Print 45 comment(s) - last by Darkskypoet.. on Mar 19 at 11:01 PM

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approximately 3 times more water is consumed (0.32 versus 0.07–0.14 gallons/mile) and over 17 times more water is withdrawn (10.6 versus 0.6 gallons/mile) primarily due to increased water cooling of thermoelectric power plants to accommodate increased electricity generation.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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By pauldovi on 3/12/2008 10:00:35 AM , Rating: 2
~11 Gallons per Miles seems a little ridiculous to me.

I think the best thing in the direct future is small diesel motors with a electric motor and a battery / capacitor bank to store the energy.

As we move into the future, who knows what the solution will be. One this is for sure, it won't be hydrogen. Hydrogen will always be the fuel of the future. It takes way to much energy to get hydrogen fuel.

RE: Really
By ChronoReverse on 3/12/2008 10:23:14 AM , Rating: 5
The water is used for cooling. It's not like it DISAPPEARS.

RE: Really
By Master Kenobi on 3/12/2008 10:40:35 AM , Rating: 1
But it has to come from somewhere. In a time when we are already strapped for water in many areas (especially during the summer), this will take more of that water out of use by everyday people. I suppose the solution to this is to pump in ocean water and purify it for regular use. Will still likely need to pump water across country though for states that don't have easy access to ocean water.

RE: Really
By bighairycamel on 3/12/2008 10:49:42 AM , Rating: 2
But it has to come from somewhere.

Yes but the 10-11 g/mi factors in water used for cooling, which would be in a closed circuit being recycled over and over again. Sure an occasional top-off would be needed and a rare flush-and-fill, but minus this water used for cooling the number probably drops to something much more negligable.

I highly HIGHLY doubt the vehicle is consuming (a far different definition that using) 10-11 G/mi.

RE: Really
By pauldovi on 3/12/2008 11:41:40 AM , Rating: 2
Closed Circuit? What is going to cool that hot water?

Typically rivers are circuited through power plants and back out to the regular water.

Would be great if hot water supply came from Power Plants. :)

RE: Really
By TheWizardofOz on 3/12/2008 12:07:35 PM , Rating: 5
Ever heard of the term "radiator" ?

RE: Really
By Chris Peredun on 3/12/2008 1:10:53 PM , Rating: 5
Barring being arrested for violating the laws of thermodynamics, I imagine some of the heat could be recaptured and used to generate further power.

RE: Really
By stephenfs on 3/12/2008 1:43:22 PM , Rating: 3
A wise man once said, "In this house we obey the laws of thermodynamics!" -Homer Simpson

RE: Really
By Hoser McMoose on 3/13/2008 2:24:36 AM , Rating: 2
The wording might be a bit off, but if I understand the previous poster correctly there is no violation of any laws of thermodynamics here. Essentially capturing some of the waste heat is what a combined cycle thermoelectric power plant is all about. Pretty much all new natural gas and some new coal power plants use this concept.

The trick is not to get energy from nothing, it's just to raise the efficiency of energy conversion from ~30% up to ~40 or even 50%.

More energy converted to electricity means less energy wasted in heat and therefore less water needed to cool the power plant (not to mention less fuel and pollution).

RE: Really
By Captain Orgazmo on 3/13/2008 6:12:36 PM , Rating: 2
Oh yeah, great. Radiate all that extra heat back into the atmosphere, warm the planet, kill the seagulls, kill your kids. Why not just start carpet bombing our own cities right now?


RE: Really
By DragonMaster0 on 3/12/2008 7:27:17 PM , Rating: 2
Closed Circuit? What is going to cool that hot water?
How does a watercooled PC work?

RE: Really
By KristopherKubicki on 3/12/2008 8:48:42 PM , Rating: 2
Cooling your processor is not the same as cooling a nuclear reactor core. There are considerably different technologies of scale.

RE: Really
By Mitch101 on 3/13/2008 11:02:04 AM , Rating: 5
There goes overclocking a nuclear reactor.

Maybe thermaltake will come up with a nuclear reactor cooling solution. Fan noise might be a problem.

RE: Really
By geddarkstorm on 3/12/2008 11:33:59 AM , Rating: 3
And it has to go somewhere too. That water used for cooling can be piped right back in to circulation. Even if it's turned to steam, you have condensers to recapture most of the water.

Nonetheless, it is true that water supply must be kept in mind at all times when evaluating what technologies are practical to pursue, but I don't think it's such a "doomsday" sounding problem as the research sounds first glance.

RE: Really
By clovell on 3/12/2008 5:58:37 PM , Rating: 2
> These increases in water usage represent approximately 0.2–0.3% (28) and 3% (27), respectively, of overall U.S. water consumption (100,000 Mgal/d freshwater in 1995) and withdrawal (408,000 Mgal/d in 2000)

From the manuscript.

RE: Really
By Grast on 3/12/2008 10:52:40 AM , Rating: 5
I believe the report is referring to the water use for all types of electrical generation. All forms of electrical generation are basically large steam plants with the exceptio of gas turbines. The fuel used to create the heat can be coal, oil, nuclear fission, and possibly fusion.

All of these technologies take huge amounts of water. Nuclear plant use vast quantities of water in evaprative towers.

Nuclear is the future and modern designs on the coasts can greatly reduce the requirement for large quantities of water by using sea water as the coolant for the secondary steam plants. I digress.

The main point of the argument is that energy generation is not very environmentally friendly no matter how much we try. Until Star Trek style energy becomes available, we will always be threading the needle between electrical generation and the polutants it generates.


RE: Really
By jRaskell on 3/12/2008 12:21:18 PM , Rating: 2
The gallons withdrawn is a bit misleading. The report referenced explicitly states what is meant by consumed and withdrawn. To quote the report directly (link available in the article)

"Water withdrawal pertains to water that is taken from a concentrated source, used in a process, given back from whence it came, and available again for the same or other purposes."

I do think the information provided in the report is valid, and should certainly be a consideration, but I don't see it as a concern except maybe for locations that regularly deal with substantial water shortages. The water required for these processes does not need to be drinking water. The Hoover dam obviously has a HUGE water withdrawal figure, but I seriously doubt it has any bearing on general water availability in that area. If anything, the huge lake that dam created likely has a positive affect on water availability in that area.

RE: Really
By Ringold on 3/12/2008 3:44:12 PM , Rating: 2
My home state of Florida is and has been furiously trying to secure future sources of water; county governments on the east coast did a study and found a desalination plant is now their most cost-effective option.

I've heard California is having its water problems, and Georgia Conservatives sounded like they were about to form their own militia and storm the Army Corps of Engineers at Lake Lanier to stop the flow of water being sent here to Florida.

I don't know about Texas, New York or Ohio, but Florida and California right there means a huge portion of the US population lives in an area experiencing acute water shortages.

If they could use salt water, then no problem.

RE: Really
By boogle on 3/13/2008 8:20:46 AM , Rating: 2
I think the best thing in the direct future is small diesel motors with a electric motor and a battery / capacitor bank to store the energy.

Why? The car is heavier, has dirty great lithium ion batteries (not the most environmentally friendly) and a fossil fuel engine. MPG can only go down, even if it's just due to the added weight. But converting energy is never 100% efficient, so the conversion of energy from the diesel engine to the batteries, and then from the batteries to the electric motor, and then from the electric motor to the wheels is just asking for lower MPG.

Hybrid cars are thoroughly pointless from an increased efficiency perspective. They're great for moving pollution out of urban areas, but other than that they're not much different from a normal car. Their MPG figures are only better (in the US) because they have more efficient fossil fuel engines than the vast majority of US vehicles.

RE: Really
By kkwst2 on 3/19/2008 5:15:47 PM , Rating: 2
Well, that's not strictly true. I would agree that in their current design (both drive the powertrain directly) they're not very useful. However, a hybrid in which the diesel charges the battery and electric motor powers the wheels is much more efficient than just an ICE. There are designs coming out like this, one I think from Chevy. If the ICE can run at one RPM it becomes significantly more efficient.

RE: Really
By Darkskypoet on 3/19/2008 11:01:51 PM , Rating: 2
Additionally, and I don't have figures, but i am sure someone does, the ability to use generators in wheel hubs to drive and brake the vehicle is a definite advantage.
(Yes I know most are done through transmission still)

Especially considering standard ICE vehicles simply dump their momentum to heat, friction, noise, etc. Regenerative braking, is one of the best parts of a hybrid / electric design, and is one of the reasons why Hybrids have much better city mileage, then standard ICE's. Further, the ability to simply cut the engine out in a lot of stop and go situations further adds to the 'in-city' benefit.

Highway driving, and efficient Freeway systems do negate the advantages of a Hybrid considerably, I would even say it probably turns the Hybrid into something more inefficient then an ICE. However, for many cities experiencing grid lock regularly, the small generator / wheel well type electric motors should give better AWD handling, great regenerative braking characteristics, and a much more efficient drive for stop and go traffic.

The weight increase should also be quite low, considering you would lose the need for a heavy main drive train / transmission, and instead have a small ICE as generator, and 2 or 4 electric motors, depending upon design. As well if well designed, you may also lose the need for the heavier cooling systems / hydraulics standard in many cars. However, I am uncertain as to that point.

Clearly, there are better hybrid designs available then those utilizing a FULL ICE System and A FULL Battery system shoehorned into an ugly vehicle. (*cough* Prius)

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