Net Energy: More Harm than Good?

Abstract: Ener­gy out­puts from ethanol pro­duced using corn, switch­grass, and wood bio­mass were each less than the respec­tive fos­sil ener­gy inputs. The same was true for pro­duc­ing biodiesel using soy­beans and sun­flower, how­ev­er, the ener­gy cost for pro­duc­ing soy­bean biodiesel was only slight­ly neg­a­tive com­pared with ethanol pro­duc­tion. Find­ings in terms of ener­gy out­puts com­pared with the ener­gy inputs were:

• Ethanol pro­duc­tion using corn grain required 29% more fos­sil ener­gy than the ethanol fuel produced.
  
• Ethanol pro­duc­tion using switch­grass required 50% more fos­sil ener­gy than the ethanol fuel produced.
  
• Ethanol pro­duc­tion using wood bio­mass required 57% more fos­sil ener­gy than the ethanol fuel produced.
  
• Biodiesel pro­duc­tion using soy­bean required 27% more fos­sil ener­gy than the biodiesel fuel pro­duced (Note, the ener­gy yield from soy oil per hectare is far low­er than the ethanol yield from corn).
  
• Biodiesel pro­duc­tion using sun­flower required 118% more fos­sil ener­gy than the biodiesel fuel produced.
  

• Ther­mo­dy­nam­ics of the Corn-Ethanol Bio­fu­el Cycle (7/2006) (see abstract)
  
  “inef­fi­cient solar cells pro­duce ~100 times more elec­tric­i­ty than corn ethanol”
  
• Bio­fu­els Papers 
  • Sci­ence Let­ters: Rebut­tals to the bio­fu­els arti­cles in Jan. 27, 2006, Science
  • The real bio­fu­el cycles, Tad W. Patzek, Sup­port­ing Online Mate­r­i­al to the Let­ter in Sci­ence, Vol. 312, p. 1747, 26 June 2006
  • The Earth, Ener­gy, and Agri­cul­ture, Tad W. Patzek, Paper pre­sent­ed at the Cli­mate Change and the Future of the Amer­i­can West — Explor­ing the Legal and Pol­i­cy Dimen­sions, June 7–9, 2006, Boul­der, Colorado
  • Ethanol Pro­duc­tion Using Corn, Switch­grass, and Wood; Biodiesel Pro­duc­tion Using Soy­bean and Sun­flower, David Pimentel and Tad W. Patzek, Nat­ur­al Resources Research, Vol. 14, No. 1, March 2005
  • Ther­mo­dy­nam­ics of ener­gy pro­duc­tion from bio­mass, Tad W. Patzek and David Pimentel, Crit­i­cal Reviews in Plant Sci­ences 24(5–6), 327–364, 2005
  • Ther­mo­dy­nam­ics of the corn-ethanol bio­fu­el cycle, Tad W. Patzek, Crit­i­cal Reviews in Plant Sci­ences 23(6), 519–567, 2004
  • UC sci­en­tist says ethanol uses more ener­gy than it makes A lot of fos­sil fuels go into pro­duc­ing the gas sub­sti­tute — Eliz­a­beth Svo­bo­da, Spe­cial to The Chron­i­cle Mon­day, June 27, 2005, Page A‑4
  • Pro­ceed­ings of the Ener­gy Analy­sis Work­shop on Method­ol­o­gy and Con­ven­tions, 25–30 August 1974, Inter­na­tion­al Fed­er­a­tion of Insti­tutes for Advanced Study, The Nobel House, Stock­holm, Sweden 
  • Pro­ceed­ings of the Work­shop on Ener­gy Analy­sis and Eco­nom­ics, 22–27 June 1975, Inter­na­tion­al Fed­er­a­tion of Insti­tutes for Advanced Study, Lid­ingö, Sweden
  • Shee­han, J., Camo­bre­co, V., Duffield, J., Gra­bos­ki, M., and Shapouri, H. 1998, Life Cycle Inven­to­ry of Biodiesel and Petro­le­um Diesel for Use in an Urban Bus, Final Report NREL/SR-580–24089, Nation­al Renew­able Ener­gy Lab­o­ra­to­ry, Gold­en, Col­orado 80401
• Ethanol from Corn: Just How Sus­tain­able Is It?
  
• Ethanol from Corn: Clean Renew­able Fuel for the Future, or Drain on our Resources and Pockets?
  

• Bio­fu­el Skep­tic Extra­or­di­naire
  
  By Tom Philpott, 08 Dec 2006
  
  
  
  An inter­view with David Pimentel
  
  
  
  “No. I don’t care what kind of imag­i­na­tion you have, it won’t work.“
  Ethanol Fuels: Ener­gy Bal­ance, Eco­nom­ics, and Envi­ron­men­tal Impacts are Neg­a­tive (Nat­ur­al Resources Research, June 2003)
  Lim­its of Bio­mass Uti­liza­tion (Ency­clo­pe­dia of Phys­i­cal Sci­ence and Tech­nol­o­gy, Mar 2001)
  Ethanol fuel from corn fault­ed as ‘unsus­tain­able sub­si­dized food burn­ing’ in analy­sis by Cor­nell scientist