The seemingly most reliable information on EROI is quite old and is summarized in chapter 12 of Hall et al. (1986). Newer information tends to fall into the wildly optimistic camp (high EROI, e.g. 10:1 or more, sometimes wildly more) or the extremely pessimistic (low or even negative EROI) camp (Tyner et al. 1998, Tyner 2002, Fleay 2006 and Caldicamp 2006). One recent PhD analysis from Sweden undertook an emergy analysis (a kind of comprehensive energy analysis including all environmental inputs and quality corrections as per Howard Odum) and found an emergy return on emergy invested of 11:1 (with a high quality factor for electricity) but it was not possible to undertake an energy analysis from the data presented (Kindburg, 2007). Nevertheless that final number is similar to many of the older analyses when a quality correction is included.
Figure 9. EROI for nuclear power plotted vs. year of analysis. (Source Robert Powers).
Click to Enlarge.
Tyner was the author (or co-author) on the 1988 and 1997 reports which are examples of the lower EROI numbers -- less than 5:1. Tyner’s 1997 paper reported an “optimistic value” of 3.84 and a “less-optimistic” value of 1.86 and may be based on “pessimistic” cost estimates.
The amount of proven oil reserves awaiting to be exploited fell last year for the first time in a decade, according to new figures released today. The amount of crude left in the ground was 1.258trn barrels - 3bn less than this time last year. These figures, revealed in the BP Statistical Review of World Energy, are probably the result of a slump in drilling activity due to a fall in the price of oil last year - from $150 per barrel to $30. At today's rate of use however there is still enough oil to last the next 42 years, according to the oil company although those concerned about Peak Oil say we are closer to running out given demand is expected to rise strongly in the short-term.