades before we see enough plug-in
vehicles to have any kind of impact," Denholm says. "It's hard to say
if the grid we have now will be the same grid we have when we begin
to see a large number of plug-ins."
Journal Reference: ASAP Environmental Science and Technology (DOI:
FELIX KRAMER'S RESPONSE AT NEW SCIENTIST:
Grid Impacts Of Plug-in Cars
Thu Mar 06 18:20:29 GMT 2008
Let's focus on the main impact: greenhouse gas emissions, which are
about half as high for an electric mile as a gasoline mile (even on
the national, half-coal, power grid). When we get to secondary
impacts, if we compare gasoline to electricity, the latter is also
cheaper (under $1/mile equivalent) and domestic (in the US, we don't
use imported oil to power our plants. If we look ahead to "dirtier"
gasoline that could provide additional supplies, analysts who look at
the amount of water and other resources used in processing/extracting
oil from shale and tar sands are horrified. And I've seen estimates
that each gallon of ethanol derived from corn uses 500-1500 gallons of water.
Looking ahead, electricity can come from increasingly clean,
renewable sources, while gasoline is stuck or goes backward.
CAREY KING'S RESPONSE AT NEW SCIENTIST:
By Carey King
Sat Mar 08 04:16:09 GMT 2008
Thanks for your comments.
Personally, I love the idea of electric cars and PHEVs. I'm a member
of AustinEV, the local chapter of the Electric Auto Association. I
like PHEVs/EVs for the same reasons you mention.
Please look forward to our future work that does look at the water
impacts for other fuels like oil shale, tar sands, biofuels, etc.
This PHEV work was the beginning of an overall assessment.
See my blog (http://rationalenergy.blogspot.com/)
for some comments
related to this and another past article about our PHEV-water paper.
You'll see that I don't believe the water intensity is a hindrance
Keep up the good work!
SCIENTIST CAREY KING'S RESPONSE ON HIS OWN BLOG
Postdoctoral Research Fellow, Bureau of Economic Geology, University
of Texas at Austin
Friday, March 7, 2008
Another article about my PHEV/EV and water usage - unneccesarily alarmist
Another article, this time in New Scientist, has been written about
my paper on "water of the plugged-in automotive economy". See a
recent post on water used while driving on electric miles for my
basic take on how to interpret the analysis. [he distinguishes
between water withdrawal and water consumption at
Phil McKenna, the journalist and writer of the article, chose the
title " 'Thirsty' electric cars threaten water resources". This is an
unfortunately alarmist title. The article prompted some to blog on
the New Scientist page that I was against plug-in hybrid electric
vehicles (PHEV) or electric vehicles (EV). This is certainly not
true. Some suggested I must be paid or work for some petroleum or
natural gas company. This is also certainly not true.
I gave Phil information to present the scope and scale of electric
driving upon the electricity grid and water resources, but he didn't
* 1 million PHEV40s (PHEVs that have a 40 mile range) would drive
about 7.3 billion miles per year. This is about 0.3% of miles driven
by light duty vehicles.
* The resulting water consumption is 1.7 billion gallons, or ONLY
0.13% of water consumption already associated with power generation.
* The resulting water withdrawal is 76 billion gallons, or ONLY 0.11%
of water withdrawal already associated with power generation.
I, and my coauthor, chose to independently look at link between
energy and water. This work is a first foray into this area, and we
have also analyzed other fuels (biofuels, hydrogen, coal to liquids,
etc.) that is in the review process for publishing.
So ... NO ALARM. We have time to plan for 10s of millions of PHEVs,
let's get them on the road!
KHOSLA DISMISSES PHEVs
Meanwhile, Silicon Valley venture capitalist Vinod Khosla, while
backing some battery startups, is still betting mostly on ethanol,
now from corn, in the future from cellulose. He sees no alternative
to powering all of the miles driven by clean liquid fuels, while PHEV
advocates want to fuel most or all of the local miles electrically,
with an evolving mix of fuels providing the range extension. At the
Washington International Renewable Energy Conference conference in
Washington last week, CNET
reports him saying,
Expensive products like plug-in hybrid cars, which may be the
darlings of environmentalists, simply won't drive large-scale change,
he said. "Plug-in hybrids are irrelevant because they are too
expensive. Unless you can make 500 million or 800 million of those,
it won't matter," he said. His contention that plug-in hybrids are
irrelevant, or "toys," a case he made late last year at a conference,
brought fierce criticism from environmentalists.
-- -- -- -- -- -- -- -- -- -- -- --
Felix Kramer fkramer@...
Founder California Cars Initiative
-- -- -- -- -- -- -- -- -- -- -- --