Skip to main content

Real Prospects for Energy Efficiency in the United States (2010) / Chapter Skim
Currently Skimming:

Appendix D: Definitions of Energy Efficiency
Pages 315-316

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 315...
... Both of the measures of energy efficiency defined above would be termed first-law efficiency (derived from the first law of thermodynamics) , being based simply on actual energy use and not taking into account such things as the excess entropy due to the irreversibility of real processes.
Read the entire page →
From page 316...
... Hence, for a perfect process, the denominators in these measures would be zero. No real process achieves the thermodynamic limit, of course, and so no real process has an infinite efficiency according to this last kind of definition.
Read the entire page →

Key Terms

  • free energy
  • miles driven
  • real process
  • process achieves
  • efficiency defined

  • total energy
  • direct unit
  • iron produced
  • ore smelted
  • entropy due

  • efficiency according
  • explicitly stated
  • infinite efficiency
  • rarely encounters
  • specified time

  • real processes
  • gibbs free
  • stated definition
  • efficiency terms
  • thermodynamic limit

  • energy required
  • perfect process
  • based simply
  • actual energy
  • energy expended

  • smelting process
  • process subject
  • son based
  • excess entropy
  • people tend


    • This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
    More information on Chapter Skim is available.