Monday, March 10, 2008

PHEV/EVs and water - Finally a good article

It seems that the first paper (regarding water for electric vs. gasoline miles) on our work on the "water intensity of transportation" has gotten quite a bit of attention in the media. I've reported on this already, but included here is finally a good and responsible article that properly demonstrates the scope of the issue.

For an example of an article that does a good job, see the following:

ScienceNOW published this article - online today (3/10/08)

Bottom line (I repeat), electric and plug-in hybrid electric vehicles will use more water because people will charge their cars from the general electric grid. This grid is dominated by thermoelectric power plants (coal, natural gas, and nuclear), and these plants consume and withdraw water as part of cooling. To lessen the water impact, we can focus on (1) generating electricity in thermoelectric plants using technology that consumes and withdraws less water and (2) using electricity from sources that don't consume and withdraw water (wind, PV solar).

For examples of articles that do a poor job, see any of the following:

- The quote below is very misleading and incorrect. The water intensity, or gallons/mile, for withdrawal is 17 times greater. This is not a 17-fold increase in water demand, even if all light duty vehicles (cars, trucks, SUVs) ran on full electric power, because water is withdrawn for many other purposes AND if all miles (2.7 trillion) in 2005 were driven on electricity, that would amount to about 900 billion kWh, when the entire nation generated 3,883 billion kWh without any measurable amount of PHEV/EVs. Thus, all light duty vehicle travel by electric miles would be only 23% more electricity (and associated consumption and withdrawal), NOT 17 times more. See misleading quote from article:

"Though most of this water is returned to the source (albeit at a higher temperature), a 17-fold increase in demand would pose a real problem for water-stressed regions, making power plants more vulnerable to shut down during times of drought. "

- The following quote is completely incorrect. The nation's water consumption (which includes that for irrigation, municipal use, mining, and thermoelectric generation) will NOT triple if we switch to PHEV/EVs. See above comment on the Popular Mechanics article, same argument goes for not tripling nation's water consumption with all electric light duty vehicle travel. See misleading quote from article:

"Michael Webber and Carey King, from the University of Texas at Austin, suggest that powering America's cars with electricity, rather than gasoline (petrol), could triple the nation's water consumption."

Have a good day.

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.

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 mention this.

For example:
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!