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Full of promises about saving the Earth and conserving energy, could automakers and visionaries be missing one big thing?

Even though automakers and environmentalists are pushing new electric and hybrid electric cars, claiming less pollution to make our Mother Earth unhappy with our wasteful ways, it seems they come with demons of their own. Well, maybe not so much.

The media has certainly been filled with talk of the cleaner cars lately. Everything from MIT's City Car to the Lightning Car Company's 700HP sports car to Chevrolet’s Equinox fuel cell SUV which DailyTech got to take for a little spin this January. What's the deal? Well, obviously if you have cars running on electricity, they aren't churning out megatons of air and water pollutants each year. Well, the cars won't be, but the whole "where does the power get made to power the cars then" quandary can be fought with later.

Today we'll make note of a much stranger side effect of all these silent, battery and (noble) gas driven people movers. From the University of Texas at Austin comes research projecting that there's going to be a pretty large quantity of one of our most precious natural resources gobbled up by these electrics. No, it's not oil, trees, hydrogen or even indium - we're talking about water.

It's not much of a shocker, it's true. Water is probably our most precious resource, but barring evils like pollution and hydrolysis, it's one of Earth's most abundant and easily renewable. So we make a bit more steam, what's the big deal, right? Let's let the research speak for itself for a moment.

We compare figures from literature and government surveys to calculate the water usage, consumption, and withdrawal, in the United States during petroleum refining and electricity generation. In displacing gasoline miles with electric miles, approximately 3 times more water is consumed (0.32 versus 0.07–0.14 gallons/mile) and over 17 times more water is withdrawn (10.6 versus 0.6 gallons/mile) primarily due to increased water cooling of thermoelectric power plants to accommodate increased electricity generation. Overall, we conclude that the impact on water resources from a widespread shift to grid-based transportation would be substantial enough to warrant consideration for relevant public policy decision-making. (PDF)

Wow. 10.92 gallons of water per mile. It's a pretty staggering number. Thinking that my daily commute used to be about 40 miles, not including zipping around town for random things, that's more than 400 gallons in one day. That's probably more than the average person uses all week between hygiene and self hydration.

On the whole the conclusion they come to isn't exactly life-threatening, but it could become a problem, as they point out, for areas where water shortages are already experienced yearly.

In reality, a study like this doesn't really say much about how much pollution we can or can't stop by converting to electric person delivery, other than the inflated power generation, and subsequent water requirements, that will be needed to charge all these cars (we weren't going to talk about that though). But it does point out a much simpler fact that though we may think we're heading in the right direction by cutting down our toxic pollution output, sometimes we forget to think about the simple things we might be sacrificing on the way.

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RE: 11 gallons/mile off
By KristopherKubicki (blog) on 3/12/2008 8:41:10 PM , Rating: 0
I'm not sure what the zing at DT is about. The report linked in this blog is on the hidden costs of these technologies. It's flat out disagreeing with other reports that claim 0.5 gallons per kW. So citing that report and claiming this one is bunk is sort of circular.

I'd suggest if you're upset with the University of Texas' report, then try to find fault with it rather than just dismissing it as a blogger trying to get attention. We get plenty of attention already, and guys like Levi get paid whether their article gets one hit or one million.

RE: 11 gallons/mile off
By MadMaster on 3/12/2008 10:09:45 PM , Rating: 2
Er, I re-read it. It says 10 gallons drawn. I find this misleading because only .5 gallons/kwh is evaporated, the rest of the water is reused or re injected to the river/lake (little impact on the environment except for heat pollution, but that is another small issue...).

The .5 gallons/kwh evaporated translates to 138 gallons per second at a 1 GWh power plant (coal or nuclear, both use similar steam turbine technology).

You can condense the water after running it through a steam turbine. The downside is that the steam turbine looses efficiency (because turbines work on a pressure differential), and the system is more complex/expensive. Such are the trade offs when engineering a power plant that uses steam.

Someone mentioned decentralized power. This makes A LOT of sense. An example of this is a combine cycle gas turbine. What they do is use the expanding hot gases (like a jet engine) when burning natural gas to turn a turbine(usually they are in the 10-100MW range). Then, it uses the hot exhaust to heat water which is in turned used to heat buildings. These systems are extremely efficient, hitting something like 80-90% efficient (compared to about 40% at a comparable coal or natural gas fired power plant). Systems like this are already implemented in many places.

The idea with this decentralization is to put one of these turbines every few blocks, circulate hot water, and generate electricity (btw, natural gas burns extremely clean). No need for a complex/expensive grid or extremely high heating costs...

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