[Dean's World] Aziz P: energy inputs

[notify at powerblogs.com]

Posted by Aziz P:
energy inputs
http://www.deanesmay.com/posts/1144076570.shtml


   this is the kind of thing that [1]physicists are always getting
   frustrated about:

     CNW's findings indicate that a hybrid consumes more energy overall
     than a comparable conventionally powered model. It judged showed
     that the Honda Accord Hybrid rang up an Energy Costs Per Mile of
     $3.29, while a gas-powered Accord was significantly cheaper at
     $2.18/mile. The study concludes that the average of all 2005 U.S.
     market vehicles was $2.28/mile.

     The reasoning goes that hybrids use up more energy to manufacture,
     as well as consume more resources in terms of the assembly (and
     eventual disposal) of things like batteries and motors. By CNW's
     reckoning, the intrinsically lower complexity of, say, a Hummer H3
     ($1.949/mile) actually results in lower total energy usage than any
     hybrid currently on the market, and even a standard Honda Civic
     ($2.42).

   While I am in no position to evaluate the methodology, I think that it
   is critical to assess overall net energy rather than simply energy at
   one stage in any supposed "green" initiative.

   Many environmentalists seem to assume that hybrid vehicles magically
   appear - generated by fairy dust and Mother Gaia - and then at the end
   of their lifespan will simply be re-absorbed into the ecosystem.

   I think that hybrid technology is important and that buying hybrids is
   a good idea because it will help reduce manufactring costs and
   increase economies of scale. After all, today's gasoline engine is
   orders of magnitude more efficient than the one in the Model T.

   However, buying a hybrid is definitely a poor choice of you are out to
   save money. I'll leave the simple math as an excercise for the reader
   - just compare a 25 mpg vs a 50 mpg fuel economy, with the latter
   costing an additional $5000, and see how many years it takes to break
   even (with gasoline at $2.50 a gallon and driving 15,000 miles a
   year).

   And as for the green aspects of hybrids, regardless of the specific
   numbers above, it is quite reasonable to assume that the overall
   energy cost of production is substantially higher than a conventional
   vehicle. Denying this fairly obvious fact is detrimental to
   credibility on green issues.

   The irght long term solution for automobiles is to go fully electric.
   Hybrids provide an easy vector for improvement of battery technology
   with immediate fiscal incentive for the automakers to drop the big R&D
   bucks. But no one driving a hybrid has any real reason to feel
   particularly green.

   I plan on considering a hybrid next, myself.

   (via [2]Brian)

References

   1. http://www.autoblog.com/2006/04/01/new-study-full-size-suvs-consume-less-energy-over-lifetime-than
   2. http://www.grotto11.com/blog