[SGVLUG] [OT]Hybrids and trains (was fuel prices and the dollar)

[David Lawyer]

On Fri, May 16, 2008 at 03:21:03AM -0700, Christopher Smith wrote:
> David Lawyer wrote:
>>> From: x at xman.org (Christopher Smith) Date: Wed May 14 09:39:40
>>> 2008
>>> In truth though, airplanes are much more fuel efficient than
>>> that.  Modern aircraft typically get 3.5 litres per 100 passenger
>>> km, or roughly 70 miles per passenger gallon, which does seem like
>>> 10x worse than some of the more fuel efficient trains, but if you
>>> look at American rail systems, the fuel economy is much, much worse
>>> (I imagine partly due to low occupancy rates), so that might be how
>>> it balances out. In general, the jet has the advantage of less
>>> friction, although that whole "staying aloft" thing works against it
>>> a fair bit.
>>>     
>>
>> For a history of passenger-miles/gallon for air transportation, see my
>>  "Fuel-Efficiency of Travel in the 20th Century"
>> http://www.lafn.org/~dave/trans/energy/fuel-eff-20th-3.html#air_eff
>>
>> For 2000 it's about 38 pass-mi/gal, but it seems that between 2000 and
>> 2005 there was about a 17% improvement.
> Yeah, we've been making even bigger strides than that. The Airbus claims  
> the A380 is another 17% better than any other aircraft designed today,  
> and Boeing's newer planes are also much more fuel efficient than their  
> predecessors (odd how this happens as energy prices go up eh? ;-). The  
> specific claim for the A380 is "2.9L/passenger/100km", although that  
> assumes a completely full plane and no cargo, but still this would seem  
> to suggest 3.5L/passenger/100km is a pretty real number (if only I could  
> find the original citation... ;-):
>
> http://www.cnn.com/2007/TECH/10/25/fsummit.climate.A380/index.html
>> Amtrak gets about 40 pass-mi/gal so it's worse than airplanes.  I
>> checked on reported train efficiencies in Europe and Japan where they
>> use electric trains and they fail to take into account that it uses
>> about 3 units of fossil fuel (or atomic energy heat) to generate 1
>> unit of electricity, resulting in reported train fuel efficiencies
>> about 3 times higher than they actually are.  Japanese trains often
>> have 3 seats on each side of the aisle which makes them more
>> energy-efficient, but could larger Americans fit in such seats?  This
>> is where Mark Twain's "damn lies and statistics" comes into play.
>>   
> Hmm... most of the claims I've seen for trains are at least twice as  
> good as that.

I've seen high claims and they are only true for ideal situations: a
train running on level ground with no stops, starts, or slowing down
for curves, all seats occupied, moderate speed, etc.  This
"hypothetical" train is a few times more energy-efficient than the typical
actual train.

> Maybe Amtrak just isn't efficient? It is a little unfair  
> though to translate everything in to fossil fuel consumption, as  
> electric trains open up the possibility of cheaper energy sources, such  
> as hydro.

You need to ask the question: if additional electricity is needed to
run a train, where will it come from?  Most likely fossil fuels since
the best sites for hydro are already taken.  And hydro isn't fully
renewable either.  I think it took about 30 years of electricity sales to
pay back the construction cost of Hoover Dam (near Las Vegas).  If you
were to consider real inflation (which per an article in the current
issue of Harpers is about double what the government claims it is)
then the payback time would be much longer.  Eventually dams silt up
and no longer serve as dams unless you can get rid of the silt (at
least that's what I've been told).  The energy it takes to build a dam
may be roughly proportional to its cost.

>>> From: x at xman.org (Christopher Smith)
>>> Date: Wed May 14 13:43:16 2008
>>> That said, oil production levels aren't growing too quickly these 
>>> days, so energy conservation measures (particularly significant ones, 
>>> like driving less and/or driving more fuel efficient vehicles) really 
>>> are the most effective way for us to alter the supply/demand 
>>> situation in the short term. In the long term, you need some other 
>>> source of energy (see:
>>> http://google.org/rec.html) to become more cost effective than  
>>> petrochemicals to really have a lasting impact.
>>>     
>>
>> I just don't think that there is any other source of energy that's
>> feasible.  I think we've underestimated the amount of embodied fuel
>> energy it takes to make alternative types of energy such as solar,
>> biofuels, etc.  For the case of solar, see
>> http://209.85.173.104/search?q=cache:5ND_gDdBnTwJ:www.nps.edu/drmi/docs/DRMI%2520Working%2520Paper%252006-02.pdf+photo-voltaics+%22working+paper%22+navy&hl=en&ct=clnk&cd=1&gl=us&ie=UTF-8
>> (WORKING PAPER SERIES 2006/02 Photo-voltaics Navy)
>>   
> Even without government subsidies, and when prices for fossil fuels were  
> 1/3 of what they were now, some alternative energy sources weren't  
> *that* much more expensive than fossil fuels (certainly a lot of them  
> are within an order of magnitude). Hydro is definitely cheaper, and if  
> we can get wind turbines that are just a hair more efficient, combined  
> with rising fossil fuel prices, that one seems likely to make it too.  
> Photovoltaics seem like they are making slow but steady progress along  
> those lines, and simpler photothermal solutions have fairly low energy  
> costs. Then there is wind power...
>>> From x at xman.org  Wed May 14 20:00:58 2008
>>> From: x at xman.org (Christopher Smith)
>>> As the price of petrochemicals goes up, so do the options for oil and 
>>> gas producers. If the prices get much higher, Canada may become the  
>>> richest source of oil reserves in the world within a few years. Not 
>>> to mention that wind power starts to become a really nice alternative 
>>> to coal/gas/oil, reducing our need to consume it for power 
>>> generation.
>>>     
>>
>> Wind power only is feasible due to subsidy, so it's not clear that it
>> actually saves energy when one counts embodied energy correctly.

> The federal subsidy for wind power is like 2 cents per kilowatt-hour  
> (there are state subsidies that help as well, but still). Given the  
> shifts we've seen in fossil fuel prices, I don't think those magical 2  
> cents are going to amount to much in the long term picture. While wind  
> turbines do require a fair bit of power to produce, their maintenance  
> costs are pretty trivial. I've seen EROI's computed for existing systems  
> in the 30's, and claims of newer systems that will double that. This is  
> all before significant economies of scale reduce wind's energy sink: the  
> manufacturing costs. Those kinds of numbers aren't that bad compared to  
> fossil fuels. Given the same accounting principles, I just can't see how  
> flaws in the calculations would change the story to wind being such a  
> loser compared to fossil fuels.
For wind, if it's a loser it's not a big loser.  But we just don't
know.
>
> As far as I can tell, the big downer with wind is that currently they  
> don't like having wind generators near populations (which tend to be  
> where the energy is used), because of fears of turbines flying apart and  
> killing people (and surely there are ways to address that more sanely).
>>   See
>> the above link for Photo-voltaics.  I point out in my "in progress"
>> Human Energy Accounting that the human energy used to make things is
>> not being accounted for properly in embodied energy studies, as does
>> the Photo-voltaic article.  But my article still needs a lot of work.
>> It's at: http://www.lafn.org/~dave/energy/human_energy.html
>> 			David Lawyer
>>   
> One would imagine that factories can pretty much bang out turbines  
> without too much human intervention (maybe I'm wrong about this), and of  
> course the prohibitive energy costs of making the metals and such *are*  
> taken in to account, so I'm having a hard time imagining how the human  
> factors could really close the gap that much.

But it's the human energy that was put into infinite supply chains
that goes to make and install the wind turbines and towers.  The
chains are infinite in length since every component has other
components that go into in and so on ad infinitum.  But if you trace
back far enough you start getting into loops and many components are
counted an infinite number of times.  But the sums of the energy from
all the infinite number of steps converges to a finite sum.  Like
adding 1 + 1/2 + 1/4 + 1/8 + ... = 2.  But of course it's much more
complicated.
			David Lawyer